S-8327 Seiko, S-8327 Datasheet - Page 24

• Manufacturer Part Number: S-8327
• Description: (S-8323 / S-8327) SMALL PACKAGE PWM CONTROL STEP-UP SWITCHING REGULATOR
• Manufacturer: Seiko

V
7. LCD Power Supply (Standard circuit (6))
IN
When output current I
supply and the IC may be broken. Select a large current capacitance transistor.
The start circuit is not needed because the power supply is supplied from V
The output voltage cannot be changed with external resistors.
Set R
efficiency to be improved. On the other hand, the switching loss of the Tr becomes large and consequently the efficiency will
be worsened. Select R
The following are an application power supply circuit (30V/5mA) for intermidiate and large size LCD, and its characteristics
when 3V (3V±10%) and 5V (5V±10%) are used for the applied power.
10mV/div
CONT
(2V/div)
Output
Voltage
C
b
IN
to 60
-3V
0V
+
-
(c) Ripple Characteristics
or more and R
SMALL PACKAGE PWM CONTROL STEP-UP SWITCHING REGULATOR
CD54/100 H
OUT
E
L
to ensure high efficiency under operating conditions.
t (10 sec/div)
exceeds 50 mA, the current capacitance in the external transistor 2SA1362 becomes in short
E
to 6 k
Figure 26
or less. The larger R
0.022 F
Cb
Seiko Instruments Inc.
1k
R
b
EXT
V
Figure 27
DD
MA720
SD
S-8327E50
E
, the smaller the reactive current through R
V
S
V
OUT
DD
to the IC. Set Vin to 9 V - |V
C
C
15pF 482k
R
R
B
A
100k
C
OUT
S-8323/8327 Series
+
-
4.7 F/50V 2
F93
E
and R
CC
| or less.
b
, allowing the
to 30V
23