SC1401 Semtech Corporation, SC1401 Datasheet - Page 2

• Manufacturer Part Number: SC1401
• Description: HIGH PERFORMANCE SYNCHRONOUS BUCK CONTROLLER WITH LDO FOR PORTABLE POWER
• Manufacturer: Semtech Corporation

November 21, 2000
Note: All logic level inputs and outputs are open collector TTL compatible.
© 2000 SEMTECH CORP.
Pin #
10
11
12
13
14
15
16
17
18
19
20
1
2
3
4
5
6
7
8
9
SYNC
SHDN
FB
VDD1
GND
CSL
CSH
V5V
DL
PGND
PGND
PHASE
DH
BST
VDD2
GATEIO
IOS
ENABLEIO
RESET
PSAVE
Pin Name
Pin Function
Oscillator control/synchronization input. Connect to V5V for 300kHz. Connect to
GND for 200kHz. For external clock synchronization in the 240kHz to 350kHz
range. A high-to-low transition causes a new cycle start.
Logic Low shuts down the switching regulator.
Feedback input for the SMPS. FB selects fixed 1.25V output voltage setting
when tied to V
Supply input from battery (6V to 30V).
Low noise analog ground and feedback reference point.
Inverting input to current sense amplifier. Also serves as the feedback input in
fixed output mode.
Non-Inverting input to current sense amplifier. Current limit level is 120mV
referenced to CSL.
5 volt external supply used to power the gate drives, internal control and
reference of the SC1401.
Gate drive output for low side synchronous rectifier MOSFET.
Device power ground.
Device power ground.
Inductor switching node connected to the source of high side MOSFET
and drain of low side MOSFET.
Gate drive output for high side N-Channel MOSFET. DH is a floating driver
output driven from the floating voltage across BST to PHASE.
Boost capacitor connection for the high side driver.
Supply voltage input for the linear FET controller.
Gate drive output for the linear FET controller.
Sense input voltage for the adjustable voltage linear FET controller.
Logic low shuts down the linear FET controller.
Active-Low reset output.
A logic low enables power saving mode.
V
V
O
O
(SMPS)
(Linear)
HIGH PERFORMANCE SYNCHRONOUS BUCK
CONTROLLER WITH LDO FOR PORTABLE
POWER
1.25
1.25
OUT
. Connect FB to a resistor divider for adjustable output mode.
1
1
R
R
R
R
8
9
5
6
652 MITCHELL ROAD
Refer to page 9.
Refer to page 9.
NEWBURY PARK CA 91320
PIN DESCRIPTION
SC1401
2