TWI497249B - Adjusting circuit and motherboard including the same - Google Patents

Description

Power conditioning circuit and circuit board having the same

The present invention relates to a circuit board, and more particularly to a circuit board having a power conditioning circuit.

In the all-in-one machine, the operating voltage of the LCD monitor is obtained by converting the +19V voltage on the motherboard by an adapter board. Since different liquid crystal monitors have different rated voltages, it is necessary to design different adapter boards for each type of liquid crystal monitor, which makes the cost higher in mass production of an all-in-one machine having different monitors.

In view of the above, it is necessary to provide a power supply adjusting circuit that can be applied to the rated operating voltage of various liquid crystal monitors and a circuit board having the power regulating circuit.

A power conditioning circuit for receiving a voltage of a circuit board to provide a working voltage for a liquid crystal monitor, the power conditioning circuit comprising: a power conditioning module, the input end for receiving the first voltage of the circuit board, the output end and The liquid crystal monitor is connected to a control chip, and the plurality of sensing ends are connected to the liquid crystal monitor for sensing current of the backlight module in the liquid crystal monitor, and the driving end of the control chip is connected to the control end of the power regulating module, and is used for Output corresponding drive according to the current value sensed by the sensing end The power signal control module outputs different operating voltages to the monitor; a connecting device; and a plurality of first resistors, wherein one end of each of the first resistors is connected to a sensing end of the control chip through the connecting device, the first The other end of the resistor is grounded, and the connecting device is configured to control the first resistor to be connected or disconnected from the corresponding sensing end.

A circuit board includes a power conditioning circuit, the power conditioning circuit includes: a power conditioning module, an input end for receiving a first voltage of the circuit board, an output end connected to a liquid crystal monitor; a control chip, the plurality of The sensing end is connected to the liquid crystal monitor for sensing the current of the backlight module in the liquid crystal monitor. The driving end of the control chip is connected to the control end of the power regulating module, and is configured to output according to the current value sensed by the sensing end. The driving signal controls the power regulating module to output different operating voltages to the liquid crystal monitor; a connecting device; and a plurality of first resistors, wherein one end of each of the first resistors is connected to an inductive end of the control chip through the connecting device The other ends of the first resistors are grounded, and the connecting device is configured to control the first resistor to be connected or disconnected from the corresponding sensing end.

The power regulating circuit and the circuit board control the connection or disconnection between the resistor and the sensing end through the connecting device, thereby changing the current sensed by the sensing end of the control chip, so that the power regulating module outputs different voltage values to different liquid crystals. Monitor.

10‧‧‧Power Conditioning Module

Vin‧‧‧ input

Vout‧‧‧ output

C‧‧‧Control end

12‧‧‧Control chip

DRV‧‧‧ drive side

ISEN1, ISEN2, ISEN3, ISEN4‧‧‧ sensing end

S1, S2, S3, S4‧‧ switch

R1, R2, R3, R4, R5, R6, R7, R8‧‧‧ resistance

15‧‧‧Connector

22‧‧‧LCD monitor

1 is a schematic diagram of a first preferred embodiment of a power conditioning circuit of the present invention.

2 is a schematic diagram of a second preferred embodiment of the power conditioning circuit of the present invention.

Referring to FIG. 1, a first preferred embodiment of the power conditioning circuit of the present invention includes a power conditioning module (VRM) 10, a control chip 12, a plurality of switches, and a plurality of first and second resistors.

The input terminal Vin of the power conditioning module 10 is connected to a +19V power supply on a circuit board, and the output terminal Vout is connected to a liquid crystal display (LCD) 22. The power conditioning module 10 is configured to convert the received +19V voltage to a suitable voltage value to provide an operating voltage to the liquid crystal monitor 22.

The control terminal C of the power conditioning module 10 is connected to the driving terminal DRV of the control chip 12, and the sensing terminal of the control chip 12 (the control chip 12 includes four sensing terminals ISEN1-ISEN4 in the embodiment) and the liquid crystal monitor 22 connected. The control chip 12 is configured to control the current state of the backlight module in the liquid crystal monitor 22 according to the sensing terminals ISEN1-ISEN4, and output the corresponding driving signal through the driving terminal DRV to control the working state of the power conditioning module 10, so that the power source The adjustment module 10 outputs a corresponding voltage value to the liquid crystal monitor 22. The input of the control chip 12 is for receiving a pulse width modulation (PWM) signal, which can be used to adjust the brightness of the liquid crystal monitor 22 and the like.

One end of each first resistor is connected to one sensing end of the control chip 12 through a switch, and the other end is grounded; and each second resistor is connected in parallel with a first resistor. In this embodiment, four first resistors R1, R3, R5, and R7 and four second resistors R2, R4, R6, and R8 are included, wherein one end of the first resistor R1 passes through the switch S1 and the sensing end ISEN1 of the control wafer 12. Connected to the other end, the other end is grounded; one end of the first resistor R3 is connected to the sensing terminal ISEN2 of the control chip 12 through the switch S2, and the other end is grounded; one end of the first resistor R5 is connected to the sensing terminal ISEN3 of the control wafer 12 through the switch S3. The other end is grounded; one end of the first resistor R7 is connected to the sensing terminal ISEN4 of the control wafer 12 through the switch S4, and the other end is grounded. The second resistors R2, R4, R6 and R8 are connected in parallel with the first resistors R1, R3, R5 and R7, respectively.

In the present embodiment, the control wafer 12 is a control wafer of the O2 OZ9967 model. According to the specification table of the O2 OZ9967 chip, the control wafer 12 and the power supply adjustment module 10 satisfy the following formula: Wherein V _OUT is the output voltage of the power conditioning module 10, L is the output inductance of the control chip 12, and the I _{LED is} the sum of the currents of the backlight modules in the liquid crystal monitor 22 sensed by the sensing terminals ISEN1-ISEN4 of the control chip 12. D is the duty cycle of the PWM signal received by the control chip 12, and T is the operating period of the control wafer 12.

It can be seen from the above formula that the output voltage V _{OUT of} the power conditioning module 10 is proportional to the current I _LED received by the control wafer 12, that is, as long as the current I _LED received by the control wafer 12 is changed. The output voltage V _{OUT of} the power conditioning module 10 can be changed.

Thus, the designer can adjust the closing or opening of the switches S1-S4 according to the specifications of the different liquid crystal monitors, so that the current I _LED received by the control wafer 12 can be changed correspondingly. For example, when it is known that the rated voltage of the first liquid crystal monitor to be used is V1 and the current output by the backlight module is I1, according to the output voltage V _{OUT of} the power conditioning module 10 and the current I received by the control wafer 12 proportional relationship between the _LED shows that, when the switches S1-S4 are all turned off currents induced within the control wafer end ISEN1-ISEN4 sensed by the first liquid crystal monitor and I _LED backlight module such that the power supply to The output voltage V _OUT of the adjustment module 10 is equal to the rated voltage value of the first liquid crystal monitor. When it is known that the rated voltage of the second liquid crystal monitor to be used is V2 (where V2 is less than V1) and the current output by the backlight module thereof is I2 (where I2 is smaller than I1), the output voltage of the power supply regulating module 10 is V _OUT The proportional relationship between the current I _LED received by the control chip 12 and the second liquid crystal monitor 22 sensed by the sensing terminals ISEN1-ISEN4 of the control chip when the switch S1 is closed and the switches S2-S4 are turned off. within the current I _LED backlight module and to the power conditioning module such that the output voltage V _OUT 10 is equal to the rated voltage value of the second liquid crystal monitor.

In the above description, the switch S1 is closed to cause the resistors R1 and R2 to shunt the current induced by the sensing terminal ISEN1 of the control wafer 12, thereby causing the second liquid crystal sensed by the sensing terminals ISEN1-ISEN4 of the control wafer 12. within the monitor current and I _LED backlight module becomes relatively small, so that the case is further such that the output of the voltage regulator module 10 using a first relative voltage V _OUT when the LCD monitor the voltage regulating module 10 output voltage V _OUT Smaller.

Referring to FIG. 2, a second preferred embodiment of the power conditioning circuit of the present invention is used. In the second embodiment, a connector 15 replaces the four switches S1-S4 in the first embodiment. The connector 15 includes four sets of pins, each set of pins includes a first pin and a second pin, wherein a first one of the four sets of pins corresponds to the control chip 12 The sensing terminals ISEN1-ISEN4 are connected, and the second pins are grounded through the first resistors (R1, R3, R5 and R7), respectively. The sensing terminals ISEN1-ISEN4 of the control wafer 12 are also connected to the liquid crystal monitor 22. The first pin and the second pin of each set of pins are connected through a jump cap. The second resistors R2, R4, R6 and R8 are connected in parallel with the first resistors R1, R3, R5 and R7, respectively.

Similar to the first embodiment, the designer can connect or disconnect the corresponding first pin and the second pin through the jump cap according to the specifications of different liquid crystal monitors, so that the current received by the control wafer 12 can be changed correspondingly. I _LED . For example, when the first liquid crystal monitor needs to be used, the first pin and the second pin of the four sets of pins are disconnected, so that the output voltage V _{OUT of} the power regulating module 10 is equal to the first liquid crystal monitor. Rated voltage value. When the second liquid crystal monitor is needed, the first pin of the first group of pins is connected to the second pin, and the first pin and the second pin of the other group of pins are disconnected, so that the power source is The output voltage V _OUT of the adjustment module 10 is equal to the rated voltage value of the second liquid crystal monitor. Of course, in other embodiments, the switch and the connector may be other connecting devices as long as they can control the connection or disconnection between the resistor and the corresponding sensing end.

In summary, the present invention complies with the requirements of the invention patent and submits a patent application according to law. The above description is only the preferred embodiment of the present invention, and equivalent modifications or variations made by those skilled in the art will be included in the following claims.

10‧‧‧Power Conditioning Module

Vin‧‧‧ input

Vout‧‧‧ output

C‧‧‧Control end

12‧‧‧Control chip

DRV‧‧‧ drive side

ISEN1, ISEN2, ISEN3, ISEN4‧‧‧ sensing end

S1, S2, S3, S4‧‧ switch

R1, R2, R3, R4, R5, R6, R7, R8‧‧‧ resistance

22‧‧‧LCD monitor

Claims (8)

A power conditioning circuit for receiving a voltage of a circuit board to provide a working voltage for a liquid crystal monitor, the power conditioning circuit comprising: a power conditioning module, the input end for receiving the first voltage of the circuit board, the output end and The liquid crystal monitor is connected to a control chip, and the plurality of sensing ends are connected to the liquid crystal monitor for sensing current of the backlight module in the liquid crystal monitor, and the driving end of the control chip is connected to the control end of the power regulating module, Outputting a corresponding driving signal according to the current value sensed by the sensing end to control the power regulating module to output different working voltages to the liquid crystal monitor; a connecting device; and a plurality of first resistors, wherein one end of each of the first resistors transmits The connecting device is connected to a sensing end of the control chip, and the other ends of the first resistors are grounded. The connecting device is configured to control the first resistor to be connected or disconnected from the corresponding sensing end. The power conditioning circuit of claim 1, further comprising a plurality of second resistors, wherein each of the second resistors is connected in parallel with a first resistor. The power conditioning circuit of claim 1 or 2, wherein the connecting device comprises a plurality of switches. The power conditioning circuit of claim 1 or 2, wherein the connecting device comprises a connector, the connector comprising a plurality of pairs of pins, wherein the first pin of each pair of pins and the control A sensing end of the chip is connected, and the second pin is connected to a first resistor, and each pair of pins of the connector is connected or disconnected through a jump cap. A circuit board includes a power conditioning circuit, the power conditioning circuit includes: a power conditioning module, the input end of which is configured to receive a first voltage of the circuit board, and the output end a liquid crystal monitor is connected; a control chip, the plurality of sensing ends are connected to the liquid crystal monitor for sensing current of the backlight module in the liquid crystal monitor, and the driving end of the control chip is connected to the control end of the power regulating module, Outputting a corresponding driving signal according to the current value sensed by the sensing end to control the power regulating module to output different working voltages to the liquid crystal monitor; a connecting device; and a plurality of first resistors, wherein one end of each of the first resistors transmits The connecting device is connected to a sensing end of the control chip, and the other ends of the first resistors are grounded. The connecting device is configured to control the first resistor to be connected or disconnected from the corresponding sensing end. The circuit board of claim 5, further comprising a plurality of second resistors, wherein each of the second resistors is connected in parallel with a first resistor. The circuit board of claim 5, wherein the connecting device comprises a plurality of switches. The circuit board of claim 5, wherein the connecting device comprises a connector, the connector comprising a plurality of pairs of pins, wherein the first pin of each pair of pins and the control chip One of the sensing ends is connected, and the second pin is connected to a first resistor, and each pair of pins of the connector is connected or disconnected through a jump cap.