Philips DVDR615 Service Manual page 161

http://www.jdwxzlw.com/?fromuser=华盛维修
Circuit-, IC descriptions and list of abbreviations
IC7929 NCP1570D, FEBE Board, DC/DC Converter Control
UVLO COMP
V
–
CC
+
+
8.5 V/7.5 V
–
GND
V –
FB
+
+
0.985 V
–
COMP
0.525 V
Σ
– +
–
+
+
0.89 V/0.69 V
–
PACKAGE PIN #
SO–8
1
2
3
4
5
6
7
8
家电维修资料网，免费下载各种维修资料
–
+
+
0.25 V
–
Error Amp
PWM COMP
+
–
OSC
Art Ramp
80%, 200 kHz
+
0.25 V
–
PGDELAY Latch
S Q
R
Set Dominant
Figure 9-34
PACKAGE PIN DESCRIPTION
PIN SYMBOL
V
CC
PWRGD
PGDELAY
COMP
GATE(H)
GATE(L)
V
FB
GND
Figure 9-35
DVDR615/69
Fault Latch
S Q
R
Set Dominant
PWM Latch
R Q
S
Reset Dominant
+
–
+
3.3 V
–
FUNCTION
Power supply input.
Open collector output goes low when V
must externally limit current into this pin to less than 20 mA.
External capacitor programs PWRGD low–to–high transition delay.
Error amp output. PWM comparator reference i nput. A capacitor to
LGND provides error amp compensation and S
< 0.45 locks gate outputs to a zero percent duty cycle state.
High–side switch FET driver pin. Capable of delivering peak currents
of 1.5 A.
Low–side synchronous FET driver pin. Capable of delivering peak
currents of 1.5 A.
Error amplifier and PWM comparator i
Power supply return.
9.
V
CC
GATE(H)
Non
Overlap
GATE(L)
12 µA
PGDELAY
PWRGD
–
+
is out of regulation. User
FB
oft Start. Pulling pin
nput.
EN 161