SP703 Datasheet, PDF (4/16 Pages) Sipex Corporation – Low Power Microprocessor Supervisory with Battery Switch-Over

PINOUT
VOUT ¹
VCC ²
GND 3
PFI 4
8 _VBATT
7 RESET
6 MR
5 PFO
INTERNAL BLOCK DIAGRAM
VBATT ^{BATTERY SWITCHOVER}
CIRCUITRY
VOUT
VCC
RESET
RESET
GENERATOR
1.25V
MR
PIN ASSIGNMENTS
Pin 1 —V_OUT — Output Supply Voltage. V_OUT
connects to V_CC when V_CC is greater than
V_BATT and V_CC is above the reset thresh-
old. When V_CC falls below V_BATT and
V_CC is below the reset threshold, V_OUT
connects to V_BATT. Connect a 0.1µF ca-
pacitor from V_OUT to GND.
Pin 2 — V_CC — +5V Supply Input
Pin3 — GND — Ground reference for all signals
Pin 4 — PFI — Power-Fail Input. This is the
noninverting input to the power-fail com-
parator. When PFI is less than 1.25V,
PFO goes low. Connect PFI to GND or
V_OUT when not used.
Pin 5 — PFO — Power-Fail Output.
Pin 6 — MR — Manual Reset Input. This input
generates a reset pulse when pulled below
0.8V. This active LOW input is TTL/
CMOS compatible and can be shorted to
ground with a switch. It has an internal
250µA (typical) pull-up current. Leave
this pin floating when not used.
Pin 7 — RESET (Active Low)– Reset Output.
RESET Output goes low whenever
V_CC falls below the reset threshold or
whenever MR is pulled below 0.8V for
longer than 150nS. RESET remains low
for 200ms after V_CC crosses the reset
threshold voltage on power-up or after
being triggered by MR.
PFI
1.25V
PFO
Pin 8 — V_BATT — Backup-Battery Input. When
V_CC falls below the reset threshold, V_BATT
will be switched to V_OUT if V_BATT is
20mV greater than V_CC. When V_CC rises
20mV above V_BATT, V_OUT will be recon-
nected to V_CC. The 40mV hysteresis pre-
vents repeated switching if V_CC falls
slowly.
SP703/704DS/07
SP703/704 Low Power Microprocessor Supervisory
4
© Copyright 2000 Sipex Corporation