CN202455264U - DC/DC converter and control circuit, light-emitting device and electronic equipment thereof - Google Patents
DC/DC converter and control circuit, light-emitting device and electronic equipment thereof Download PDFInfo
- Publication number
- CN202455264U CN202455264U CN2011203343274U CN201120334327U CN202455264U CN 202455264 U CN202455264 U CN 202455264U CN 2011203343274 U CN2011203343274 U CN 2011203343274U CN 201120334327 U CN201120334327 U CN 201120334327U CN 202455264 U CN202455264 U CN 202455264U
- Authority
- CN
- China
- Prior art keywords
- signal
- voltage
- capacitor
- converter
- control circuit
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
Images
Abstract
The present utility model provides a DC/DC converter and a control circuit, a light-emitting device and electronic equipment thereof. Thus the area of the control circuit of the DC/DC converter can be reduced. A charging circuit (30) is used for charging a capacitor (C2). A discharging circuit (32) is used for discharging the capacitor when the circuit is in the open state. A comparator (38) is used for generating unblocking signals (S1), the level of which is changed according to voltage (VC2) of the capacitor. A logic unit (40) is used for presenting fault signals (S3) if anomaly detection signals (S2) are valid, when the unblocking signals are converted into fixed time of a first level, if the anomaly detection signals are invalid, the fault signals (S3) can be canceled, and in the fixed time, if the anomaly detection signals are valid, the fault signals are kept being presented. Moreover, the logic unit (40) is used for controlling the discharging circuit according to the unblocking signals. A reversal amplifier (46) is sued for generating soft starting voltage (VSS) through reversing voltage of the capacitor.
Description
Technical field
The utility model relates to the control circuit of DC-DC (DC/DC) converter.
Background technology
In order direct voltages such as cell voltage to be boosted or step-down, utilize the DC/DC converter.The control circuit of DC/DC converter detect in the DC/DC converter, produce unusually, for example overvoltage condition, overcurrent condition, temperature anomaly state etc., and in abnormality, carry out circuit protection.Control circuit has the timer circuit of keeping watch on abnormality, judges during the judgement of each regulation whether abnormality is continuing.In addition, control circuit comprises in order when it starts, to prevent impulse current, generates the soft starting circuit of the soft start voltage that slowly rises in time.Control circuit makes the output voltage of DC/DC converter follow soft start voltage and increase.
[patent documentation 1] (Japan) spy opens flat 9-121535 communique
[patent documentation 2] (Japan) spy opens flat 7-336999 communique
Because timer circuit that abnormality detection is used and soft starting circuit need plug-in capacitor respectively, so number of parts increases.In addition, need be used to connect two lead-in wires (pad) of plug-in capacitor in the control circuit, so chip size, package dimension become big.
Implement novel content
The utility model is in view of such problem and accomplishing, and one of purpose of the exemplary of an one of which mode is to reduce the size of the control circuit of DC/DC converter.
The a certain mode of this execution mode relates to the control circuit of DC to DC converter.Control circuit comprises: capacitor, and the current potential of its 1st terminal is fixed; Charging circuit charges to capacitor; Discharge circuit can switch and open, turn-offs, and when opening state, capacitor is discharged; Comparator; The voltage that is created on capacitor is got the 1st level from the upside threshold voltage that reaches regulation during the downside threshold voltage that is reduced to regulation, the voltage of capacitor from be reduced to the downside threshold voltage up to reach the upside threshold voltage during get the 2nd level ring off signal; Logical block is accepted ring off signal and if detect abnormality then by effective anomaly detection signal, is effectively then presented fault-signal as if anomaly detection signal; Then, change the timing of said the 1st level into, if anomaly detection signal is disabled in ring off signal; Then cancel fault-signal, at this regularly, if anomaly detection signal is by effective; Then continue to appear fault-signal, and when ring off signal is the 1st level, open discharge circuit, when ring off signal is the 2nd level, turn-off discharge circuit; And reversal amplifier, generate soft start voltage thereby reverse through voltage to capacitor.
According to this mode, can the slope that generate in the timer circuit of using in abnormality detection (slope) voltage be utilized as soft start voltage after discharging from abnormality.Its result can shared timer circuit and soft starting circuit, can reduce size.
The control circuit of this execution mode can also comprise: switch is arranged on the path of said soft start voltage of lead-out terminal side of said reversal amplifier.
Switch also can turn-off during effectively at said fault-signal, said fault-signal be disabled during open-minded.
Logical block also can be included in the said anomaly detection signal of input on its set terminal, the preferential set-reset flip-floop of set of input ring off signal on its reseting terminal.
Logical block can also comprise: the OR door generates the counter-rotating output signal and the logic OR of removing signal of set-reset flip-floop, and controls discharge circuit.
Logical block can also comprise: the 2OR door; When having been surpassed the threshold value of regulation by effective the 1st over-current detection signal, the electric current that in the switching transistor of said DC to DC converter, flows through when being received in the electric current that flows through in the load of said DC to DC converter and having surpassed the threshold value of regulation by effective the 2nd over-current detection signal and when the output voltage of said DC to DC converter has surpassed the threshold value of regulation by effective excess voltage detection signal, and generate said anomaly detection signal.
The other type of the utility model is a DC to DC converter.This DC to DC converter comprises above-mentioned control circuit.
The another mode of the utility model is a light-emitting device.This light-emitting device comprises light-emitting component and light-emitting component is provided the above-mentioned DC to DC converter of driving voltage.
The another mode of the utility model is an electronic equipment.The above-mentioned light-emitting device that this electronic equipment comprises liquid crystal panel and is provided with as the backlight of liquid crystal panel.
In addition, the combination in any of above formation element or also be effective as the mode of the utility model with the formation element of the utility model or the mode that shows mutual alternative between method, device, the system etc.
According to the mode of the utility model, can cut down circuit area.
Description of drawings
Fig. 1 is the circuit diagram of structure of the electronic equipment of the expression drive circuit that comprises execution mode.
Fig. 2 is the sequential chart of action of the drive circuit of presentation graphs 1.
Label declaration
2... electronic equipment; 3... light-emitting device; 4... drive circuit; 5...LCD panel; 6...LED string; C2... capacitor; 30... charging circuit; 32... discharge circuit; 34... resistance; 36... transistor; 38... comparator; 40... logical block; 42...SR trigger; 44...OR door; 46... reversal amplifier; 50... output circuit; 52... inverter; 54... transistor; SW1... switch; 100... control IC; 102... output circuit; EA1... error amplifier; DR1... the 1st driver; CMP1... the 1st comparator; CMP2... the 2nd comparator; CMP3... the 3rd comparator; R1... the 1st detect resistance; R2... the 2nd detect resistance; L1... inductor; C1... output capacitor; D1... rectifier diode; M1... switching transistor; OCP1... the 1st over-current detection signal; OCP2... the 2nd over-current detection signal; OVP... excess voltage detection signal; S1... ring off signal; S2... anomaly detection signal; S3... fault-signal
Embodiment
Below, based on preferred implementation and with reference to accompanying drawing the utility model is described.Suppose to the shown identical or formation element that is equal to of each accompanying drawing, member, processing additional phase with label, and suitably omit the explanation of repetition.In addition, execution mode is that illustration is not to be used to limit utility model, and all characteristics that execution mode is recorded and narrated or its combination may not be defined as the content of the internal of utility model.
In this manual, " state that member A is connected with member B " comprises that also member A and member B are via not bringing other members of influence and situation about being connected indirectly to status of electrically connecting except member A and the physically direct-connected situation of member B.
Likewise, " member C is arranged on the state between member A and the member B " also comprises via not bringing other members of influence and situation about indirectly connecting to status of electrically connecting except member A and member C or member B and the direct-connected situation of member C.
Fig. 1 is the circuit diagram of structure of the electronic equipment 2 of the expression DC/DC converter that comprises execution mode.
Light-emitting device 3 comprises the LED string 6 and its drive circuit 4 as light-emitting component.
Drive circuit (DC/DC converter) 4 comprises control IC 100 and output circuit 102.Output circuit 102 comprises inductor L1, rectifier diode D1, switching transistor M1, output capacitor C1.The topology of output circuit 102 (topology) is general, therefore omits explanation.
The switch terminal P4 of control IC 100 is connected with the grid of switching transistor M1.Control IC 100 obtains the required output voltage V out that lights of LED string 6, and through the duty ratio of opening, turn-offing that feedback is come by-pass cock transistor M1, makes to flow through and object brightness corresponding driving electric current in the LED string 6.In addition, switching transistor M1 also can be built in the control IC 100.
The 1st detection resistance R 1 is arranged on the path of LED string 6, specifically is arranged between the negative electrode and earth terminal of LED string 6.Error amplifier EA1 amplifies the 1st and detects the pressure drop V that produces on the resistance R 1
R1With control voltage V
DIMError, and generated error voltage V
FBOscillator 60 generates the periodic voltage V of triangular wave or sawtooth waveforms
OSCPWM comparator PWM_CMP accepts periodic voltage V
OSC, after the soft start voltage V that states
SSAnd error voltage V
FBThe softer starting resistor V of PWM comparator PWM_CMP
SSWith error voltage V
FBIn a lower side and periodic voltage V
OSCThe duty ratio of the output of PWM comparator PWM_CMP (door pulse signal G1) is conditioned and makes the 1st to detect the pressure drop V of resistance R 1
R1With control voltage V
DIMConsistent.Driver DR1 drives the switching transistor M1 of DC/DC converter based on door pulse signal G1.In addition, also can replace pulse width modulator and use pulse frequency modulator.
The 1st comparator C MP1 is at the pressure drop V of the 1st detection resistance R 1
R1Surpass the 1st threshold voltage V
TH1The time, present (assert) the 1st over-current detection signal OCP1.The 2nd detects on the path of switching transistor M1 that resistance R 2 is arranged on the DC/DC converter.The 2nd comparator C MP2 is at the pressure drop V of the 2nd detection resistance R 2
R2Surpass the 2nd threshold voltage V
TH2The time, present the 2nd over-current detection signal OCP2.
Resistance R 3, R4 carry out dividing potential drop to driving voltage Vout.Overvoltage detects the 3rd comparator C MP3 of usefulness relatively through resistance R 3, R4 voltage after partial Vout ' and fixing threshold voltage V
TH3The 3rd comparator C MP3 is at Vout '＞V
TH3The time, present excess voltage detection signal OVP.
At least one in detection signal OCP1, OCP2, OVP of driver DR1 is fixed as low level with door pulse signal G1 during by effectively (assert) immediately, and stopcock transistor M1, thereby stops the switch motion of DC/DC.
Capacitor C2 is hung on capacitor terminal P5 outward.The end of capacitor C2 (the 1st terminal) ground connection and current potential is fixed.30 pairs of capacitor C2 chargings of charging circuit.Discharge circuit 32 can switch to be opened, turn-offs, and in opening state, capacitor C2 is discharged.Discharge circuit 32 is included in resistance 34 and the transistor 36 that is connected in series on the discharge path.When transistor 36 was opened, discharge circuit 32 became opening state, and when transistor 36 turn-offed, discharge circuit 32 became off state.
Ring off signal S1 is used to the switching of opening, turn-offing of discharge circuit 32, and the forward edge of ring off signal S1 (positive edge) utilizes as the timing of judging abnormality once more.Logical block 40 is accepted ring off signal S1 and anomaly detection signal S2.Anomaly detection signal S2 is in light-emitting device 3 then can be by effective signal if detect some abnormalities, for example through OR door 39 get above-mentioned detection signal OCP1, OCP2, OVP etc. " or " generate.Also can be except these detection signals; Perhaps replace these detection signals, UVLO (the Under Voltage Lock Out) signal of the low-voltage state of the supply voltage that the 39 acceptance expressions of OR door provide from the outside, THD (the Thermal Shut Down) signal of expression temperature anomaly etc.
In addition, logical block 40 is opened discharge circuit 32 when ring off signal S1 is the 1st level (high level), when ring off signal S1 is the 2nd level (low level), turn-offs discharge circuit 32.
The counter-rotating output signal #Q (counter-rotating of # presentation logic) of set-reset flip-floop 42 is equivalent to fault-signal S3.OR door 44 generation fault-signal S3 and releasing signal S1 " or ", and control discharge circuit 32.
It more than is the structure of drive circuit 4.Its action then is described.Fig. 2 is the sequential chart of action of the drive circuit 4 of presentation graphs 1.At moment t0, if anomaly detection signal S2 quilt effectively, then the counter-rotating of set-reset flip-floop 42 output #Q changes low level into, and fault-signal S3 quilt is (low level) effectively.
If fault-signal S3 becomes low level, then transistor 36 turn-offs, and discharge circuit 32 becomes off state, through 30 pairs of capacitor C2 chargings of charging circuit, condenser voltage V
C2Rise.At moment t1 if condenser voltage V
C2Reach upside threshold voltage VH, then ring off signal S1 changes high level into.
Even S1 changes high level in moment t1 ring off signal, anomaly detection signal S2 is also by effectively, and therefore according to priority logic is set, set-reset flip-floop 42 is not reset, and fault-signal S3 continues to keep low level.If ring off signal S1 changes high level into, then transistor 36 is open-minded, and capacitor C2 is discharged, condenser voltage V
C2Begin to reduce.If condenser voltage V
C2Be reduced to downside threshold voltage VL, then ring off signal S1 changes low level (t2) into, and capacitor C2 is recharged once more.At moment t3 if condenser voltage V
C2Reach upside threshold voltage VH, then ring off signal S1 becomes high level.
If switch SW 1 is open-minded, then the output voltage V of reversal amplifier 46
SSBe provided for PWM comparator PWM_CMP.Its result, the duty ratio of door pulse signal G1 increases in time, and output voltage V out slowly rises.
It more than is the action of drive circuit 4.
According to control IC 100, through single capacitor C2 is discharged and recharged, thereby can generate ring off signal S1 and soft start voltage V as periodic signal
SSThus, need two capacitor can be reduced to one in the past, and therefore can cut down circuit area.
In addition, owing to be that capacitor C2 is gone up the voltage V that produces
C2The counter-rotating of descending slope and generate soft start voltage V
SS, therefore, then can begin to generate soft start voltage V immediately if fault-signal S3 is disabled
SS
More than, based on execution mode the utility model has been described.This execution mode is an illustration, constitutes these each in element or each treatment progress, their combination, can have various variation.Below, such variation is described.
In execution mode, explained through making the 1st on the path that is arranged on LED string 6 detect the pressure drop V of resistance R 1
R1With desired value V
DIMUnanimity, thereby the structure of stabilized driving electric current, but the utility model is not limited thereto.For example also can on LED goes here and there 6 path, the constant-current source (current driver) that generates stable drive current be set.
The Switching Power Supply of the nonisulated type that uses inductor has been described, but the utility model also can be applied to use the Switching Power Supply of the insulated type of transformer in execution mode.
In execution mode, as the application of light-emitting device 3 electronic equipment has been described, but purposes is not limited thereto, also can be applied to illumination etc.
In addition, in this execution mode, the setting of high level, low level logical signal is an example, can be through suitably counter-rotating and change freely such as inverter.
Based on execution mode; Use concrete words and phrases that the utility model has been described; But execution mode only illustrates principle, the application of the utility model, in the scope of the thought of the utility model that does not break away from claims defined, permits the change of a lot of variation and configuration in the execution mode.
Claims (9)
1. the control circuit of a DC to DC converter is characterized in that, comprising:
Capacitor, the current potential of its 1st terminal is fixed;
Charging circuit is to said capacitor charging;
Discharge circuit can switch and open, turn-offs, and when opening state, said capacitor is discharged;
Comparator; The voltage that is created on said capacitor is got the 1st level from the upside threshold voltage that reaches regulation during the downside threshold voltage that is reduced to regulation, the voltage of said capacitor from be reduced to said downside threshold voltage up to reach said upside threshold voltage during get the 2nd level ring off signal;
Logical block is accepted said ring off signal and if detect abnormality then by effective anomaly detection signal, is effectively then presented fault-signal as if said anomaly detection signal; Then, change the timing of said the 1st level into, if said anomaly detection signal is disabled in said ring off signal; Then cancel said fault-signal; At this regularly, if said anomaly detection signal is then continued to appear said fault-signal by effective; And when said ring off signal is said the 1st level, open said discharge circuit, when said ring off signal is said the 2nd level, turn-off said discharge circuit; And
Reversal amplifier generates soft start voltage thereby reverse through the voltage to said capacitor.
2. control circuit as claimed in claim 1 is characterized in that, also comprises:
Switch is arranged on the path of said soft start voltage of lead-out terminal side of said reversal amplifier.
3. control circuit as claimed in claim 2 is characterized in that,
Said switch turn-offs during effectively at said fault-signal, said fault-signal be disabled during open-minded.
4. like each described control circuit of claim 1 to 3, it is characterized in that,
Said logical block is included in the said anomaly detection signal of input on its set terminal, the preferential set-reset flip-floop of set of the said ring off signal of input on its reseting terminal.
5. control circuit as claimed in claim 4 is characterized in that,
Said logical block also comprises:
The OR door generates the counter-rotating output signal of said set-reset flip-floop and the logic OR of said ring off signal, and controls said discharge circuit.
6. control circuit as claimed in claim 1 is characterized in that,
Said logical block also comprises:
The 2OR door; When having been surpassed the threshold value of regulation by effective the 1st over-current detection signal, the electric current that in the switching transistor of said DC to DC converter, flows through when being received in the electric current that flows through in the load of said DC to DC converter and having surpassed the threshold value of regulation by effective the 2nd over-current detection signal and when the output voltage of said DC to DC converter has surpassed the threshold value of regulation by effective excess voltage detection signal, and generate said anomaly detection signal.
7. a DC to DC converter is characterized in that, comprises each described control circuit of claim 1 to 3.
8. a light-emitting device is characterized in that, comprising:
Light-emitting component; And
Said light-emitting component is provided the described DC to DC converter of claim 7 of driving voltage.
9. an electronic equipment is characterized in that, comprising:
Liquid crystal panel; And
The described light-emitting device of claim 8 that is provided with as the backlight of said liquid crystal panel.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2010-200203 | 2010-09-07 | ||
| JP2010200203A JP2012060743A (en) | 2010-09-07 | 2010-09-07 | Control circuit of dc/dc converter, dc/dc converter using the same, light emitting device and electronic device |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN202455264U true CN202455264U (en) | 2012-09-26 |
Family
ID=46057190
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN2011203343274U Expired - Lifetime CN202455264U (en) | 2010-09-07 | 2011-09-07 | DC/DC converter and control circuit, light-emitting device and electronic equipment thereof |
Country Status (2)
| Country | Link |
|---|---|
| JP (1) | JP2012060743A (en) |
| CN (1) | CN202455264U (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106549569A (en) * | 2015-09-22 | 2017-03-29 | 意法半导体股份有限公司 | For managing the method and corresponding DC-DC step-down controllers of multiple sluggish DC-DC step-down controllers |
| CN107634567A (en) * | 2016-07-15 | 2018-01-26 | 戴洛格半导体公司 | Short-circuit protection for data-interface charging |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP6182972B2 (en) * | 2013-05-15 | 2017-08-23 | 三菱電機株式会社 | Lighting device and lighting device |
| JP6247455B2 (en) * | 2013-05-17 | 2017-12-13 | ローム株式会社 | LIGHT EMITTING ELEMENT DRIVE CIRCUIT, AND LIGHT EMITTING DEVICE AND ELECTRONIC DEVICE USING THE SAME |
| CN111406441B (en) * | 2017-11-10 | 2022-10-28 | 亮锐控股有限公司 | Driver for LED array |
| JP2019115189A (en) | 2017-12-25 | 2019-07-11 | 旭化成エレクトロニクス株式会社 | Power supply apparatus |
-
2010
- 2010-09-07 JP JP2010200203A patent/JP2012060743A/en active Pending
-
2011
- 2011-09-07 CN CN2011203343274U patent/CN202455264U/en not_active Expired - Lifetime
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106549569A (en) * | 2015-09-22 | 2017-03-29 | 意法半导体股份有限公司 | For managing the method and corresponding DC-DC step-down controllers of multiple sluggish DC-DC step-down controllers |
| CN106549569B (en) * | 2015-09-22 | 2019-09-24 | 意法半导体股份有限公司 | For manage multiple sluggishness DC-DC buck converters method and corresponding DC-DC buck converter |
| CN107634567A (en) * | 2016-07-15 | 2018-01-26 | 戴洛格半导体公司 | Short-circuit protection for data-interface charging |
| CN107634567B (en) * | 2016-07-15 | 2020-07-07 | 戴洛格半导体公司 | Short circuit protection for charging of data interface |
Also Published As
| Publication number | Publication date |
|---|---|
| JP2012060743A (en) | 2012-03-22 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN202310187U (en) | Driving circuit of luminous element, luminous device using same, and electronic equipment | |
| CN104467369B (en) | System and Method for a Switch Driver | |
| CN103702486B (en) | LED driving circuit system, control circuit and control method | |
| CN202455264U (en) | DC/DC converter and control circuit, light-emitting device and electronic equipment thereof | |
| US9559586B2 (en) | Switch mode power supply, control circuit and associated control method | |
| TWI568155B (en) | System and method for high efficiency pfm control for buck-boost converter and regulator | |
| TWI491152B (en) | Method for adjusting the operation of a semiconductor component and method for adjusting a threshold voltage | |
| US7944721B2 (en) | Switching control circuit for multi-channels and multi-phases power converter operated at continuous current mode | |
| TWI483518B (en) | A control circuit for a switching regulator receiving an input voltage and a method for controlling a main switch and a low-side switch using a constant on-time control scheme in a switching regulator | |
| US9698677B2 (en) | Brownout recovery circuit for bootstrap capacitor and switch power supply circuit | |
| US7830131B2 (en) | Control circuit for switching regulator | |
| US7888918B2 (en) | Control circuit for multi-phase converter | |
| US20120265354A1 (en) | Circuit and method for maximum power point tracking of solar panel | |
| CN101212178A (en) | Current-mode controlled switching regulator and control method therefor | |
| JP2006340538A (en) | Switching power supply | |
| US8797011B2 (en) | Variable current limiter for regulator | |
| US20080225560A1 (en) | Switching controller for parallel power converters | |
| EP3597010B1 (en) | Emergency lighting converter | |
| JP2010154706A (en) | Control circuit and method of switching regulator, and switching regulator using the same | |
| CN101800468A (en) | Parallel power factor correction converter | |
| TWI410173B (en) | Led driver and driving method | |
| US8497719B2 (en) | Slew rate PWM controlled charge pump for limited in-rush current switch driving | |
| CN112653324B (en) | Boost converter system without direct power supply | |
| JP2007189771A (en) | Power unit | |
| CN210839348U (en) | Non-isolated buck-boost converter |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CX01 | Expiry of patent term |
Granted publication date: 20120926 |
|
| CX01 | Expiry of patent term |