CMOS IC
For Switching Power Supply Control
FA551X series
FA551X
FA5510P (N), FA5511P (N)
FA5514P (N), FA5515P (N)
■ Dimensions, mm
ꢀ SOP-8
5
8
■ Description
The FA551X series are the PWM type switching power supply
control ICs that can directly drive power MOSFET. These ICs
use a CMOS device with high dielectric strength (30V) to
implement low power consumption. These ICs contain many
function in a small 8-pin package. With these ICs, a high-
performance and compact power supply can be created
because not many external discrete components are needed.
1
4
4.9
■ Features
• Low current consumption by CMOS process with high
dielectric strength (30V)
0.4±0.1 1.27
• Standby current of 2µA or less (at Vcc=14V), and operating
current of 1.5mA (typ)
• Overvoltage protection function detecting the Vcc voltage
• A drive circuit for connecting a power MOSFET directly
• Output peak current: ±1.5A
ꢀ DIP-8
8
5
• Pulse-by-pulse overcurrent limiting function
• Overload protection function (latch or non-latch mode selectable)
• Output ON-OFF function by external signal
• Latch-mode overvoltage shutdown function
• Undervoltage lockout function (16.5V ON / 9V OFF)
• Reference voltage output (5V)
4
1
9.3
1.5±0.3
• 8-pin package (DIP/SOP)
■ Block diagram
7.62
ꢀ FA5510P (N), FA5511P (N)
2.54
0.46±0.1
VCC(6)
UVLO
CS(8)
REF
(7)
5.2µA
15.5V
15.5V
0.8V/0.68V
5V VCC
0.95mA
ENB
5V REF
8.5V/7.9V
4V
16.5V/9V
0.8V
Pin Pin
No. symbol
Function
Description
OUT
(5)
3.5V
ENB
FB
(2)
1
RT
Oscillator timing
resistor
Setting oscillation frequency
Input of PWM comparator
OUT
PUT
PWM
2
3
FB
IS
Feedback
Dmax
FA5510: 46%
FA5511: 70%
GND
(4)
OSC
RT CT
Overcurrent
detection
Input of the overcurrent
limiting function
R
S
QB
+0.24V
Q
4
5
GND
OUT
Ground
Output
Ground
FF
5V Controlled block
Output for driving a power
MOSFET
RT(1)
IS+(3)
6
7
8
VCC
REF
CS
Power supply
Power supply
Reference voltage Reference voltage output (5V)
ꢀ FA5514P (N), FA5515P (N)
Soft-start and
ON/OFF control
Soft-start, ON/OFF function and
latch-mode shutdown operations
VCC(6)
CS(8)
REF
(7)
5.2µA
15.5V
15.5V
0.8V/0.68V
5V VCC
0.95mA
UVLO
ENB
Type
Max. duty
cycle (typ.) detection
Polarity of overcurrent Package
5V REF
8.5V/7.9V
16.5V/9V
ENB
FA5510P
FA5510N
FA5511P
FA5511N
FA5514P
FA5514N
FA5515P
FA5515N
46%
70%
46%
70%
+
+
–
–
DIP-8
SOP-8
DIP-8
SOP-8
DIP-8
SOP-8
DIP-8
SOP-8
0.8V
OUT
(5)
3.5V
FB
(2)
4V
OUT
PUT
PWM
Dmax
FA5514: 46%
FA5515: 70%
GND
(4)
OSC
R
S
RT CT
QB
Q
-0.17V
FF
5V Controlled block
RT(1)
IS-(3)
1