LB1975
Duty – VCTL characteristics
100
80
60
40
20
0
VCTL1
VCTL2
Control voltage, VCTL — V
Block Diagram and Peripheral Circuit
VREG
S/S F/R
FG1 FG2
VCC
VCC
Reg
+
Hys.Amp
+
IN1 –
+
IN2 –
Logic
LVSD
TSD
+
VM
VM
OUT1
OUT2
OUT3
VCTL
+
+
IN3 –
31 kΩ
VCTL 40 kΩ VCTL Amp
–
+
2.35 V
PWM
OSC
VCREF VCOUT
OSC
Current
limiter
RF
Rf
0.5 V
GND1 GND2 GND3
A11952
No. 6087-5/12