HT7A6322 Flyback Configuration Low Cost Power Supply · HT7A6322 Flyback Configuration Low Cost Power Supply . AN0373E V1.20 1 / 16 March 1, 2018 . ... Pin Description •VSS The

HT7A6322 Flyback Configuration Low Cost Power Supply

AN0373E V1.20 1 / 16 March 1, 2018


D/N: AN0373E

Features

This switching power device has an isolated buck architecture and has the following

features.

• Wide operating voltage range

• Stable output voltage

• Under no-load conditions, the input power consumption is less than 100mW

• Over temperature protection

Typical System Characteristics

(Open Frame @ Room Temperature)

Description Wide Range (90VAC ~ 265VAC)

Input AC Frequency 47Hz~63Hz

Output Voltage (VOUT) 12VDC

Output Current (IOUT) 750mA(max)

Efficiency > 75% @ 115VAC，> 80% @ 230VAC

Standby Power Consumption < 0.1W @ 115VAC，< 0.1W @ 230VAC

Over Temperature Protection Yes


AN0373E V1.20 2 / 16 March 1, 2018

Application Circuit and Component List

VSS

FB

VCC

SW

SW

SW

SW

VSS

AC Cx2C1

Cs1

C4

C3

12V

C5

C7

C6

U1 HT7A6322

U2

U3

D1

D3

D2

D4

T1Rs1

R1

R2

R3

R4

R5

R6

R7

Ds

D5

D6

1234

8657

C2

F1

RT1

Cx1

CM1 Cs2Rs2

CM2

Rfb

Component Package Parameter Manufacturer C1 DIP EL 33µF/450V C2 DIP EL 330µF/50V C3 SMD1206 CE 100nF/50V C4 DIP EL 10µF/50V C5 SMD0805 CE 47nF C6 DIP Y-Capacitor 1nF/400V Cs1 SMD1206 2.2nF/1kV Cs2 SMD1206 1nF/1kV Cx1 DIP 0.1µF/1kV Cx2 (N.C) CM1 UU9.8 2x30mH common-mode line choke CM2 K5B T8x4x4 2x22µH common-mode line choke

D1,D2,D3,D4,Ds DO-41 1N4007, 1kV/1A D5 SMB GS1MF, 1kV/1A D6 DO-201AD STMicroelectronics BYW98-200 F1 DIP 1A/250VAC

RT1 Jump Wire R1 SMD0805 RES 4R7 R2 SMD0805 RES 4.7K R3 SMD0805 RES 220 R4 SMD0805 RES 1K R5 SMD0805 RES 9.1K R6 SMD0805 RES 15K R7 SMD0805 RES 6.2K Rfb SMD0603 RES 100 Rs1 SMD1206 100kΩ Rs2 SMD1206 30Ω T1 EF20 EF20, 3mH U1 DIP8 HT7A6322 Holtek U2 SOP-4 PC817 U3 TO-92 TL431


AN0373E V1.20 3 / 16 March 1, 2018

System Board Introduction

Top View

Bottom View

Functional Description The HT7A6322 is a highly functionally integrated device which uses an integrated PWM

controller with current mode control to drive an integrated high voltage power MOSFET.

Users can use either an isolated or non-isolated type architecture for system control

according to their requirements. In the isolated type architecture, the output signal is

transmitted to the primary side through a photo-coupler. However in the non-isolated

architecture the input side and the output side use the same ground. The output signal is

directly sent back to the HT7A6322 to implement output voltage driving. In addition, the

HT7A6322 operates with an excellent low standby current and uses the Burst Mode

function to achieve low system standby power consumption.

The HT7A6322 contains several system protection functions such as output short circuit

protection, IC over voltage protection and over temperature protection, etc. which ensure

that the system operates safely and with higher reliability.


AN0373E V1.20 4 / 16 March 1, 2018

Pin Description

• VSS The VSS pin is the power MOSFET source and the IC ground reference.

• FB This is the feedback input pin. It defines the peak inductor current that can pass through the integrated MOSFET. When the logic signal on the FB pin is “0”, it corresponds to the maximum peak inductor current. An FB resistor with the resistance of 100Ω is connected to prevent from aging and strengthen the reliability of operations in hostile environment.

• VCC The VCC pin is designed with a UVLO function. When the VCC voltage exceeds 14.5V (typ.), the HT7A6322 will start operation. When the VCC voltage is lower than 8V (typ.), the HT7A6322 will be turned off.

• SW The SW pin is connected to the drain of the integrated MOSFET. It is also used as an input pin for the internal high voltage start up JFET.

Transformer Design The T1 transformer specifications are as follows:

1

5

3

21 0.25mm X 86Ts

45 0.18mm X 52Ts

Need Gap:3pin - 1pin Lp=3mH

Transformer EF20 SPEC

1KHz/ 1V

2

4

12 0.25mm X 86Ts

Triple Insulated wire 97 0.22mm*2 X 46Ts

9

7

3 2

7

5

0.25mm x 43Ts

Tape 2Ts

Tape 1Ts0.25mm x 43Ts

Copper file 0.01t 1.2Ts

0.22mm*2 x 23Ts

0.22mm*2 x 23Ts

Tape 2Ts 9

2 0.25mm x 43Ts1 0.25mm x 43Ts

45 0.18mm x 52TsTape 2Ts

Tape 1Ts5 Copper file 0.01t 1.2Ts

Test Data Test Condition: Room Temperature

AC input voltage range: 90VAC ~ 265VAC，IOUT is 0A ~ 400mA (max.)

The AC input power consumption is for a no-load condition:

VAC (V) 90 115 135 180 230 265

Pin(W) 0.081 0.0835 0.085 0.0866 0.0877 0.0878

Vout(V) 12.24 12.24 12.24 12.24 12.24 12.24

Iout(mA) 0

System efficiency with different load conditions:

115VAC

Vout(V) 12.24 12.24 12.24 12.24 12.24 12.24 12.24 12.24 12.24 12.24 12.23 12.23 12.23 12.23

Iout(mA) 10.05 20.1 30.01 40.05 50.1 60.15 80.1 150.15 250.03 350.15 450.03 550.05 650.2 750.07

Pin(W) 0.253 0.414 0.566 0.72 0.875 1.027 1.328 2.406 3.755 5.29 6.763 8.285 9.855 11.527

η(%) 48.62 59.48 64.9 68.09 70.05 71.69 73.84 76.39 81.5 81.02 81.38 81.2 80.69 79.58

230VAC Vout(V) 12.24 12.24 12.24 12.24 12.24 12.24 12.24 12.24 12.24 12.24 12.23 12.23 12.23 12.23

Iout(mA) 10.05 20.1 30.01 40.05 50.1 60.15 80.1 150.15 250.03 350.15 450.03 550.05 650.2 750.07


AN0373E V1.20 5 / 16 March 1, 2018

Pin(W) 0.282 0.467 0.643 0.819 0.993 1.16 1.498 2.555 4.027 5.599 7.096 8.565 10.045 11.567

η(%) 43.62 52.65 52.65 57.13 59.83 61.75 65.43 71.93 76 76.55 77.56 78.54 79.16 81.42

AC Input Power Consumption -- No-load

System Efficiency -- Different Load Conditions

Output Voltage Stability -- Different Load Conditions

Standby Power

0.05

0.06

0.07

0.08

0.09

0.1

90 115 140 165 190 215 240 265

Vac(V)

Pin

(W)

Efficiency vs. Iout(mA)

0.00

10.00

20.00

30.00

40.00

50.00

60.00

70.00

80.00

90.00

0 150 300 450 600 750

Iout(mA)

Eff

icie

ncy(

%)

115V/60Hz

230V/50Hz

Vout(V) vs. Iout(mA)

11

11.2

11.4

11.6

11.8

12

12.2

12.4

12.6

12.8

13

0 150 300 450 600 750

Iout(mA)

Vou

t(V

)

115V/60Hz

230V/50Hz


AN0373E V1.20 6 / 16 March 1, 2018

SW Pin Voltage Waveform -- 115VAC, No-load Output

SW Pin Voltage Waveform -- 230VAC, No-load Output


AN0373E V1.20 7 / 16 March 1, 2018

SW Pin Voltage Waveform -- 115VAC, Full-load Output

SW Pin Voltage Waveform -- 230VAC, Full-load Output


AN0373E V1.20 8 / 16 March 1, 2018

Output Voltage Ripple -- 115VAC

Output Voltage Ripple -- 230VAC


AN0373E V1.20 9 / 16 March 1, 2018

Voltage Ripple -- 115VAC, Load-variant Output

Voltage Ripple -- 230VAC, Load-variant Output


AN0373E V1.20 10 / 16 March 1, 2018

Output Voltage Waveform -- 115VAC, No-load Start Up

Output Voltage Waveform -- 230VAC, No-load Start Up


AN0373E V1.20 11 / 16 March 1, 2018

Output Voltage Waveform -- 115VAC, Full-load Start Up

Output Voltage Waveform -- 230VAC, Full-load Start Up


AN0373E V1.20 12 / 16 March 1, 2018

Output Voltage Waveform -- 115VAC, No-load Shut Down

Output Voltage Waveform -- 230VAC, No-load Shut Down


AN0373E V1.20 13 / 16 March 1, 2018

Output Voltage Waveform -- 115VAC, Full-load Shut Down

Output Voltage Waveform -- 230VAC, Full-load Shut Down


AN0373E V1.20 14 / 16 March 1, 2018

Conduction Measurement -- 115VAC, Full-load

Conduction Measurement -- 230VAC, Full-load


AN0373E V1.20 15 / 16 March 1, 2018

Radiated Measurement -- 110VAC, Full-load

Radiated Measurement -- 230VAC, Full-load

Versions and Revision

Date Author Issue and Revision Note

2015.04.16 詹作晟 V1.00, First version.

2015.06.04 詹作晟 Version 1.10. The application circuit was modified.

2018.02.12 陳佳宏 Version 1.20 updated contents: 1. Application Circuit and Component List 2. The figures and FB pin description of the System

Board Introduction section.

Reference Files

Reference file: HT7A6322 Data Sheet.

For more information, refer to the Holtek official website www.holtek.com.

http://www.holtek.com/


AN0373E V1.20 16 / 16 March 1, 2018

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Documents

HT7A6322 Flyback Configuration Low Cost Power Supply · HT7A6322 Flyback Configuration Low Cost Power Supply . AN0373E V1.20 1 / 16 March 1, 2018 . ... Pin Description •VSS The