SP690 SIPEX [Sipex Corporation], SP690 Datasheet - Page 4

• Manufacturer Part Number: SP690
• Description: Low Power Microprocessor Supervisory with Battery Switch-Over
• Manufacturer: SIPEX [Sipex Corporation]

Figure 10. Pinout
PIN ASSIGNMENTS
Pin 1 —V
Pin 2 — V
Pin3 — GND — Ground reference for all signals
Pin 4 — PFI — Power-Fail Input. This is the
Pin 5 — PFO — Power-Fail Output.
Pin 6 — WDI — Watchdog Input. WDI is a
Pin 7 for SP690A/692A/802 only — RESET
SP690A/692ADS/08
GND
V
V
PFI
OUT
CC
connects to V
V
old. When V
V
connects to V
capacitor from V
noninverting input to the power-fail com-
parator. When PFI is less than 1.25V,
PFO goes low. Connect PFI to GND or
V
three level input. If WDI remains high or
low for 1.6sec, the internal watchdog timer
triggers a reset. If WDI is left floating or
connected to a high-impedance tri-state
buffer, the watchdog feature is disabled.
The internal watchdog timer clears when-
ever reset is asserted.
(Active Low)– Reset Output. RESET Out-
put goes low whenever V
the reset threshold or whenever WDI
remains high or low longer than 1.6
seconds. RESET remains low for 200ms
after V
voltage on power-up or after being trig-
gered by WDI.
BATT
CC
OUT
2
1
3
4
OUT
CC
is below the reset threshold, V
when not used.
and V
— Output Supply Voltage. V
CC
— +5V Supply Input
crosses the reset threshold
SP690A/692A Low Power Microprocessor Supervisory with Battery Switch-Over
CC
CC
CC
BATT
is above the reset thresh-
when V
falls below V
OUT
8
7
6
5
. Connect a 0.1 F
*( ) SP805 only
to GND.
RESET (RESET)*
V
PFO
WDI
BATT
CC
CC
is greater than
falls below
BATT
OUT
and
OUT
4
Figure 11. Internal Block Diagram
Pin 7 for SP805 only — RESET (Active High)–
Pin 8 — V
V
WDI
PFI
V
BATT
CC
Reset Output is the inverse of RESET;
when RESET is asserted, the RESET
output voltage = V
whichever is higher.
V
will be switched to V
20mV greater than V
20mV above V
reconnected to V
hysteresis prevents repeated switching if
V
BATTERY-SWITCHOVER
3.5V
CC
CC
BATT
falls below the reset threshold, V
falls slowly.
CIRCUITRY
1.25V
0.8V
— Backup-Battery Input. When
1.25V
© Copyright 2000 Sipex Corporation
*( ) SP805 only
GENERATOR
BATT
WATCHDOG
TIMER
RESET
CC
CC
CC
, V
. When V
OUT
.
OUT
The 40mV
or V
if V
(RESET)*
will be
RESET
BATT
CC
BATT
V
PFO
OUT
BATT
rises
is
,