Datasheet L9704D, L9704 Datasheet (SGS Thomson Microelectronics)

OCTALSUPPLY CONTACTMONITORINGCIRCUIT

.OPERATING DC SUPPLY VOLTAGE RANGE

5V TO25V

.SUPPLYOVERVOLTAGEPULSEUP TO 40V

.VERY LOW STANDBY QUIESCENT CUR-

RENT0.2mA

.INTERNAL CLAMPINGDIODESAT CONTACT

INPUTS TO V

ANDGND

S

.INPUT PULSECURRENTCAPABILITYUP TO

+ 50mA,– 75mA

.NOMINAL CONTACT CURRENTS OF 10mA

DEFINED BY EXTERNAL CONTACT SERIES
RESISTORSR

IN1-8

.CONTACT STATUS MONITORING BY COM-

PARING THE RESISTANCE AT CONTACT
SENSEINPUTSWITHTHEINTERNALREFER­ENCERESISTORVALUE

.HIGH IMMUNITYDUETORESISTANCECOM-

PARISONWITH HYSTERESIS

L9704

DIP–20

SO–20L

DESCRIP TIO N

TheL9704 is a bipolarmonolithicintegratedcircuit
formonitoringthestatusofup toeightcontactscon­nectedto the powersupply (battery).

BLOCK DI AG RAM

ORDERING NUMBERS: L9704 (DIP–20)

L9704D (SO–20L)

It containseight contactsenseinputsand eight mi­crocomputercompatiblethree-stateoutputs.

March 1992

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L9704

ABSOLUTE MAXIMUM RATINGS

Symbol Parameter Test Conditions Unit

V

V

I

IN DC

I

INP

I

V

P

T

stg,TJ

THERMAL DATA

Symbol Parameter DIP20 SO20 Unit

R

th j-amb

Transient Supply Voltage (t ≤ 1s) +40 V

S

Logic Supply Voltage 7 V

CC

Input DC Current ±40 mA
Input DC Pulse

(test pulse specification: 0 < tP < 2ms, f ≤ 0.2Hz, n = 25000)
Output Current Internally Limited

O

Enable Input Voltage VCC+0.3

EN

50

-75

-0.3

Power Dissipation at T

O

amb

=80°C

DIP20

SO20

875
420

Storage and Junction Temperature Range -55 to 150 °C

Thermal Resistance Junction to Ambient MAX. 80 165 °C/W

mA
mA

V
V

mW
mW

PIN CONNECTION (top view)

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L9704

ELECTRICAL CHARACTERISTICS (5V ≤ VS≤ 25V; -40°C ≤ Tj≤ 125°C; 4.75V ≤ VCC≤ 5.25V unless

otherwise specified; the currents flowing in the arrow direction are assumed positive as marked in the
application circuit diagram, fig. 1).

Symbol Parameter Test Conditions Min. Typ. Max. Unit

V

Enable Input Voltage LOW

ENL

(device activated)

V

V

V
V

I

OUT TS

Enable Input Voltage HIGH 2.4 V

ENH

Enable Input Hysteresis 200 300 800 mV

ENhyst

Enable Input Current 2.4V < VEN<V

I

EN

0V < V

EN

Output Voltage HIGH 0 < I

OUTH

Output Voltage LOW I

OUTL

Output TRISTATE Current 0 < V
Input Voltage (device active) EN = LOW

V

IN

Input Voltage During Clamping

V

IN

(device disabled)

Output Current OUT = HIGH

I

OUT

Output Current OUT = LOW

I

OUT

OUT

= -1mA 0.05 0.2 0.4 V

OUT

OUT<VCC

=1kΩ

R

IN

EN = HIGH

= 30mA

I

IN

= -30mA

I

IN

=0

V

OUT

VOUT = 5.5V

Input Resistor (note 1)

R

IL

LOW Threshold
Input Resistor (note 1)

R

IH

5V < VS< 16V
∆ V

GND

HIGH Threshold

R

Input Resistor

IL

Threshold Ratio (note1)

R

IH

Quiescent Current EN = HIGH (t

I

QC

5V < V

S

-40°C ≤ T

I

QS

SI

2) Input Leakage Current All Inputs Closed V

IN

Quiescent Current EN = LOW 13

I

QC

I

QS

t

Delay Time/Output

do

All Inputs Open

C

≤ 50pF 15

OUT

(EN LOW to output data ready)
Delay Time/Tristate

t

dTS

C

≤ 50pF 10 µs

OUT

(EN HIGH to output TRISTATE)

CC

< 0.8V -5 -1 µA

< 100µA 4.0 VCC-0.1 V

0.4 1.5 2 V

V

+0.3-2VS+1-1VS+2

S

1.1 4.8 KΩ

 ≤ 0.1V

S

6.5 29 KΩ

0.65 0.75 0.85

ENH

≥ 80µs)

0.12 0.16 mA

< 16V

≤ 100°C

j

≤ V

BAT

D1

0.8 V

5 µA

CC

V

0.5 µA

V

-0.3

V

2mA

-20 mA

0.04 mA

0.24 mA
mA

2

mA

µs

+3R

INCIN

Notes :

1. T he input resi stor threshold value is a resist or value from t he IN–pin to battery at w hi ch the cor r es pondi ng output changes
itsstatus(seefig.3)

is the sum of the input currents SIIN=

2: SI

IN

∑

i = 1

8

I

.

IN1

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L9704

APPLI CATI O N CIRCUIT DIAGRAM
Figure 1 :Typicalapplicationdiagramfor the L9704circuit.The currentflowing inthe arrow directionis as-

sumedpositive.The externalcapacitorsC
the correspondingpins.

IN

andC

representthe totalwiring capacitanceat

OUT

FUNCTIO NAL DESCRI PT I O N

TheL9704circuitmonitorsthestatusofthecontacts
connectedtobatteryandthroughtheseriesexternal
resistors R

to the contact sense input pins. The

IN

contacts equivalent circuit is supposed to be as
shown infig. 2.

The L9704 circuitcompares the input current with
the currentthrough the internalreference resistor.
Thedeviceisdesignedtoworkwithanexternalinput
seriesresistorofR

=1kΩ.Withthisinputresistor

IN1-8

the contactcurrent,when thecontactis closedand
the deviceactivated (EN= LOW) is

+∆V

V

BAT

=

I

IN

1KΩ (1)

Forthis calculationthelimitvalueofthe V

BAT

–2V

(satura-

IN

tionvoltageof 2V)was consideredsothatthelowest
limit value ofI

iscalculatedin (1).

IN

Thefunctionof thecircuitcan bedemonstratedwith
the transfer characteristics, showing the output

4/8

status as a functionof the input resistorR
in figure3. Theinputresistorisa sumoftheR
the contactresistanceR

CON

orR

COFF

, shown

I

and

IN

, fortheclosed

contact:

R

I=RIN+RCON

, (2)

and fortheopen contact:

R

I=RIN+RCOFF

. (3)

TheoutputgoesHIGHwhentheinputresistancein­creasesabove6.5kΩ(typicalvalue)andgoesLOW,
when the inputresistancedecreasesbelow 4.8KΩ
(typical value). The limit values of R
LOW andR
withR

=29kΩ forHIGHimpliesthat acontact

I

=100Ω(atIIN=10mA)will berecognized

CON

as ON= LOWand acontactwithR

= 1.1KΩ for

I

=28kΩwill

COFF

be recognized as OFF = HIGH. These limits are
validwithinthesupplyvoltagerange5V≤ V

≤ 16V,

s

the battery voltage potential difference of
∆VBAT≤0.1V

andthevariationofthereverse

BAT

batteryprotectiondiodeD1voltagefrom0.5V to1V.

L9704

Theinternalclampingdiodesatthecontactmonitor­inginputs, togetherwiththe externalcontactseries
resistors R

, allows the device to withstand tran-

IN

sientsatthe contactconnection.Thecontactseries
resistorR

limitsthe input currentat the transient.

IN

The dynamic behaviourof the circuit is definedby
the times t
open, the input capacitor C

do

andt

. Whenthe contact becomes

dTS

must be charged

IN

throughthe resistorR

. In this casethe total delay

IN

timemay alsobeinfluencedbythetimeconstantR
CIN. The delaytime t

, whendisabling thedevice

dTS

isdefinedonlybytheinternalcircuitry. Inbothcases,
anexternaloutputcapacitancelessthan50pFisas­sumed, the internal output capacitances of the
three-statebuffers areless than5pF.

Figure 2 : The ContactSenseInput Connectionwith theContact EquivalentCircuit.

IN

Figure 3 : The OutputVoltageas a Functionof the InputResistanceat the CorrespondingContact Sense

Input.

5/8

L9704

SO20 PACKAGE MECHANICAL DATA

DIM.

MIN. TYP. MAX. MIN. TYP. MAX.

A 2.65 0.104
a1 0.1 0.3 0.004 0.012
a2 2.45 0.096

b 0.35 0.49 0.014 0.019

b1 0.23 0.32 0.009 0.013

C 0.5 0.020
c1 45 (typ.)

D 12.6 13.0 0.496 0.512

E 10 10.65 0.394 0.419

e 1.27 0.050

e3 11.43 0.450

F 7.4 7.6 0.291 0.299
L 0.5 1.27 0.020 0.050

M 0.75 0.030

S 8 (max.)

mm inch

6/8

DIP20 PACKAGE MECHANICAL DATA

L9704

DIM.

MIN. TYP. MAX. MIN. TYP. MAX.

a1 0.254 0.010

B 1.39 1.65 0.055 0.065

b 0.45 0.018

b1 0.25 0.010

D 25.4 1.000

E 8.5 0.335

e 2.54 0.100

e3 22.86 0.900

F 7.1 0.280

I 3.93 0.155
L 3.3 0.130
Z 1.34 0.053

mm inch

7/8

L9704

Information furnished is believed to be accurate and reliable. However, SGS-THOMSON Microelectronics assumes no responsibility for
the consequences of use of such information nor for any infringement of patents or other rights of third parties which may result from its
use. No license is granted by implication or otherwise under any patent or patent rights of SGS-THOMSON Microelectronics. Specifica­tions mentioned in this publication are subject to change without notice. This publication supersedes and replaces all information pre­viously supplied. SGS-THOMSON Microelectronics products are not authorized for use as critical components in life support devices or
systems without express written approval of SGS-THOMSON Microelectronics.

 1994 SGS-THOMSON Microelectronics - All Rights Reserved

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