SC1631 Semtech Corporation, SC1631 Datasheet - Page 7

• Manufacturer Part Number: SC1631
• Description: LOW VOLTAGE STEP-UP DC-DC CONVERTER
• Manufacturer: Semtech Corporation

January 29, 1998
DEVICE OUTLINE - SO-8
PIN DESCRIPTIONS
PIN 1: I
PIN 2: V
PIN 3: SW
PIN 4: SGND Ground connected to the source of the
© 1997 SEMTECH CORP.
LIM
IN
/SD (1) Connected to V
sistor to set the switch peak current. It
serves to protect the IC and inductor,
as well as to improve efficiency and
output ripple. However, the supply ca-
pability of the SC1631 is limited by the
current limit resistor (see typical per-
formance characteristics). The I
pin should be shorted to V
switch peak current is not required.
(2) The SC1631 goes into shutdown
mode and consumes less than 10µA
when the I
ground.
Input supply.
Drain of the power switch, to be con-
nected to the inductor and diode.
power switch.
LIM
/SD pin is pulled to
IN
pin through a re-
IN
LOW VOLTAGE STEP-UP
DC-DC CONVERTER
if limiting
LIM
/SD
PIN 5: CGND Ground for control circuits of the IC. It
PIN 6: LBO
PIN 7: LBI
PIN 8: V
PIN CONFIGURATION
652 MITCHELL ROAD NEWBURY PARK CA 91320
OUT
should be separated from SGND to
avoid interference.
Open drain output of the battery low
detector, with 45 Ohm “On Resis-
tance” at V
the voltage on the LBI pin is below
1.22 volts.
The inverting input of the battery low
detector, of which the non-inverting
input is internally connected to the
1.22V voltage reference.
The output voltage feeds back to the
IC through this pin.
IN
=2V. It is pulled low when
SC1631