CN102339080A

CN102339080A - Device and method for revising output voltage of primary side feedback flyback type power module

Info

Publication number: CN102339080A
Application number: CN2010102300661A
Authority: CN
Inventors: 唐健夫; 陈曜洲; 戴良彬
Original assignee: Richtek Technology Corp
Current assignee: Richtek Technology Corp
Priority date: 2010-07-19
Filing date: 2010-07-19
Publication date: 2012-02-01
Anticipated expiration: 2030-07-19
Also published as: CN102339080B

Abstract

The invention discloses a device and a method for revising an output voltage of a primary side feedback flyback type power module. The difference value between the value of the output voltage of the power module and a target value is captured, and a reference voltage used for regulating the output voltage is regulated according to the difference value, so the value of the output voltage is revised to the target value.

Description

Proofread and correct primary side and feedback the device and method of output voltage of flyback power module

Technical field

The present invention relates to close a kind of primary side and feedback flyback power module, particularly a kind of primary side of proofreading and correct is feedback the device and method of output voltage of flyback power module.

Background technology

Flyback power module use transformer from the primary side transmitted power to secondary side.Regulate output voltage in order to obtain feedback signal from secondary side, secondary side needs voltage sensor, for example the combination of voltage stabilizer (shuntregulator) and photo-coupler.Yet these circuit can increase the size and the cost of power module.

In order to reduce size and cost, also there is flyback power module to obtain output information and comes regulated output voltage from primary side, for example U.S. Patent number 5,438, and 499,6,480,399,6; 721,192,6,781,357,6,833,692,6; 862,194,6,967,472 and 6,977,824.Yet this primary side is feedback flyback power module in default of secondary side information, so when error appearred in turn ratio, supply voltage or the diode of resistance, transformer, skew can appear in output voltage.If will obtain accurate output information, then need transformer and secondary side assembly accurately, but this is a very big problem to cost and a large amount of QC of producing.

Summary of the invention

The object of the invention is to propose a kind of primary side of proofreading and correct and feedbacks the device and method of output voltage of flyback power module.

According to the present invention; A kind of primary side of proofreading and correct is feedback the device of output voltage of flyback power module and is comprised that internal memory, digital analog converter, programmable unit and adjustment circuit arrangement are used for regulating the reference voltage of this output voltage for adjustment, thereby to proofread and correct this output voltage be desired value.

According to the present invention; A kind of primary side of proofreading and correct is feedback the method for output voltage of flyback power module and is comprised that primary side earth terminal and secondary side earth terminal with this power module link together; The power input of input voltage to this power module is provided; The output voltage of detecting this power module produces detection signal; Capture this detection signal and be used for regulating the difference between the reference voltage of this output voltage, produce adjustment voltage according to this difference, and according to this this reference voltage of adjustment voltage adjustment.

When power module is tested, can capture the difference adjustment reference voltage between output voltage and the desired value by the above-mentioned device and method of mat, and then overcome because the output voltage that non-ideal factor the caused skew of transformer and other assembly.

Description of drawings

Fig. 1 is embodiments of the invention; And

Fig. 2 is for to connect the synoptic diagram that power module carries out module testing with test circuit.

Embodiment

Fig. 1 is embodiments of the invention; In primary side is feedback flyback power module 10; Transformer T1 has first siding ring Lp and power switch M1 is connected between power input VIN and the primary side earth terminal GND; Second siding ring Ls is connected between power output end Vout and the secondary side earth terminal VSS, and the voltage of primary side ancillary coil La induction second siding ring Ls, thereby records output voltage V o indirectly; And produce induced voltage Va and produced feedback voltage VFB by resistance R 1 and R2 dividing potential drop and provide control signal Sc power switched switch M1 to become output voltage V o for control integrated circuit 12, control integrated circuit 12 with conversion input voltage Vi.In control integrated circuit 12, the difference that error amplifier 34 amplifies between reference voltage Vr2 and the feedback voltage VFB produces the dutycycle that error signal Ve supplies controller 32 modulation power switch M1, thereby regulates output voltage V o in stable desired value.Energy gap reference voltage generator (bandgap voltagereference generator) 22 provides reference voltage Vr1, and programmable unit 14, internal memory 24, digital analog converter 26 and adjustment circuit 28 are configured to adjust reference voltage Vr1 becomes reference voltage Vr2.More specifically, programmable unit 14 is according to the signal generation data D of the input end PI able to programme of reference voltage Vr1 and power module 10 and with in its write memory 24.Internal memory 24 can be single programmable (One TimeProgrammable; OTP) internal memory or multiple programmable (Multiple Time Programmable; MTP) internal memory.Digital analog converter 26 reads the data D of internal memory 24 storages and is converted into adjustment voltage Vm.In this embodiment, adjustment circuit 28 comprises that totalizer 30 will adjust voltage Vm and reference voltage Vr1 addition and produce reference voltage Vr2.Because reference voltage Vr2 system is used for regulating output voltage V o, therefore changing adjustment voltage Vm is recoverable output voltage V o.In programmable unit 14, the difference DELTA V between the signal of difference extractor 20 acquisition reference voltage Vr1 and input end PI able to programme, scrambler 18 converts difference DELTA V into data D, and cd-rom recorder 16 is with data D write memory 24.

Fig. 2 is for connecting the synoptic diagram that power module 10 carries out module testing with test circuit 36; Test circuit 36 links together the primary side earth terminal GND and the secondary side earth terminal VSS of power module 10; Provide AC-input voltage Vi to power input VIN, and the output voltage V o generation detection signal Vd that utilizes resistance R 3 and R4 to form voltage divider detecting power output end Vout send into input end PI able to programme.With reference to Fig. 1 and Fig. 2, because goal-selling value and the reference voltage Vr1 of output voltage V o are known, therefore can suitably select resistance R 3 and R4, make detection signal Vd when output voltage V o equals the goal-selling value, can equal reference voltage Vr1.Under ideal state, Vm=0, Vr2=Vr1.If output voltage V o is not equal to preset target value; Then detection signal Vd also is not equal to reference voltage Vr1; Therefore the difference DELTA V of programmable unit 14 generations will not be 0; Data converted D is written into internal memory 24 thus, and the adjustment voltage Vm that digital analog converter 26 will produce non-zero supplies adjustment circuit 28 adjustment Vr1 to become Vr2=Vr1+Vm, becomes preset target value to proofread and correct output voltage V o.

Known in the art, output voltage V o has ripple (ripple).The desired value of output voltage V o reaches the correction to output voltage V o among this paper, all is meant the accurate position of direct current (direct current (DC) level).

Claims

1. proofread and correct primary side and feedback the device of output voltage of flyback power module for one kind, it is characterized in that, the output voltage of this power module is according to reference voltage and conditioned, and this device comprises:

Internal memory;

Digital analog converter connects this internal memory, according to the data decision adjustment voltage of this memory storage;

Programmable unit connects the input end able to programme of this internal memory, this power module, produces these data according to the signal of this reference voltage and this input end able to programme, and these data are write this internal memory; And

The adjustment circuit connects this digital analog converter, according to this this reference voltage of adjustment voltage adjustment.

2. device as claimed in claim 1 is characterized in that, this programmable unit comprises:

The difference extractor connects this input end able to programme, in order to the signal that captures this input end able to programme and the difference between this reference voltage;

Scrambler connects this difference extractor, converts this difference into this data; And

Cd-rom recorder connects this scrambler and internal memory, in order to these data are write this internal memory.

3. device as claimed in claim 1 is characterized in that, saves as the single programmable internal memory in this.

4. device as claimed in claim 1 is characterized in that, saves as the multiple programmable internal memory in this.

5. device as claimed in claim 1 is characterized in that, this adjustment circuit comprises totalizer, should adjust voltage and add this reference voltage.

6. proofread and correct primary side and feedback the method for output voltage of flyback power module for one kind; It is characterized in that; This power module comprises transformer and has first siding ring between the power input and primary side earth terminal of this power module; And second siding ring is between the power output end and secondary side earth terminal of this power module, and this power output end provides the output voltage of regulating according to reference voltage, and this method comprises the following steps:

(A) this primary side earth terminal and secondary side earth terminal are linked together;

(B) provide input voltage to this power input;

(C) detect this output voltage and produce detection signal;

(D) capture difference between this detection signal and this reference voltage;

(E) produce adjustment voltage according to this difference; And

(F) according to this this reference voltage of adjustment voltage adjustment.

7. method as claimed in claim 6 is characterized in that, this step e comprises: this difference of encoding produces data;

With this data write memory; And

Read and change these data from this internal memory and produce this adjustment voltage.