Service manual

FSD20X-SERIES
2
Preliminary Specification
Absolute Maximum Ratings
(Ta=25°C unless otherwise specified)
PIN Definitions
Parameter Symbol Value Unit
Maximum Drain Voltage V
D,MAX
700 V
Maximum Vstr Pin Voltage V
str,max
700 V
Continuous Drain Current (T
C
=25°C) I
D,
FSD200 0.5 A
DC
Continuous Drain Current (T
C
=25°C) I
D,
FSD201 1.0 A
DC
Maximum Supply Voltage V
CC,MAX
20 V
Input Voltage Range V
FB
−0.3 to V
start
V
Operating Ambient Temperature T
A
−25 to +85 °C
Storage Temperature Range T
STG
−55 to +150 °C
Pin Number Pin Name Pin Function Description
1, 2, 3 GND These pins are the control ground and the SenseFET Source.
4Vfb
This pin is the inverting input of the PWM comparator, and it operates
normally between 0.5V and 2.5V. It has a 0.25mA current source connected
internally and a capacitor and opto coupler connected externally. A
feedback voltage of 3V to 4V triggers overload protection (OLP). There is a
time delay due to the 5uA current source, which prevents false triggering
under transient conditions but still allows the protection mechanism to
operate under true overload conditions.
5Vcc
This is the positive supply voltage input. During operating, power is supplied
from pin1, Vstr and the voltage is regulated by internal HV/reg (7V shunt
regulator). The Auxiliary transformer winding is not needed.
7Drain
This pin is designed to directly drive the converter transformer and is
capable of switching a maximum of 700V.
8Vstr
This pin connects directly to the rectified AC line voltage source. At start up
the internal switch supplies internal bias and charges an external capacitor
that connects from the Vcc pin to ground. once V
CC
reaches 7V, then FPS
operates, and Trferal HV/REG regulates 7V of V
CC
.
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