MB3788
4
■
■■
■
BLOCK DIAGRAM
24
Channel 1
-IN1 (E)
FB1
-IN1 (C)
+IN1 (E)
1
2
5
4
Ca1
V
CC(out)
OUT1
Cb1
11
13
14
3
CTL2
V
CC
CTL1
VE1
10 12
GND
-IN(PWM)
SCP
V
REF
1.9 V
1.3 V
+
-
+
-
+
-
1.5 V
0.6 V
Error amplifier 1
Comparator 1
PWM comparator 1
OFF current setting
23
21
20
22
Channel 2
-IN2 (E)
FB2
-IN2 (C)
+IN2 (E)
Cb2
OUT2
Ca2
VE2
+
-
+
-
1.5 V
0.6 V
Error amplifier 2
Comparator 2
PWM comparator 2
OFF current setting
-
-
+
SCP comparator
2.1 V
Low input
voltage
protection
circuit
SR latch
circuit
Reference
voltage
power (2.5 V)
Power/channel
ON/OFF
circuit
Timer circuit
1 µA
VREF
+
-
15
9
7
6
8
16
18
19
17