CN114935714A - Power supply detection circuit, driving chip, controller and LED driving system - Google Patents

Power supply detection circuit, driving chip, controller and LED driving system Download PDF

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Publication number
CN114935714A
CN114935714A CN202210858736.7A CN202210858736A CN114935714A CN 114935714 A CN114935714 A CN 114935714A CN 202210858736 A CN202210858736 A CN 202210858736A CN 114935714 A CN114935714 A CN 114935714A
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voltage
value
driving chip
voltage value
temperature
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CN114935714B (en
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唐永生
申石林
黄立
刘阿强
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Chengdu Lipson Microelectronics Co ltd
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Chengdu Lipson Microelectronics Co ltd
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    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
    • G01R31/28—Testing of electronic circuits, e.g. by signal tracer
    • G01R31/2851—Testing of integrated circuits [IC]
    • G01R31/2855—Environmental, reliability or burn-in testing
    • G01R31/2872—Environmental, reliability or burn-in testing related to electrical or environmental aspects, e.g. temperature, humidity, vibration, nuclear radiation
    • G01R31/2874—Environmental, reliability or burn-in testing related to electrical or environmental aspects, e.g. temperature, humidity, vibration, nuclear radiation related to temperature
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
    • G01R31/28—Testing of electronic circuits, e.g. by signal tracer
    • G01R31/2851—Testing of integrated circuits [IC]
    • G01R31/2855—Environmental, reliability or burn-in testing
    • G01R31/2872—Environmental, reliability or burn-in testing related to electrical or environmental aspects, e.g. temperature, humidity, vibration, nuclear radiation
    • G01R31/2879—Environmental, reliability or burn-in testing related to electrical or environmental aspects, e.g. temperature, humidity, vibration, nuclear radiation related to electrical aspects, e.g. to voltage or current supply or stimuli or to electrical loads
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
    • G01R31/40—Testing power supplies
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B45/00—Circuit arrangements for operating light-emitting diodes [LED]
    • H05B45/30—Driver circuits
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02D—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN INFORMATION AND COMMUNICATION TECHNOLOGIES [ICT], I.E. INFORMATION AND COMMUNICATION TECHNOLOGIES AIMING AT THE REDUCTION OF THEIR OWN ENERGY USE
    • Y02D10/00—Energy efficient computing, e.g. low power processors, power management or thermal management

Abstract

The invention discloses a power supply detection circuit, a driving chip, a controller and an LED driving system, and relates to the technical field of LED driving, wherein the power supply detection circuit comprises a detection module, a voltage output module and a comparator, and the invention can quantize a first voltage value at a target working temperature or a target working voltage output by the detection module based on the combined action of the voltage output module and the comparator, further quantize a first quantized value of the first voltage value at the reference working temperature and a second quantized value of the first voltage value at a real-time working temperature according to the reference working temperature, and calculate and output the real-time working temperature of the driving chip; or the real-time working voltage of the driving chip can be obtained and output according to the reference working voltage, a third quantized value of the first voltage value under the reference working voltage and a fourth quantized value of the first voltage value under the real-time working voltage.

Description

Power supply detection circuit, driving chip, controller and LED driving system
Technical Field
The invention relates to the technical field of LED driving, in particular to a power supply detection circuit, a driving chip, a controller and a detection system.
Background
The LED display screen has the advantages of seamless splicing, natural and real color, clear picture, modularized maintenance, good display uniformity and the like, meets the requirements of the display screen on high definition, high fineness and close distance appreciation of display effect, and gradually becomes a research hotspot.
The driving chip belongs to one of the most important devices of the LED display screen, and can provide constant output current for the LED display screen. Based on the detection requirement for the driving chip, the real-time working temperature and the real-time working voltage of the driving chip need to be detected.
Disclosure of Invention
The embodiment of the invention provides a power supply detection circuit, a driving chip, a controller and an LED driving system, which are used for detecting the real-time working temperature or the real-time working voltage of the driving chip.
In order to solve the above problem, in a first aspect, an embodiment of the present invention discloses a power detection circuit, including:
the detection module is used for detecting the working temperature or the working voltage of the driving chip and outputting a first voltage value at a target working temperature or a target working voltage; the voltage output module outputs a corresponding second voltage value based on the currently gated selection signal; wherein, different selection signals correspond to different second voltage values; the comparator, the first input end connects the first voltage value, the second input end connects the second voltage value, the carry-out terminal outputs the comparative result of the first voltage value and second voltage value, in order to upgrade the state of the selective signal of the present strobe on the basis of the comparative result; under the condition that the current gated selection signal is kept in the updated state, the voltage output module continues to output a second voltage value based on the next gated selection signal in the configuration sequence until the difference value between the output second voltage value and the first voltage value meets the precision requirement, and the quantized value of the first voltage value is determined according to the target selection signal corresponding to the second voltage value meeting the precision requirement.
Optionally, the voltage output module includes: n-way selector and connected to drive chip for operationA constant current source between the power supply and the ground and n resistors R connected in series in sequence 1 ~R n (ii) a The constant current source provides the corrected accurate current; the N-path selector comprises N +1 data selection ends and a signal receiving end, wherein the N +1 data selection ends are connected with a plurality of connecting nodes between the working power supply of the driving chip and the ground in a one-to-one correspondence manner; wherein the plurality of connection nodes include R 1 ~R n Between any two adjacent resistors, R 1 A connection node with ground, and R n The connection node is connected with the working power supply of the driving chip; the N-path selector obtains a current gating selection signal based on the signal receiving end, determines a target data selection end according to the current gating selection signal, and outputs the voltage accessed by the target data selection end as a second voltage value.
Optionally, the voltage output module includes: first converting circuit and second converting circuit connected between driver chip working power supply and ground, wherein: the first conversion circuit can generate a third voltage value based on the lower data of the currently gated selection signal; the second conversion circuit can generate a fourth voltage value based on the high-order data of the currently-gated selection signal; the second conversion circuit is connected with the output end of the first conversion circuit to obtain a third voltage value, and can output a second voltage value based on the third voltage value and a fourth voltage value.
Optionally, the detection module includes a temperature detection unit and a voltage detection unit, wherein: the voltage output end of the temperature detection unit is connected with the first input end through a first enabling signal switch, and the temperature detection unit is used for detecting the working temperature of the driving chip and outputting a first voltage value at a target working temperature; the voltage output end of the voltage detection unit is connected with the first input end through a second enabling signal switch, and the voltage detection unit is used for detecting the working voltage of the driving chip and outputting a first voltage value under the target working voltage.
Optionally, the temperature detecting unit includes: the constant current source and the diode are connected in series between a working power supply of the driving chip and the ground, and a connecting node between the constant current source and the diode is connected with a voltage output end of the temperature detection unit; the constant current source provides the corrected accurate current; and a diode generating a voltage variation based on the precision current and the target operating temperature to generate a first voltage value at the target operating temperature at the connection node.
In a second aspect, an embodiment of the present invention further discloses a driver chip, where the driver chip is provided with the power detection circuit according to the first aspect of the embodiment of the present invention.
In a third aspect, an embodiment of the present invention further discloses a controller, where the controller is connected to the driving chip of the second aspect of the embodiment of the present invention, and the controller is configured to: receiving a first quantized value and a second quantized value which are sequentially transmitted by a driving chip, and calculating and outputting the real-time working temperature of the driving chip based on the first quantized value, the second quantized value and the reference working temperature of the driving chip; or
Receiving a third quantized value and a fourth quantized value which are sequentially transmitted by the driving chip, and calculating and outputting a real-time working voltage of the driving chip based on the third quantized value, the fourth quantized value and a reference working voltage of the driving chip;
the driving chip is provided with a temperature detection mode and a voltage detection mode;
when the controller controls the driving chip to be in a temperature detection mode, the first quantized value is a quantized value of a first voltage value at a reference working temperature, and the second quantized value is a quantized value of the first voltage value at a real-time working temperature;
when the controller controls the driving chip to be in the voltage detection mode, the third quantized value is the quantized value of the first voltage value under the reference working voltage, and the fourth quantized value is the quantized value of the first voltage value under the real-time working voltage.
Optionally, the controller is configured with a first calculation logic, so as to calculate a real-time operating temperature of the driving chip based on the first quantized value, the second quantized value and the reference operating temperature under the first calculation logic; the first computation logic includes: t = T 0 + (D0-DT) (Q/P) (1); wherein T is the real-time working temperature, T 0 For the reference operating temperature, D0 is a first quantized value of a first voltage value at the reference operating temperature, DT is a first voltage value at the real-time operating temperatureA second quantized value of the voltage value, P representing a voltage change amount per 1 degree celsius change in temperature; q represents a voltage change amount per 1-code value change of the voltage output block in the driver chip, and P, Q is an integer.
Optionally, the controller is configured with a second calculation logic, so as to calculate a real-time working voltage of the driving chip based on the third quantized value, the fourth quantized value and the reference working voltage under the second calculation logic; the second computational logic includes: VDD = VDD _ DET × DV/D1 (2); VDD is the real-time operating voltage, VDD _ DET is the first voltage value under the reference operating voltage, DV is the fourth quantized value of the first voltage value under the real-time operating voltage, and D1 is the third quantized value of the first voltage value under the reference operating voltage.
In a fourth aspect, the embodiment of the present invention further discloses an LED driving system, which includes a controller and at least one driving chip, where the controller and the driving chip are connected to each other, the driving chip is the driving chip according to the second aspect of the embodiment of the present invention, and the controller is the controller according to the third aspect of the embodiment of the present invention;
the controller sends a first enabling signal to the driving chip so that the driving chip is switched to a temperature detection mode; in the temperature detection mode, the driving chip outputs a first quantized value of a first voltage value at a reference working temperature to the controller based on the reference working temperature of the driving chip configured in advance; outputting a second quantized value of the first voltage value at the real-time working temperature to the controller based on the first voltage value of the currently detected driving chip at the real-time working temperature; the controller calculates and outputs a real-time working temperature based on the first quantized value, the second quantized value and the reference working temperature;
or the like, or a combination thereof,
the controller sends a second enabling signal to the driving chip so that the driving chip is switched to a voltage detection mode; in the voltage detection mode, the driving chip outputs a third quantized value of the first voltage value under the reference working voltage to the controller based on the reference working voltage of the driving chip configured in advance; outputting a fourth quantization value of the first voltage value under the real-time working voltage to the controller based on the first voltage value of the currently detected driving chip under the real-time working voltage; the controller calculates and outputs a real-time operating voltage based on the third quantized value, the fourth quantized value, and the reference operating voltage.
The embodiment of the invention has the following advantages:
the embodiment of the invention can effectively detect the working temperature or the working voltage of the driving chip. The power supply detection circuit comprises a detection module, a voltage output module and a comparator, and under the combined action of the voltage output module and the comparator, a first voltage value at a target working temperature or a target working voltage output by the detection module can be quantized, so that the real-time working temperature or the real-time working temperature of the driving chip can be obtained and output; when the detection module detects the working temperature of the LED driving chip, the voltage output module and the comparator can respectively quantize a first voltage value at the reference working temperature and a first voltage value at the real-time working temperature, and then the real-time working temperature of the driving chip can be obtained and output according to the reference working temperature, the first quantized value of the first voltage value at the reference working temperature and the second quantized value of the first voltage value at the real-time working temperature; when the detection module detects the working voltage of the LED driving chip, the voltage output module and the comparator can respectively quantize the first voltage value under the reference working voltage and the first voltage value under the real-time working voltage, and then the real-time working voltage of the driving chip can be obtained and output according to the reference working voltage, the third quantized value of the first voltage value under the reference working voltage and the fourth quantized value of the first voltage value under the real-time working voltage.
The embodiment of the invention not only can effectively detect the working temperature or the working voltage of the LED driving chip, but also can multiplex the voltage output module and the comparator due to the detection of the real-time working temperature and the real-time working voltage, can reduce the area of the power supply detection circuit, can reduce the area of the LED driving chip, and saves the circuit design and manufacturing cost.
Drawings
FIG. 1 is a circuit diagram of a power detection circuit according to an embodiment of the invention;
FIG. 2 is a circuit diagram of a power detection circuit according to another embodiment of the present invention;
FIG. 3 is a circuit diagram of a voltage output module according to an embodiment of the present invention;
FIG. 4 is a circuit schematic of a voltage output module according to another embodiment of the present invention;
FIG. 5 is a circuit diagram of the voltage output module shown in FIG. 4 according to an embodiment of the present invention;
FIG. 6 is a timing diagram of a temperature detection/voltage detection process according to one embodiment of the present invention;
FIG. 7 is a diagram of a driver chip according to an embodiment of the invention;
fig. 8 is a circuit diagram of an LED driving system according to an embodiment of the invention.
Description of reference numerals:
1-an LED driving chip, 2-a controller;
10-a power supply detection circuit, 100-a detection module, 200-a voltage output module, 300-a comparator;
101-temperature detection unit, 102-voltage detection unit, 103-first enable signal switch, 104-second enable signal switch;
201-N route selector, 202-constant current source, 203-connection node; 204-a first conversion circuit, 2041-a fixed resistor, 2042-a gating switch, 2043-a first current source; 205-second switching circuit, 2051-series circuit, 2052-second current source, 2053-multiplexer.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be obtained by a person skilled in the art without making any creative effort based on the embodiments in the present invention, belong to the protection scope of the present invention.
Referring to fig. 1, a circuit diagram of a power detection circuit according to an embodiment of the present invention is shown, the power detection circuit includes: the driving circuit comprises a detection module 100, a voltage output module 200 and a comparator 300, wherein the detection module 100 is used for detecting the working temperature or the working voltage of the driving chip and outputting a first voltage value at a target working temperature or a target working voltage; the voltage output module 200 is configured to output a corresponding second voltage value based on the currently gated selection signal; wherein, different selection signals correspond to different second voltage values; a first input terminal of the comparator 300 is connected to the first voltage value, a second input terminal of the comparator 300 is connected to the second voltage value, and an output terminal of the comparator 300 outputs a comparison result of the first voltage value and the second voltage value to update a state of the currently gated selection signal based on the comparison result; under the condition that the current gated selection signal is kept in the updated state, the voltage output module 200 continues to output the second voltage value based on the next gated selection signal in the configuration sequence until the difference between the output second voltage value and the first voltage value meets the accuracy requirement, so as to determine the quantized value of the first voltage value according to the target selection signal corresponding to the second voltage value meeting the accuracy requirement.
In an embodiment, the detection module 100 has two functions, that is, detecting the operating temperature of the driving chip, and detecting the operating voltage of the driving chip, and can output the corresponding detection result in the form of a voltage value. When the operating temperature of the driving chip is detected, the detection module 100 can output a first voltage value corresponding to the target operating temperature. Alternatively, the target operating temperature may be a reference operating temperature or a real-time operating temperature. When detecting the operating voltage of the driving chip, the detection module 100 can output a first voltage value corresponding to the target operating voltage, where the first voltage value may be understood as a voltage sampling value of the target operating voltage. Alternatively, the target operating voltage may be a reference operating voltage or a real-time operating voltage. The driving chip can be an LED driving chip.
It should be noted that, although the first voltage value appears when the operating temperature and the operating voltage of the driving chip are detected, the first voltage value at the target operating temperature and the first voltage value at the target operating voltage are not necessarily the same, and the first voltage value is only a symbol name and is distinguished from the second voltage value output by the voltage output module 200. In other words, the detection module 100 can only output one first voltage value at the same time. When the detection module 100 detects the operating temperature of the driving chip, the first voltage value is a voltage value corresponding to the target operating temperature. Further, when the target operating temperature is a reference operating temperature, the first voltage value is a voltage value corresponding to the reference operating temperature; when the target working temperature is the real-time working temperature, the first voltage value is a voltage value corresponding to the real-time working temperature. When the detection module 100 detects the operating voltage of the driving chip, the first voltage value is a voltage value corresponding to the target operating voltage. Further, when the target working voltage is a reference working voltage, the first voltage value is a voltage value corresponding to the reference working voltage; when the target working voltage is the real-time working voltage, the first voltage value is a voltage value corresponding to the real-time working voltage.
In order to determine the real-time operating temperature or the real-time operating voltage of the driving chip, the present embodiment employs the voltage output module 200 and the comparator 300 to quantize the first voltage value at the target operating temperature or the target operating voltage, and calculates the quantized value and the reference operating temperature or the reference operating voltage as known quantities. First, the voltage output module 200 and the comparator 300 quantize the first voltage value at the reference operating temperature to obtain a first quantized value, and then the voltage output module 200 and the comparator 300 quantize the first voltage value at the real-time operating temperature to obtain a second quantized value. Therefore, the real-time working temperature of the driving chip can be determined according to the reference working temperature, the first quantized value of the first voltage value at the reference working temperature and the second quantized value of the first voltage value at the real-time working temperature. Similarly, the first voltage value under the reference working voltage and the first voltage value under the real-time working voltage can be quantized by the voltage output module 200 and the comparator 300, respectively, and the real-time working voltage of the driving chip can be determined according to the reference working voltage, the third quantized value of the first voltage value under the reference working voltage, and the fourth quantized value of the first voltage value under the real-time working voltage. The power detection circuit of this embodiment can not only effectively detect driver chip's operating temperature or operating voltage, still can multiplex voltage output module 200 and comparator 300 because of real-time operating temperature and real-time operating voltage's detection, can reduce power detection circuit's area, practices thrift circuit design, manufacturing cost, and the power detection circuit of this embodiment has that detection stability is strong, detects the precision height, advantages such as circuit structure is simple.
Next, how the voltage output module 200 and the comparator 300 quantize the first voltage value at the target operating temperature or the target operating voltage will be described by taking detection of the operating temperature or the operating voltage of the LED driving chip having the common cathode structure as shown in fig. 1 as an example.
The voltage output module 200 has at least a signal receiving terminal, which can obtain the currently gated selection signal from the signal selecting terminal and then output the second voltage value corresponding to the gated selection signal. In the voltage output module 200, different selection signals correspond to different second voltage values. In an embodiment, an order of the currently gated selection signals may be pre-configured, and the second voltage values corresponding to the selection signals are compared with the first voltage values bit by bit from high to low based on the configuration order. For example, an N-bit selection signal set is pre-configured, the N-bit selection signal set includes a plurality of selection signals that are gated one by one from a high bit to a low bit in a configuration order, and N is an integer greater than or equal to 1. Gating one by one from high to low in the configuration order may be understood as sequentially configuring the N-bit selection signal set S [ (N-1):0] with each bit being 1, that is, configuring S [ N-1] =1 first, and then configuring S [ N-2] =1 and S [ N-3] =1 in sequence. And sequentially configuring the bits of the N-bit selection signal set S [ (N-1):0] as 1 respectively, wherein the corresponding second voltage value is larger and smaller, so that the second voltage value with the difference value meeting the precision requirement with the first voltage value can be found out orderly and effectively.
The comparator 300 may have a first input terminal coupled to the first voltage value, a second input terminal coupled to the second voltage value, and an output terminal for outputting a comparison result between the first voltage value and the second voltage value. For example, in a cascode driver chip, the first input terminal is a non-inverting input terminal of the comparator 300, the second input terminal is an inverting input terminal of the comparator 300, and if the second voltage value is smaller than the first voltage value, the comparison result is output as a high level, i.e., a value "1"; if the second voltage value is greater than the first voltage value, the comparison result is output as a low level, i.e., a value of "0".
If the comparison result is that the second voltage value is greater than or less than the first voltage value, the state of the currently gated selection signal of the voltage output module 200 may be updated based on the comparison result, and then the next selection signal in the configuration sequence is gated and a corresponding second voltage value is output, such that the difference between the second voltage value and the first voltage value is gradually reduced. If the second voltage value is greater than the first voltage value, after the voltage output module 200 updates the state of the currently gated selection signal, the selection signal of the next gating should be selected toward the selection signal corresponding to the smaller second voltage value; if the second voltage value is smaller than the first voltage value, the voltage output module 200 updates the state of the currently gated selection signal, and then the selection signal of the next gate should be selected toward the selection signal corresponding to the larger second voltage value. Until the difference between the second voltage value output by the voltage output module 200 and the first voltage value meets the accuracy requirement, the quantization value of the first voltage value may be determined according to the target selection signal corresponding to the second voltage value meeting the accuracy requirement.
The updating of the state of the currently gated selection signal of the voltage output module 200 based on the comparison result can be understood as replacing the bit value of the currently gated selection signal in the N-bit selection signal set S [ (N-1):0] with the value corresponding to the comparison result. For example, in the 8-bit selection signal set S [7:0], the selection signal S [7] =1 is gated first, the corresponding binary value is 10000000, if the comparison result is that the second voltage value is greater than the first voltage value, the second voltage value needs to be decreased continuously, in fig. 1, the non-inverting input of the comparator 300 is connected to the first voltage value, the inverting input is connected to the second voltage value, at this time, the comparator 300 will output a low level, i.e., a value "0", based on the comparison result, the value "0" updates S [7] =0, i.e., the "1" in the binary "10000000" becomes "0", in the subsequent comparison, S [7] =0 is maintained all the time, the next gated selection signal in the configuration order is S [6] =1, and the corresponding binary value is 01000000; if the comparison result is that the second voltage value is still greater than the first voltage value, the second voltage value needs to be continuously decreased, S [6] =0 is updated based on the comparison result value "0", in the subsequent comparison, S [6] =0 is always kept, the selection signal of the next strobe in the configuration sequence is S [5] =1, the binary value corresponding to the selection signal is represented as 00100000.. until a target selection signal corresponding to the second voltage value, of which the difference value with the first voltage value meets the precision requirement, is obtained, and the binary value corresponding to the target selection signal can be used as the quantized value of the first voltage value.
For example, in the 8-bit selection signal set S [7:0], S [7] =1 is first configured, and the corresponding binary value is represented as 10000000, and if the comparison result indicates that the second voltage value is smaller than the first voltage value, the second voltage value needs to be increased continuously, since under the cascode driving chip, the non-inverting input terminal of the comparator 300 is connected to the first voltage value, and the inverting input terminal is connected to the second voltage value, at this time, the comparator 300 will output a high level, i.e. a value "1". Based on the comparison result value "1", update S [7] =1, that is, "1" in 10000000 is still updated to "1", in the subsequent comparison, S [7] =1 is always maintained, the selection signal of the next strobe in the configuration order is S [6] =1, and the corresponding binary value thereof is 11000000; if the comparison result is that the second voltage value is still smaller than the first voltage value, the second voltage value needs to be increased continuously, S [6] =1 is updated based on the comparison result value "1", in the subsequent comparison, S [6] =1 is always kept, the selection signal of the next strobe in the configuration order is S [5] =1, the binary value corresponding to the selection signal is represented as 11100000.
Based on the method, the invention can obtain a first quantized value of the first voltage value at the reference working temperature and a second quantized value of the first voltage value at the real-time working temperature; or a third quantized value of the first voltage value under the reference working voltage and a fourth quantized value of the first voltage value under the real-time working voltage.
Similarly, referring to fig. 2, a circuit diagram of a power detection circuit according to another embodiment of the invention is shown, as shown in fig. 2, under a common positive driver chip, the scheme provided by the invention is also applicable, except that when the first input terminal of the comparator 300 is the inverting input terminal of the comparator 300 and the second input terminal is the non-inverting input terminal of the comparator 300, if the second voltage value is smaller than the first voltage value, the comparison result is output as a low level, i.e. a value "0"; if the second voltage value is greater than the first voltage value, the comparison result is output as a high level, i.e., a value of "1". The foregoing description is referred to for the implementation logic, and will not be repeated herein.
Next, some possible circuit configurations of the voltage output module 200 of the present invention will be explained.
In an embodiment of the present invention, the voltage output module 200 may include: an N-way selector 201, a constant current source 202 connected between the working power supply of the LED driving chip and the ground, and N resistors R connected in series in sequence 1 ~R n (ii) a The constant current source 202 is used for providing a trimmed precise current; wherein: the N-path selector 201 comprises N +1 data selection ends and a signal receiving end, wherein the N +1 data selection ends are connected with a plurality of connecting nodes 203 between the working power supply of the LED driving chip and the ground in a one-to-one correspondence manner; wherein the plurality of connection nodes 203 comprise R 1 ~R n Between any two adjacent resistors, and a connection node 203, R 1 A connection node 203 with ground, and R n A connection node 203 connected with the LED driving chip working power supply; the N-way selector 201 obtains a currently gated selection signal based on the signal receiving terminal, determines a target data selection terminal according to the currently gated selection signal, and outputs a voltage accessed by the target data selection terminal as a second voltage value.
Referring to fig. 3, a circuit diagram of a voltage output module 200 according to an embodiment of the invention is shown, and the voltage output module 200 shown in fig. 3 is based on a cascode chip structure. In this embodiment, the voltage output module 200 can be implemented in two ways:
the first method is as follows: the plurality of selection signals have a non-fixed one-to-one correspondence relationship with voltages accessed by the n +1 data selection terminals. Common cathode N-bit voltage output module 200 middle powerResistance R 1 ~R n The resistances are all the same, and the voltage drop across each resistor is the same, assuming Vr0 (obtained by multiplying the precision current by a single resistor), the second output voltage V2= S × Vr0, and S represents the selected number of voltage drops. First gating the select signal S [ N-1]]=1, the selection signal corresponds to a data selection terminal connected to a middle value between the voltages VDD and GND at the operating power supply of the LED driving chip, and the second voltage value V2=2 N-1 Vr 0. If the first voltage value V1>The second voltage value V2, the second voltage value V2 needs to be increased continuously, the comparator 300 outputs 1, and S [ N-1] is compared later]Always equal to 1, and then continues to gate the selection signal S [ N-2] according to the configuration sequence]=1, the selection signal corresponds to access 2 N-1 Vr0 and VDD, when the second voltage value V2= (2) N-1 +2 N-2 ) Vr 0; if the first voltage value V1>The second voltage V2, V2, is continuously increased, and then the second voltage is searched according to the dichotomy (2) N-1 +2 N-2 ) The Vr0 and the VDD are centered until a second voltage value with the difference value meeting the accuracy requirement with the first voltage value is determined, and the quantized value of the first voltage value is determined according to a target selection signal corresponding to the second voltage value meeting the accuracy requirement.
The second method comprises the following steps: the plurality of selection signals and the voltages accessed by the n +1 data selection terminals have fixed one-to-one correspondence. For example, select signal S [ N-1]]When the signal is gated according to the signal value of =1, the corresponding data selection end is connected to the working power supply of the LED driving chip, and then the second voltage value V2 is represented by R 1 +R 2 ......R n The sum multiplied by the precision current, which may be equal to the operating voltage VDD, for example; select signal S [ N-2]]When the signal is gated by =1, the voltage connected to the corresponding data selection terminal is the accurate current (R) 1 +R 2 ......R n-1 ) The second voltage value V2 is the precision current (R) 1 +R 2 ......R n-1 ). Accordingly, select signal S [0]]When =1 is turned on, the corresponding data selection terminal is connected to GND, and the second voltage value V2 is 0. Based on the sequential selection method, the voltage output module 200 outputs the second voltage value in the range of 0 to VDD from large to small or from large to small based on the selection signals gated one by one in the configuration sequenceAnd outputting the voltage value from small to large until the difference value of the second voltage value and the first voltage value meets the precision requirement. Of course, this comparison is slower and the first is generally preferred.
Wherein the voltage output module shown in fig. 3 provides a series resistance R 1 ~R n The new arrangement mode can effectively reduce the occupied circuit area while ensuring the monotonicity of the circuit.
Referring to fig. 4, a schematic circuit diagram of a voltage output module 200 according to another embodiment of the present invention is shown, where the voltage output module 200 may include: the first conversion circuit 204 and the second conversion circuit 205 are connected between the working power supply of the LED driving chip and the ground, wherein: the first conversion circuit 204 can generate a third voltage value based on the lower data of the currently gated selection signal; the second conversion circuit 205 can generate a fourth voltage value based on the upper data of the currently strobed selection signal; the second converting circuit 205 is connected to the output terminal of the first converting circuit 204 to obtain a third voltage value, and can output a second voltage value based on the third voltage value and the fourth voltage value.
In this embodiment, the first conversion circuit 204 belongs to the idea of adjusting the current in the circuit to output voltage values of different magnitudes based on the fixed resistor 2041; the second converting circuit 205 belongs to the idea of fixing current and selectively connecting different numbers of resistors to output voltage values of different magnitudes. As shown in FIG. 5, a circuit schematic of the voltage output module 200 shown in FIG. 4 is shown; the first converting circuit 204 may include a fixed resistor 2041 and a plurality of parallel branches, each branch includes a gate switch 2042 and a first current source 2043 connected in series, each first current source 2043 is connected to a first end of the fixed resistor 2041, a second end of the fixed resistor 2041 is grounded, and each gate switch 2042 is connected to a working power supply of the LED driving chip. The gating switch 2042 can control the on/off of the branch in which the gating switch is located, that is, whether current flows out of the branch is controlled, the current flowing into the fixed resistor 2041 is the sum of the currents provided by the first current sources 2043 in all the closed branches, that is, the third voltage value is the product of the fixed resistor 2041 and the sum of the currents. Assuming that the selection signal is multilevel coded, the current values output by the first current sources respectively correspond to the weight value of each bit of the low-bit data one by one. For example, in the most common binary system, for the binary system selection signal, assuming that the lower data has a total of X bits, the weight values from the lower bit to the upper bit are 1, 2, and 4 … … 2X-1, so that the current values of the plurality of first current sources 2043 are I, 2I, and 4I … … (2X-1) I in sequence, and the on/off of the branch where the first current source is located is controlled by the gating switch 2042.
The second converting circuit 205 includes a series circuit 2051 composed of a plurality of serially connected voltage dividing resistors, a second current source 2052 and a multiplexer 2053, a first end of the series circuit 2051 is connected to a first end of the fixed resistor 2041 of the first converting circuit 204, a second end is used for outputting a second voltage value V2, and the multiplexer 2053MUX is MUX 2N-X -1 a second current source 2052 and a series circuit 2051 for high data VS based on a selection signal<(N-1):X>The number of resistors in series with the second current source 2052 is selected. The current value output by the second current source 2052 corresponds to the weight value of the lowest bit of the high-order data. For example, assuming that the binary selection signal is 10111101, the lower data is 1101, the upper data is 1011, the lowest bit of the upper data corresponds to the fifth bit, and the weight of the fifth bit of the binary selection signal is 16, the current value output by the second current source 2052 may be 16I. Assuming that the selection signal is 10111101, the low data is 1101, the high data is 1011, and the high data is converted to decimal 11, the multiplexer 2053 may select 11 resistors to be connected in series with the second current source 2052, and the fourth voltage value may be 11R × 16I.
In the voltage output module 200 of the common cathode structure shown in fig. 5, the second voltage value V2= the third voltage value + the fourth voltage value. In the common-anode configuration, the voltage output module 200 outputs the second voltage value V2 ═ VDD- (V1+ V2). Compared with the voltage output module 200 shown in fig. 3, the voltage output module 200 provided by the embodiment of the invention can avoid the problem of large circuit occupation area when the number of resistors and data selection ends is large in an exponential manner, and can reduce the circuit area while ensuring the monotonicity of the circuit.
It should be noted that the low-order data in this embodiment is relative to the high-order data, such as an 8-bit binary selection signal, and from left to right, the left 4 bits may be used as the high-order data, and the right 4 bits may be used as the low-order data; the left 6 bits may be high data and the right 2 bits may be low data. The present embodiment is not limited to a specific method for dividing the high-order data and the low-order data of the selection signal.
In an embodiment of the present invention, as shown in fig. 1 and fig. 2, the detection module 100 includes a temperature detection unit 101 and a voltage detection unit 102, wherein: the voltage output end of the temperature detection unit 101 is connected with the first input end through a first enable signal switch 103, and the temperature detection unit 101 is used for detecting the working temperature of the LED driving chip and outputting a first voltage value at a target working temperature; the voltage output end of the voltage detection unit 102 is connected to the first input end through the second enable signal switch 104, and the voltage detection unit 102 is configured to detect a working voltage of the LED driving chip and output a first voltage value under a target working voltage. In this embodiment, since the temperature detecting unit 101 and the voltage detecting unit 102 are connected to the first input terminal of the comparator 300, the detecting module 100 can only provide one voltage value to the comparator 300 at the same time, i.e. the first voltage value at the target operating temperature or the first voltage value at the target operating voltage. The conduction between the temperature detection unit 101 and the comparator 300 is controlled by a first enable signal switch 103 therebetween, and the conduction between the voltage detection unit 102 and the comparator 300 is controlled by a second enable signal switch 104 therebetween. Whether the first enable signal switch 103 and the second enable signal switch 104 are closed or not can be configured in advance by the system, that is, different enable signal switches are driven to be opened in different time periods; of course, whether the first enable signal switch 103 and the second enable signal switch 104 are closed or not may be controlled by a controller or the like. As shown in fig. 1, if the enable signal VTEMP _ DET _ EN =1, the first enable signal switch 103 is turned on, the voltage output terminal of the temperature detection unit 101 outputs the first voltage value at the target operating temperature to the first input terminal of the comparator 300, and the power detection circuit starts the temperature detection function; when the enable signal VDD _ DET _ EN =1, the second enable signal switch 104 is turned on, the voltage output terminal of the voltage detection unit 102 outputs the first voltage value at the target operating voltage to the first input terminal of the comparator 300, and the power detection circuit starts the voltage detection function. The specific structure of the enable signal switch may be in various ways, and the embodiment of the present invention is not limited herein. Similarly, if the enable signal VTEMP _ DET _ EN =0, the first enable signal switch 103 is turned off, and the power detection circuit turns off the temperature detection function; when the enable signal VDD _ DET _ EN =0, the second enable signal switch 104 is turned off, and the power detection circuit turns off the voltage detection function.
In an embodiment of the present invention, as shown in fig. 1 and 2, the temperature detecting unit 101 may include: the constant current source and the diode are connected in series between the working power supply of the LED driving chip and the ground, and a connecting node between the constant current source and the diode is connected with the voltage output end of the temperature detection unit 101; the constant current source provides the corrected accurate current; the diode generates a voltage change based on the precision current and the target operating temperature to generate a first voltage value at the connection node at the target operating temperature. In an embodiment, the temperature detection unit 101 may obtain the voltage VTEMP at the target operating temperature (when the first voltage value V1= VTEMP) by using the negative temperature characteristic of the pn junction voltage of the diode under the effect of the precise current. According to the temperature characteristics of the diode, assuming that the reference operating temperature =25 degrees celsius and VTEMP = V25 (volts), then the real-time operating temperature is T degrees celsius, (VTEMP-V25)/(T-25) = k, k is the negative temperature coefficient of the diode, k is a negative constant, k represents how much (negative) volts VTEMP decreases for every 1 degree celsius decrease in temperature T. Since the constant current source of the present embodiment can provide the adjusted precise current, the voltage variation value generated by the diode is more precise, so that the present embodiment can generate the precise first voltage value at the target operating temperature at the connection node between the constant current source and the diode.
As shown in fig. 1, in the common-cathode structure, the constant current source is connected to the operating power supply of the LED driving chip, the diode is grounded, and the first voltage value V1 at the target operating temperature generated at the connection node is the voltage value of the diode. As shown in fig. 2, in the common anode configuration, the diode is connected to the LED driving chip operating power supply, and the constant current source is grounded, and the first voltage value V1 at the target operating temperature generated at the connection node is VDD minus the voltage value of the diode. The VDD may be an operating voltage of the LED driving chip.
Next, taking the structure of the cascode driving chip as an example, the temperature detection process of the present invention will be described by using a dichotomy method based on the voltage output module 200 shown in fig. 3.
Configuring an enable signal VTEMP _ DET _ EN =1, the first enable signal switch 103 being closed, gating the temperature detection unit 101, the temperature detection unit 101 outputting the first voltage value V1= VTEMP to the first input terminal V _ DET of the comparator 300, enabling the temperature detection function;
assume a reference operating temperature of 25 0 C, obtaining 25 by the temperature detection unit 101 using the negative temperature characteristic of the pn junction voltage of the diode 0 VTEMP = V25 at C; wherein, V25 can be output from the test port through the chip test mode.
At a temperature of 25 deg.C 0 C, a selection signal set S [ (N-1): 0) is sequentially arranged]Each bit is 1, samples DET _ OUT with a certain time delay (for example, M CLK periods, M is an integer), and let S [ (N-1):0]Respectively equal to the sampled DET _ OUT, finally 25 are obtained 0 C is N-bit S [ (N-1): 0)]The value D25. The process is realized as follows:
resistor R in voltage output module 200 1 ~R n The resistance values are the same, and the voltage drop across each resistor is the same, which is assumed to be Vr 0. And Vr0 and k satisfy P x Vr0= Q x k, wherein P, Q is an integer; the voltage output module 200 outputs the second voltage value V2= S × Vr 0. First gating select signal S [ N-1]]=1, the second voltage value V2=2 N-1 Vr0, the second voltage value at this time is the midpoint value of the output range of the voltage output module 200. If VTEMP>V2, i.e. V25>V2, then V2 needs to be increased further, at which time DET _ OUT of comparator 300 outputs 1, S [ N-1] in the following comparison]Always equal to 1, S is greater than the current S value in the subsequent comparison, the larger S is, the larger V2 is, the like, and S [ (N-1):0 is configured in sequence]Each bit is 1 respectively until the difference value between the V2 and the V25 meets the precision requirement, and at the moment, the quantized value D25 of the V25 is determined according to the target selection signal corresponding to the second voltage value V2 meeting the precision requirement. If VTEMP<V2, i.e. V25<V2, then V2 needs to be decreased further, at which point DET _ OUT of comparator 300 outputs 0, which in the following comparison will be S [ N-1]]Always equal to 0, S is smaller than the current S value in the subsequent comparison, the smaller S is, the smaller V2 is, the requirement is met, and the like, S [ (N-1):0 is configured in sequence]Each bit is 1 respectively until the difference value of V2 and V25 meets the precision requirement, and a quantized value D25 of V25 is determined. The system configuration VTEMP _ DET _ EN is 0, turning off the temperature detection function.
Through the above process, the first quantized value D25 of the first voltage value at 25 degrees celsius is obtained. Similarly, when the real-time working temperature T is to be measured, the system can set VTEMP _ DET _ EN to 1 and start the temperature detection function; sequentially configuring selection signal set S [ (N-1): 0)]Each bit is 1, samples DET _ OUT are taken at certain time delays (for example, M CLK periods, M is an integer), and S [ (N-1):0]Are respectively equal to the sampled DET _ OUT, and finally T is obtained 0 C is N-bit S [ (N-1): 0)]The value DT, DT is a second quantized value of the first voltage value at the real-time operating temperature. The obtaining process of DT can refer to the obtaining process of D25, and is not described in detail herein.
After obtaining D25, D25 may be stored and transmitted to the controller for recording, and after DT is obtained, DT is transmitted to the controller for recording. D25 may also be transmitted to the controller for recording along with DT after D25 and DT are obtained. The real-time working temperature can be calculated according to D25, DT and the reference working temperature (25 ℃), and the calculation process of the real-time working temperature is realized at the controller side, which is described in detail later and is not described herein.
In an embodiment of the present invention, as shown in fig. 1 and 2, the voltage detection unit 102 may include: at least two resistors connected in series between the driving chip working power supply and the ground, wherein any connection point between the at least two resistors is connected with the voltage output end of the voltage detection unit 102. In this embodiment, the driving chip working power supply may provide a working voltage of the LED driving chip, at least two resistors connected in series between the driving chip working power supply and the ground constitute a voltage dividing circuit, and a voltage value at any connection point between the at least two resistors may be used as a voltage sampling value of the target working voltage, that is, a first voltage value under the target working voltage.
Next, taking the structure of the cascode driving chip as an example, the voltage detection process of the present invention will be described by using a dichotomy method based on the voltage output module 200 shown in fig. 3.
Configuring an enable signal VDD _ DET _ EN =1, closing the second enable signal switch 104, gating the voltage detection unit 102, outputting VDD _ DET to the first input terminal V _ DET of the comparator 300 by the voltage detection unit 102, and enabling a voltage detection function;
the voltage detection unit 102 divides the power supply voltage VDD equally by two identical resistors R, and the first voltage value V1= VDD _ DET = VDD/2 at the reference operating voltage; meanwhile, a chip test mode is utilized to output VDD _ DET through a test port;
resistor R in voltage output module 200 1 ~R n The resistance values are the same, and the voltage drop across each resistor is the same, which is assumed to be Vr 0. The voltage output module 200 outputs the second voltage value V2= S × Vr 0. First gating the select signal S [ N-1]]=1, the second voltage value V2=2 N-1 Vr0, the second voltage value at this time is the midpoint value of the output range of the voltage output module 200. If the first voltage value VDD _ DET under the reference working voltage>V2, then V2 needs to be increased further, at which point comparator 300 outputs 1, and in the following comparison S [ N-1]]And if the S value is always equal to 1, the S value is larger than the current S value in the subsequent comparison, the larger the S value is, the larger V2 is, the requirements are met until the difference value between V2 and the first voltage value VDD _ DET under the reference working voltage meets the accuracy requirement, and at the moment, the quantized value D1 of the first voltage value VDD _ DET under the reference working voltage is determined according to the target selection signal corresponding to the second voltage value V2 meeting the accuracy requirement. If VDD _ DET<V2, then V2 needs to be decreased further, at which point comparator 300 outputs 0, and in the following comparison, S [ N-1]]If the S value is always equal to 0, S is smaller than the current S value in subsequent comparison, and the smaller S is, the smaller V2 is, so that the requirement is met; by analogy, S [ (N-1): 0) is configured in sequence]Each bit is 1 respectively until the difference between V2 and the first voltage value VDD _ DET at the reference operating voltage satisfies the accuracy requirement, and a quantized value D1 of the first voltage value VDD _ DET at the reference operating voltage is determined. The system configures VDD _ DET _ EN to be 0, and turns off the voltage detection function.
Through the above process, the third quantized value D1 of the first voltage value at the reference operating voltage is obtained. Similarly, when the real-time working voltage is measured, the system sets VDD _ DET _ EN to 1, and starts the voltage detection function; sequentially configuring a selection signal set S [ (N-1):0] with each bit being 1, sampling DET _ OUT at certain time delay (for example, M CLK periods, M being an integer), and making S [ (N-1):0] be equal to the sampled DET _ OUT respectively, and finally obtaining an N-bit S [ (N-1):0] value DV corresponding to a first voltage value V1 under the real-time working voltage; and a fourth quantized value of the first voltage value at the DV real-time operating voltage. The DV acquisition process can refer to the acquisition process of D0, which is not described herein.
After obtaining D0, D0 may be stored and transmitted to the controller for recording first, and after obtaining DV, the DV may be transmitted to the controller for recording. After obtaining D0 and DV, D0 can also be transmitted to the controller for recording together with DV. The real-time operating voltage can be calculated according to D0, DV and the first voltage value VDD _ DET under the reference operating voltage, and the calculation process of the real-time operating voltage is implemented at the controller side, which is described in detail later and will not be described herein.
Referring to fig. 6, a timing diagram of the temperature detection/voltage detection process of an embodiment of the present invention is shown. Description of the sequence:
1) a-b, c-d, e-f, g-h are M DCLK periods used for analog signal establishment;
2) b-c, f-g are time for the output end DET _ OUT of the digital sampling comparator and logic operation;
3) h-i is the time for storing the 10-bit VF _ AVE [9:0] and returning the time to the controller; wherein VF _ AVE [9:0] denotes S [ (N-1):0 ];
4) i to: ending temperature/voltage detection, releasing the occupation of VF _ AVE [9:0], and reconnecting the VF _ AVE [9:0] to the actually calculated VF mean value VF _ AVE [9:0 ];
5) VDD _ DET _ EN and VTEMP _ DET _ EN cannot be high at the same time.
As can be seen from the timing diagram, in the process of comparing the second voltage value with the first voltage value, the power detection circuit of the present invention updates the state of the currently-gated selection signal according to the comparison result between the first voltage value and the second voltage value output from the output terminal DET _ OUT of the comparator 300, and in the following comparison, keeps the gating signal in the updated state all the time. The "state holding" in the timing chart indicates a bit value held by the currently gated select signal based on the comparison result output by DET _ OUT, i.e., the currently gated select signal is held in the updated state.
Based on the same inventive concept, the embodiment of the present invention further discloses an LED driving chip 1, and referring to fig. 7, a schematic diagram of the LED driving chip 1 according to the embodiment of the present invention is shown, and the LED driving chip 1 is provided with a power detection circuit 10 according to the embodiment of the present invention. The power detection circuit 10 can detect the operating temperature or the operating voltage of the LED driving chip 1, and can obtain a quantized value of the first voltage value at the target operating temperature of the LED driving chip 1, or obtain a quantized value of the first voltage value at the target operating voltage of the LED driving chip 1. The LED driving chip 1 has a storage and transmission function, and can store or transmit the quantized value of the first voltage value at the target operating temperature to a controller in the LED driving system, or store or transmit the quantized value of the first voltage value at the target operating voltage to the controller in the LED driving system, so that the controller can calculate the real-time operating temperature or the real-time operating voltage of the LED driving chip 1.
Based on the same inventive concept, the embodiment of the present invention also discloses a controller, which can be connected with the LED driving chip 1 according to the embodiment of the present invention, and is configured to: receiving a first quantized value and a second quantized value which are sequentially transmitted by the LED driving chip 1, and calculating and outputting the real-time working temperature of the LED driving chip 1 based on the first quantized value, the second quantized value and the reference working temperature of the LED driving chip 1; or receiving a third quantized value and a fourth quantized value which are sequentially transmitted by the driving chip, and calculating and outputting a real-time working voltage of the driving chip based on the third quantized value, the fourth quantized value and a reference working voltage of the driving chip; the LED driving chip 1 is configured with a temperature detection mode and a voltage detection mode; when the controller controls the LED driving chip 1 to be in the temperature detection mode, the first quantized value is a quantized value of a first voltage value at a reference working temperature, and the second quantized value is a quantized value of the first voltage value at a real-time working temperature; when the controller controls the LED driving chip 1 to be in the voltage detection mode, the third quantized value is a quantized value of the first voltage value under the reference working voltage, and the fourth quantized value is a quantized value of the first voltage value under the real-time working voltage. In the embodiment of the present invention, the LED driving chip 1 may be in the temperature detection mode or the voltage detection mode by sending different enable signals by the controller. For the implementation of the first quantized value, the second quantized value, the third quantized value and the fourth quantized value, reference is made to the foregoing contents, which are not repeated herein. The reference working temperature or the reference working voltage of the LED driving chip 1 may be output from the test port by the LED driving chip 1 through a chip test mode and then transmitted to the controller.
In the embodiment of the present invention, the controller is configured with a first calculation logic, so that the real-time operating temperature of the LED driving chip 1 can be calculated based on the first quantized value, the second quantized value and the reference operating temperature under the first calculation logic; wherein the first computational logic includes: t = T 0 + (D0-DT) (Q/P) (1); wherein T is the real-time operating temperature, T 0 D0 is a first quantized value of the first voltage value at the reference working temperature, DT is a second quantized value of the first voltage value at the real-time working temperature, and P represents the voltage variation of 1 degree centigrade per temperature variation; q represents a voltage change amount per 1 code value change of the voltage output module 200 in the LED driving chip 1, and P, Q is an integer. In one example, equation (1) may be calculated according to equation (VTEMP-V25)/(T-25) = k, in combination with equation P × Vr0= Q × k, where VTEMP is the first voltage value at the real-time operating temperature, V25 is the first voltage value at 25 ℃, and k is the negative temperature coefficient of the diode. Specific examples are as follows: if the quantization accuracy Vr0= k of the voltage output module 200, P = Q, the real-time temperature may be T =25 by calculating equation (1) 0 C+(D25-DT)。
Of course, the controller is further configured with a second calculation logic, so as to calculate the real-time working voltage of the driving chip based on the third quantized value, the fourth quantized value and the reference working voltage under the second calculation logic; the second computational logic includes: VDD = VDD _ DET × DV/D1 (2); VDD is the real-time operating voltage, VDD _ DET is the first voltage value under the reference operating voltage, DV is the fourth quantized value of the first voltage value under the real-time operating voltage, and D0 is the third quantized value of the first voltage value under the reference operating voltage. In this embodiment, VDD _ DET is replaced by a quantization value, i.e., VDD _ DET = D0 Vr0, V = DV Vr0, and the two equations are divided to obtain equation (2).
Based on the same inventive concept, the embodiment of the present invention further discloses an LED driving system, and referring to fig. 8, a schematic circuit diagram of the LED driving system according to an embodiment of the present invention is shown, where the LED driving system includes a controller 2 and at least one LED driving chip 1 that are connected to each other, the LED driving chip 1 is the LED driving chip 1 according to the embodiment of the present invention, and the controller 2 is the controller 2 according to the embodiment of the present invention;
the controller 2 sends a first enabling signal to the LED driving chip 1 so as to switch the LED driving chip 1 to a temperature detection mode; in the temperature detection mode, the LED driving chip 1 outputs a first quantized value of a first voltage value at a reference operating temperature to the controller 2 based on the reference operating temperature of the LED driving chip 1 configured in advance; outputting a second quantized value of the first voltage value at the real-time working temperature to the controller 2 based on the currently detected first voltage value of the LED driving chip 1 at the real-time working temperature; the controller 2 calculates and outputs a real-time working temperature based on the first quantized value, the second quantized value and the reference working temperature;
or the like, or a combination thereof,
the controller 2 sends a second enabling signal to the LED driving chip 1 to switch the LED driving chip 1 to the voltage detection mode; in the voltage detection mode, the LED driving chip 1 outputs a third quantized value of the first voltage value under the reference working voltage to the controller 2 based on the reference working voltage of the LED driving chip 1 configured in advance; outputting a fourth quantized value of the first voltage value under the real-time working voltage to the controller 2 based on the currently detected first voltage value under the real-time working voltage of the LED driving chip 1; the controller 2 calculates and outputs a real-time operating voltage based on the third quantized value, the fourth quantized value, and the reference operating voltage.
For the specific implementation process of the embodiment of the present invention, reference is made to the foregoing contents, which are not repeated herein. The LED driving system not only can effectively detect the real-time working temperature and the real-time working voltage of the LED driving chip 1, but also can multiplex the voltage output module 200 and the comparator 300 due to the detection of the real-time working temperature and the real-time working voltage, can reduce the area of the LED driving chip 1, saves the circuit design and manufacturing cost, and has the advantages of strong detection stability, high detection precision, simple circuit structure and the like.
It should be noted that, in the present specification, the embodiments are all described in a progressive manner, each embodiment focuses on differences from other embodiments, and the same and similar parts among the embodiments may be referred to each other.
It should also be noted that, in this document, the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience in describing the present invention and simplifying the description, but do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present invention. Moreover, relational terms such as "first" and "second" are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions or should not be construed as indicating or implying relative importance. "and/or" means that either or both of them can be selected. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or terminal that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or terminal. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other identical elements in the process, method, article, or terminal equipment comprising the element.
The technical solutions provided by the present invention are described in detail above, and the principle and the embodiments of the present invention are explained in the present document by applying specific examples, and the descriptions of the above examples are only used to help understanding of the present invention, and the content of the present specification should not be construed as limiting the present invention. While various modifications of the described embodiments and applications will be apparent to those skilled in the art, it is not necessary or necessary to exhaustively enumerate all embodiments, and obvious variations or modifications thereof can be made without departing from the scope of the invention.

Claims (10)

1. A power supply detection circuit, comprising:
the detection module is used for detecting the working temperature or the working voltage of the driving chip and outputting a first voltage value at a target working temperature or a target working voltage;
the voltage output module outputs a corresponding second voltage value based on the currently gated selection signal; wherein, different selection signals correspond to different second voltage values;
a comparator, a first input end of which is connected with the first voltage value, a second input end of which is connected with the second voltage value, and an output end of which outputs the comparison result of the first voltage value and the second voltage value, so as to update the state of the selection signal which is currently gated based on the comparison result;
under the condition that the current gated selection signal is kept in the updated state, the voltage output module continues to output a second voltage value based on the next gated selection signal in the configuration sequence until the difference value between the output second voltage value and the first voltage value meets the precision requirement, so that the quantized value of the first voltage value is determined according to a target selection signal corresponding to the second voltage value meeting the precision requirement.
2. The power supply detection circuit of claim 1, wherein the voltage output module comprises: n-way selector, and working power supply and ground connected to the driving chipA constant current source and n resistors R connected in series in sequence 1 ~R n ；
The constant current source provides the corrected accurate current;
the N-path selector comprises N +1 data selection ends and a signal receiving end, and the N +1 data selection ends are correspondingly connected with a plurality of connecting nodes between the working power supply of the driving chip and the ground one by one; wherein the plurality of connection nodes comprise R 1 ~R n Between any two adjacent resistors, R 1 A connection node with ground, and R n The connection node is connected with the working power supply of the driving chip;
and the N-path selector acquires a currently gated selection signal based on the signal receiving end, determines a target data selection end according to the currently gated selection signal, and outputs the voltage accessed by the target data selection end as the second voltage value.
3. The power supply detection circuit of claim 1, wherein the voltage output module comprises: first converting circuit and second converting circuit connected between driver chip working power supply and ground, wherein:
the first conversion circuit can generate a third voltage value based on the lower data of the currently gated selection signal;
the second conversion circuit can generate a fourth voltage value based on the high-order data of the currently-gated selection signal;
the second conversion circuit is connected with the output end of the first conversion circuit to obtain the third voltage value, and can output the second voltage value based on the third voltage value and the fourth voltage value.
4. The power detection circuit of claim 1, wherein the detection module comprises a temperature detection unit and a voltage detection unit, wherein:
the voltage output end of the temperature detection unit is connected with the first input end through a first enable signal switch, and the temperature detection unit is used for detecting the working temperature of the driving chip and outputting a first voltage value at a target working temperature;
the voltage output end of the voltage detection unit is connected with the first input end through a second enabling signal switch, and the voltage detection unit is used for detecting the working voltage of the driving chip and outputting a first voltage value under a target working voltage.
5. The power supply detection circuit according to claim 4, wherein the temperature detection unit includes: the constant current source and the diode are connected in series between a working power supply of the driving chip and the ground, and a connecting node between the constant current source and the diode is connected with a voltage output end of the temperature detection unit; wherein, the first and the second end of the pipe are connected with each other,
the constant current source provides the corrected accurate current;
the diode generates a voltage change based on the precision current and the target operating temperature to generate a first voltage value at the connection node at the target operating temperature.
6. A driver chip provided with the power detection circuit according to any one of claims 1 to 5.
7. A controller connected with the driver chip of claim 6, the controller configured to:
receiving a first quantized value and a second quantized value which are sequentially transmitted by the driving chip, and calculating and outputting the real-time working temperature of the driving chip based on the first quantized value, the second quantized value and the reference working temperature of the driving chip; or
Receiving a third quantized value and a fourth quantized value which are sequentially transmitted by the driving chip, and calculating and outputting a real-time working voltage of the driving chip based on the third quantized value, the fourth quantized value and a reference working voltage of the driving chip;
the driving chip is provided with a temperature detection mode and a voltage detection mode;
when the controller controls the driving chip to be in a temperature detection mode, the first quantized value is a quantized value of a first voltage value at the reference working temperature, and the second quantized value is a quantized value of the first voltage value at the real-time working temperature;
when the controller controls the driving chip to be in a voltage detection mode, the third quantized value is a quantized value of the first voltage value under the reference working voltage, and the fourth quantized value is a quantized value of the first voltage value under the real-time working voltage.
8. The controller of claim 7, wherein the controller is configured with first calculation logic to calculate a real-time operating temperature of the driver chip based on the first quantized value, the second quantized value, and the reference operating temperature under the first calculation logic;
the first computing logic comprises:
T=T 0 +(D0-DT)*(Q/P)（1）；
wherein T is the real-time operating temperature, T 0 For the reference operating temperature, D0 is the first quantized value, DT is the second quantized value, and P represents a voltage change amount per 1 degree celsius change in temperature; q represents a voltage change amount per 1-code value change of the voltage output module in the driver chip, and P, Q is an integer.
9. The controller of claim 7, wherein the controller is configured with second calculation logic to calculate a real-time operating voltage of the driver chip based on the third quantized value, the fourth quantized value, and the reference operating voltage under the second calculation logic;
the second computational logic includes:
VDD=VDD_DET*DV/D1（2）；
VDD is the real-time operating voltage, VDD _ DET is the first voltage value under the reference operating voltage, DV is the fourth quantized value, and D1 is the third quantized value.
10. An LED driving system, characterized by comprising a controller and at least one driving chip which are connected with each other, wherein the driving chip is the driving chip according to claim 6, and the controller is the controller according to any one of claims 7-9;
the controller sends a first enabling signal to the driving chip so as to enable the driving chip to be switched to a temperature detection mode;
in a temperature detection mode, the driving chip outputs a first quantized value of a first voltage value at a reference working temperature to the controller based on the reference working temperature of the driving chip configured in advance; outputting a second quantized value of the first voltage value at the real-time working temperature to the controller based on the first voltage value of the currently detected driving chip at the real-time working temperature;
the controller calculates and outputs the real-time working temperature based on the first quantized value, the second quantized value and the reference working temperature;
or the like, or a combination thereof,
the controller sends a second enabling signal to the driving chip so as to enable the driving chip to be switched to a voltage detection mode;
in a voltage detection mode, the driving chip outputs a third quantized value of the first voltage value under a reference working voltage to the controller based on the reference working voltage of the driving chip configured in advance; outputting a fourth quantized value of the first voltage value under the real-time working voltage to the controller based on the first voltage value of the currently detected driving chip under the real-time working voltage;
the controller calculates and outputs the real-time operating voltage based on the third quantized value, the fourth quantized value, and the reference operating voltage.
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