CS2516
CS2516
Pulse-Load Battery Monitor
Description
The CS2516 is designed for use in bat-
tery powered medical, security, or
environmental systems where prior
notification of impending power
source failure is a requirement. The IC
effectively provides continuous moni-
toring of battery condition by pulse-
sampling the system voltage at prede-
termined intervals. Low standby cur-
rent permits unswitched connection to
the battery with minimal impact on
operating life. The ability to load the
battery during the test pulse provides
assurance that sufficient reserve capac-
ity exists to operate critical system
components.
The CS2516 contains an internal timer
that generates a 1.0 millisecond test
pulse once each 33 seconds (both times
are typical). The load switch transistor
conducts only during the test pulse,
and can sink up to 50mA directly. An
external transistor can be added to in-
crease the load current capability.
Should, during the test pulse, the sense
terminal voltage fall below the thresh-
old level determined by the internal
(synthesized) temperature compensat-
ed zener diode, the comparator will
permit a charging current to flow out
of PW. This pin is also the input of a
Schmitt trigger that in turn drives the
output transistor. Collectively, the
charge current and trigger, in conjunc-
tion with an external RC network,
operate as a Òpulse-stretcherÓ to pro-
vide output ÒONÓ times that are a
multiple of the sampling time. This
feature permits low battery alarm
devices or visible annunciators to be
driven directly by the IC. The maxi-
mum permissible output current is
30mA.
Features
s
Adjustable Battery Sense
from 7 to 12 Volts
s
Pulse Loads Battery at up
to 50mA
s
Standby Current Under
10µA
s
Test Period, Rate and Load
Adjustable
s
On Chip 15mA Output
Driver
Block Diagram
Package Options
8L PDIP and 8L SO
R
p
V
CC
R
P
1
SENSE
2
C
T
3
8
7
6
5
V
CC
PW
OUT
Load
Switch
SENSE
PW
COM
4
C
T
Cycle
Timer
OUT
COM
Load Switch
Cherry Semiconductor Corporation
2000 South County Trail, East Greenwich, RI 02818
Tel: (401)885-3600 Fax: (401)885-5786
Email: info@cherry-semi.com
Web Site: www.cherry-semi.com
Rev. 1/17/95
1
A
¨
Company
CHERRY [ CHERRY SEMICONDUCTOR CORPORATION ]
