FAN5233 Datasheet, PDF (3/15 Pages) Fairchild Semiconductor – System Electronics Regulator for Mobile PCs

PRODUCT SPECIFICATION
FAN5233
Pin Description (Continued)
Pin Name
LSD3.3
GND3.3
ISEN3.3
VFB3.3
SDN3.3
PGOOD
SDWN
SGND
VFB12
SW12
SDN5
VFB5
GND5
LSD5
ISEN5
SW5
HSD5
CPUMP5
Pin Number Pin Function Description
7
Low-side gate driver for 3.3V. Connect this pin directly to the gate of an
N-channel MOSFET. The trace from this pin to the MOSFET gate should be < 1".
8
Ground for 3.3V MOSFET.
9
Current sense for 3.3V. This pin should be connected to the Drain of the bottom
Mosfet with an appropriate resistor and an RC filter. See Application Section.
10
Voltage feedback for 3.3V.
11
Soft Start and ON/OFF for 3.3V. OFF=GND. ON=open with SDWN=High. Use
open collector device for control.
12
Power Good Flag. An open collector output that will be logic low if any output
voltage is not above 89% of the nominal output voltage.
13
Master Shutdown. Shutdown for all power. Off when low. When high
5V/3.3V-ALWAYS are ON while 5V/3.3V-Main are ready to turn on if SDN5,
SDN3.3 go open.
14
Signal ground.
15
Voltage feedback for 12V.
16
FET driver for 12V Boost.
17
Enable/Soft Start for 5V and 12V. Soft start and ON/OFF for 5V & 12V.
OFF=Grounded. ON=open with SDWN=High.
18
Voltage feedback for 5V.
19
Ground for 5V MOSFET.
20
Low side FET driver for 5V. Connect this pin directly to the gate of an N-channel
MOSFET. The trace from this pin to the MOSFET gate should be < 1".
21
Current Sense for 5V. This pin should be connected to the drain of the bottom
Mosfet using appropriate resistor and RC filter. See Application Section.
22
High Side Driver Source and Low Side Driver Drain Switching Node.
Switching node for 5V.
23
High side FET driver for 5V. Connect this pin directly to the gate of an N-channel
MOSFET. The trace from this pin to the MOSFET gate should be < 1".
24
Charge Pump 5V. High side Gate drive voltage for 5V. High side Gate drive
voltage for 5V. This pin is to be connected to SW5 through a 100nF cap. and to
5V-ALWAYS through a diode.
REV. 1.0.6 1/22/02
3