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- 19 –
ViewSonic Corporation
Confidential - Do Not Cop
VA1721wmb
Circuit Diagram
LD7552BPS (IC901):
PWM control, high-voltage startup current. The circuit unit has
functions such as over-current protection, over-voltage protection, output short-circuit
protection and etc. The function of each pin and the inside circuit diagram are as
follows
:
Pin
Name
Function
1 GND Ground
2 COMP
Voltage feedback pin (same as the COMP pin in UC384X), By
connecting a photo-coupler to close the control loop and achieve the
regulation
3
VCC Supply voltage pin
4 RT
This pin is to program the switching frequency. By connecting a resistor
to ground to set the switching frequency.
6 NC
Unconnected
pin
7
VCC Supply voltage pin
8
OUT Gate drive output to drive the external MOSFET
Summary of Contents for VA1721wmb - 17" LCD Monitor
Page 22: ...22 ViewSonic Corporation Confidential Do Not Cop VA1721wmb Block Diagram...
Page 36: ...36 ViewSonic Corporation Confidential Do Not Cop VA1721wmb...
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Page 41: ...41 ViewSonic Corporation Confidential Do Not Cop VA1721wmb 5 7 Packing Procedure...
Page 42: ...42 ViewSonic Corporation Confidential Do Not Cop VA1721wmb 6 Troubleshooting Flow Chart...
Page 56: ...56 ViewSonic Corporation Confidential Do Not Cop VA1721wmb Packing For Shipping...
Page 60: ...60 ViewSonic Corporation Confidential Do Not Cop VA1721wmb Picture 19...
Page 61: ...61 ViewSonic Corporation Confidential Do Not Cop VA1721wmb 10 Block Diagram...
Page 71: ...71 ViewSonic Corporation Confidential Do Not Cop VA1721wmb 12 2 MAIN BOARD PCB BUTTON VIEW...
Page 72: ...72 ViewSonic Corporation Confidential Do Not Cop VG1721wm VA1721wm 12 3 POWER PCB TOP VIEW...
Page 73: ...73 ViewSonic Corporation Confidential Do Not Cop VG1721wm VA1721wm 12 4 POWER PCB BUTTON VIEW...
Page 75: ...75 ViewSonic Corporation Confidential Do Not Cop VA1721wmb 12 7 POWER PCB TOP BUTTON VIEW Q...