isl97656 Intersil Corporation, isl97656 Datasheet - Page 3

• Manufacturer Part Number: isl97656
• Description: 640khz/1.2mhz Pwm Step-up Regulator
• Manufacturer: Intersil Corporation

Pin Descriptions
Block Diagram
Typical Application Circuit
PIN NUMBER
4, 5
6, 7
10
1
2
3
8
9
PIN NAME
COMP
FREQ
GND
IN
FB
EN
SS
LX
IN
4.7nF
3
3.9kΩ
GENERATOR
REFERENCE
C
R
5
3
Compensation pin. Output of the internal error amplifier. Capacitor and resistor from COMP pin to ground.
Voltage feedback pin. Internal reference is 1.24V nominal. Connect a resistor divider from V
V
Shutdown control pin. Pull EN low to turn off the device.
Analog and power ground.
Power switch pin. Connected to the drain of the internal power MOSFET.
Analog power supply input pin.
Frequency select pin. When FREQ is set low, switching frequency is set to 620kHz. When connected to
high or IN, switching frequency is set to 1.25MHz.
Soft-start control pin. Connect a capacitor to control the converter start-up.
OUT
COMPARATOR
COMP
= 1.24V (1 + R
R
1
10kΩ
86.6kΩ
R
2
OSCILLATOR
1
FREQ
1
2
3
4
5 GND
AMPLIFIER
CURRENT
/R
SENSE
COMP
FB
EN
GND
2
ISL97656
GM
). See “Typical Application Circuit” on page 3.
CONTROLLER
PWM LOGIC
FREQ
LX
SS
LX
IN
10
9
8
7
6
AND START-UP
EN
SHUTDOWN
CONTROL
DESCRIPTION
C
27nF
C
0.1µF
SS
3
4
DRIVER
+
FET
C
22µF
1
10µH
D
1
2.3V TO 5.5V
+
22µF
C
2
LX
GND
FB
12V
September 10, 2007
OUT
.
FN6439.0