Datasheet CS2516KD8, CS2516KN8, CS2516KDR8 Datasheet (Cherry Semiconductor)

Features

■

Adjustable Battery Sense
from 7 to 12 Volts

■

Pulse Loads Battery at up
to 50mA

■

Standby Current Under
10µA

■ Test Period, Rate and Load

Adjustable

■ On Chip 15mA Output

Driver

Package Options

8L PDIP and 8L SO

CS2516

Pulse-Load Battery Monitor

CS2516

Description

The CS2516 is designed for use in bat­tery powered medical, security, or
environmental systems where prior
notification of impending power
source failure is a requirement. The IC
effectively provides continuous moni­toring of battery condition by pulse­sampling the system voltage at prede­termined intervals. Low standby cur­rent 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 capac­ity 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 in­crease the load current capability.

Should, during the test pulse, the sense
terminal voltage fall below the thresh­old level determined by the internal
(synthesized) temperature compensat­ed 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 conjunc­tion with an external RC network,
operate as a Òpulse-stretcherÓ to pro­vide 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 maxi­mum permissible output current is
30mA.

Block Diagram

1

Cherry Semiconductor Corporation

2000 South County Trail, East Greenwich, RI 02818

Tel: [phone] Fax: [phone]

Email: [e-mail]

Web Site: www.cherry-semi.com

A Company

¨

Rev. 1/17/95

R

SENSE

C

COM

V

CC

PW

OUT

Load Switch

1

R

P

SENSE

2

3

C

T

4

COM

8

7

6

5

V

CC

PW

OUT

Load

Switch

p

T

Cycle
Timer

2

Electrical Characteristics: VCC= 9V, Rp= 9.1 M½, CT= 4.7µF, Cpw = 0.1µF, Rpw = 10M½,

0¡²TA² 85¡ unless otherwise specified.

PARAMETER TEST CONDITIONS MIN TYP MAX UNIT

Absolute Maximum Ratings

Supply Voltage (VCC).........................................................................................................................................................0 to 14V

RpInput Voltage ............................................................................................................................................................-0.5 to V

CC

SENSE, CT, PW, Output and Load Switch....................................................................................................................-0.5 to 8V

Load Current...........................................................................................................................................................................50mA

Output Current ......................................................................................................................................................................30mA

Storage Temperature.................................................................................................................................................-40 to +150ûC

Lead Temperature Soldering: Wave Solder (through hole styles only)..........................................10 sec. max, 260¡C peak

Reflow (SMD styles only) ..........................................60 sec. max above 183¡C, 230¡C peak

CS2516

■ V

CC

Operating Voltage 9 12 V
Standby Current 4 10 µA

■ Cycle Timer

Charge Current V

C

T

=0V, 6V²VCC²12V -1.70 -1.20 -0.48 µA

2V ² V

C

T

< 7.5V -0.77 -0.74 -0.71 µA

Discharge Current V

C

T

= 8.8V 8.0 20.0 25.0 mA

V

C

T

= 2.0V 1.1 3.0 3.6 mA

Discharge Impedance 4.6V < V

C

T

< 8.0V 440 ½

Upper Charge Threshold -0.48µA < I

C

T

< -1.70µA 7.0 8.0 9.0 V
Lower Charge Threshold -0.48µA < IC< -1.70µA 0.5 1.0 3.0 V
Lower Discharge Threshold 1.1mA < IC< 25mA 2.0 4.6 6.0 V

■ Load Switch

ÒONÓ Voltage I

Load Switch

= 50mA 0.3 0.5 V

ÒOFFÓ Current V

Load Switch

= 12V 1.0 µA

■ Sense Input

Threshold Voltage 6.3 6.7 7.1 V
Threshold Temp Coefficient 0¡C < TA< 85¡C 150 ppm/¡C
Active Impedance 5.0 8.5 12.0 k½

■ Pulse Stretcher

Source Current V

SENSE

= 6.3V, VPW= 0V -950 -550 -250 µA

V

CC=VSENSE

=6.3V, VPW= 0V -300 -250 -200 µA
Schmitt Upper Threshold 2.25 2.50 2.75 V
Hysteresis 0.60 1.00 1.40 V
Input Bias Current V

SENSE

=7.1V, VPW=1.2V 1.00 µA

■ Output Switch

ÒONÓ Voltage VPW= 3V; I

OUT

= 15mA 0.1 0.5 V

ÒOFFÓ Current V

PW

= 0V; V

OUT

= 12V 1.0 µA

3

Package Pin Description

PACKAGE PIN # PIN SYMBOL FUNCTION

Typical Performance Characteristics

Timing Diagram

CTDischarge Impedance vs CTVoltage (Typ +25¡C)

Electrical Characteristics: VCC= 9V, RP= 9.1 M½, CT= 4.7µF, Cpw = 0.1µF, Rpw = 10M½,

0¡²TA² 85¡ unless otherwise specified

PARAMETER TEST CONDITIONS MIN TYP MAX UNIT

CS2516

8L PDIP & SO Narrow

1RPTest period programming resistor.

2 SENSE Voltage sense comparator input.

3CTTest period, duration programming capacitor.

4 COM Common negative

5 Load Switch Collector of pulse loading NPN transistor.

6 OUT Alarm Pulse width-stretcher output

7 PW Output pulse-width programming RC.

8VCCPower source.

■ Recommended Component Values

Rp Program Resistor 1.0 9.1 M½
C

T

Cycle Timer Capacitor 4.7 22.0 µF
CPWPulse Stretcher Capacitor 0.01 0.10 µF
RPWPulse Stretcher Resistor 1 10 M½

V

Load
Switch

PW

OUT

1000

900

800

700

Impedance, W

600

500

400

8.8 8.0 7.0 6.0 5.0 4.0 3.0 2.0 1.0

CC

C

T

1V

V

CC

0V

V

CC

7.1V

T

V

sat

8V

4.6V4.6V

p

1.14ms

BATT. OK

CT Voltage

33S

T

t

1V

6.7V

V

CC

1V

V

CC

T

d

T

pw

V

sat

1ms

510ms

BATT. LOW

2.5V

1.5V

0V

V

CC

4

Program and Standby Currents: I

P

= = Å 1µA Standby Current = 4IP= 4µA (typ.)

9V

9.1m½

V

CC

R

P

Test Pulse Width: Tp= RdCT x ln(VP) Å 242CTÅ 242 x 4.7µF Å 1.14ms

where R

d

is the dynamic cycle timer discharge impedance (440½ typ.)

and V

P

=

[1n(VP) = 0.55 typ.]

Pulse Stretcher: Delay Time: T

D

= = = Å 1ms

where V

d

= Schmitt Trigger Upper Threshold (2.5V typ.)

and I

src

= Typical source current at the PW pin at the nominal low battery sense threshold of 6.7V.

Pulse Width: T

p

= CPWRPWln(VS) Å 0.51 x 0.1µF x 10m½ Å 510ms.

and V

S

= [ln(VS) = 0.51 typ.]

Schmitt Trigger Upper Threshold

Schmitt Trigger Hysteresis

2.5 x 0.1µF
250µA

2.5C

PW

250µA

VdC

PW

I

src

Upper Charge Threshold

Lower Discharge Threshold

Applications Information

Typical Application Circuit

The value of Rpaffects standby current, operating current,
and the test cycle period. The recommended value is
(V+/1µA) where V+ is the fresh battery voltage. Higher
values of Rpare not recommended. Minimum recom­mended value is (V+/10µA) which will increase both the
standby and operating currents by 10X and reduce the test
cycle period by the same factor; the test pulse width will
be unaffected.

The value of Ctaffects both the test cycle period and the
test pulse width. Of critical importance is the selection of a
low leakage type capacitor; if leakage current exceeds the
cycle timer charge current, the timer will not operate.

The pulse stretcher components RPWand CPWshould be
selected such that the delay timer to charge CPWis shorter
than the test pulse width programmed by Ctto guarantee
operation of the Output. The output is an open-collector
transistor which may be used to drive an indicator device
directly or to interface to logic family devices.

The SENSE input typical 8.5k½ input impedance appears
only during the test pulse; otherwise the SENSE input is in
a high impedance state. The effective low battery thresh­old voltage can be modified (increased only) by means of a
voltage divider placed across the load resistor. This tech­nique can also be used to effectively reduce the threshold
tolerance band.

Applications Formulae and Typical Values

CS2516

Cycle Timer Period: Tt=== Å 33sec.,

where V

t

= Upper Charge Threshold - Lower Charge Threshold (7V typ.)

7 x 4.7µF

1µA

7C

T

1µA

VTC

T

I

P

R

p

9.1MW

C

T

4.7mF

+

R

p

SENSE

C

T

CS2516

V

510W

CC

C

0.1mF

R

pw

10MW

pw

V

CC

PW

OUT

COM

Load Switch

220W

+

9V

5

Adjustable Sense Threshold

12V Battery Application with 9V Threshold

Increased Pulse-Load Current Capability

CS2516

R

p

9.1MW

C

T

4.7mF

R

9.1MW

C

4.7mF

R

p

SENSE

CS2516

+

C

T

V

CC

PW

OUT

10MW

OUT

C

0.1mF

R

pw

pw

+

9V

820W

COM

Load Switch

220W

R

L

p

R

p

V

CC

C

SENSE

T

+

CS2516

C

T

PW

OUT

0.1mF

R

10MW

OUT

51W

pw

pw

+

12V

150W

R

9.1MW

C

4.7mF

COM

Load Switch

200W

R

L

220W

+

9V

p

R

p

SENSE

T

+

C

CS-2516

T

COM

V

CC

PW

OUT

Load Switch

OUT

C

pw

0.1mF

R

pw

10MW

1.8kW

Part Number Description

CS2516KN8 8 Lead PDIP
CS2516KD8 8 Lead SOIC
CS2516KDR8 8 Lead SOIC (tape & reel)

6

D

Lead Count Metric English

Max Min Max Min
8L PDIP 10.16 9.02 .400 .355
8L SOIC 5.00 4.80 .197 .189

Thermal Data 8L PDIP 8L SO

RQ

JC

typ 52 45 ûC/W

RQ

JA

typ 100 165 ûC/W

Package Specification

PACKAGE DIMENSIONS IN mm (INCHES)

Ordering Information

PACKAGE THERMAL DATA

Rev. 1/17/95

CS2516

© 1999 Cherry Semiconductor Corporation

Cherry Semiconductor Corporation reserves the
right to make changes to the specifications without
notice. Please contact Cherry Semiconductor
Corporation for the latest available information.

1.27 (.050) BSC

0.51 (.020)

0.33 (.013)

6.20 (.244)

5.80 (.228)

4.00 (.157)

3.80 (.150)

1.57 (.062)

1.37 (.054)

D

0.25 (0.10)

0.10 (.004)

1.75 (.069) MAX

1.27 (.050)

0.40 (.016)

REF: JEDEC MS-012

0.25 (.010)

0.19 (.008)

Surface Mount Narrow Body (D); 150 mil wide

Plastic DIP (N); 300 mil wide

0.39 (.015)
MIN.

2.54 (.100) BSC

1.77 (.070)

1.14 (.045)

D

Some 8 and 16 lead
packages may have
1/2 lead at the end
of the package.
All specs are the same.

.203 (.008)

.356 (.014)

REF: JEDEC MS-001

3.68 (.145)

2.92 (.115)

8.26 (.325)

7.62 (.300)

7.11 (.280)

6.10 (.240)

.356 (.014)

.558 (.022)