SC2422 Semtech Corporation, SC2422 Datasheet - Page 4

• Manufacturer Part Number: SC2422
• Description: BIPHASE CURRENT MODE CONTROLLER
• Manufacturer: Semtech Corporation

PRELIMINARY - August 7, 2000
PIN DESCRIPTION
Pin 1: VID4 , MSB
Pin 2: VID3
Pin 3: VID2
Pin 4: VID 1
Pin 5: VID0 , LSB
Pin 6: ERROUT Error-amplifier output.
Pin 7: FB Error-amplifier inverting input.
Pin 8: RREF Frequency setting resistor pin. Also pro-
grams the DAC current step size. (see application in-
formation for programming the frequency)
Pin 9: GND Chip ground.
Pin 10: UVLO Programmable Under Voltage Lock-
Out. This pin may be connected to the MOSFET driver
supply through a voltage divider to inhibit the SC2422A
until the drivers are on. The UVLO comparator trip
point is 1.5V.
Pin 11: OC- Input current sense, negative input. This
pin is connected to the input supply side of the current
PIN CONFIGURATION
© 2000 SEMTECH CORP.
(16-Pin SOIC)
Top View
BIPHASE CURRENT MODE
CONTROLLER
FUNCTIONAL BLOCK DIAGRAM
sense resistor.
Pin 12: OUT2 PWM output for phase 2. Drives exter-
nal Power MOSFET driver.
Pin 13: OUT1 PWM output for phase 1. Drives exter-
nal Power MOSFET driver.
Pin 14: OC+ Input current sense positive input. This
pin is connected to MOSFET side of the current sense
resistor.
Pin 15: BGOUT Soft start and reference. Bypass to
ground (GSEN) with a .022µF - 0.1µF capacitor to im-
plement soft start in conjunction with internal 3K re-
sistor. To ensure output voltage accuracy, the maxi-
mum current source/sink from this pin should be lim-
ited to 0.5 uA.
Pin 16: VCC Chip positive supply.
652 MITCHELL ROAD NEWBURY PARK CA 91320
SC2422A
4