NSC DS3696AMX, DS3696AM Datasheet

DS3695A/DS3695AT/DS3696A
Multipoint RS485/RS422 Transceivers

General Description

The DS3695A and DS3696A are high speed differential
TRI-STATE

®

bus/line transceivers designed to meet the re­quirements of EIA standard RS485 with extended common
mode range (+12V to −7V), for multipoint data transmission.
In addition they are compatible with requirements of RS-422.

The driver and receiver outputs feature TRI-STATE capabil­ity. The driver outputs remain in TRI-STATE over the entire
common mode range of +12V to −7V. Bus faults that cause
excessive power dissipation within the device trigger a ther­mal shutdown circuit, which forces the driver outputs into the
high impedance state. The DS3696A provides an output pin
(TS) which reports the thermal shutdown of the device. TS is
an “open collector” pin with an internal 10 kΩ pull-up resistor.
This allows the TS outputs of several devices to be wire
OR-ed.

Both AC and DC specifications are guaranteed over the 0˚C
to 70˚C temperature and 4.75V to 5.25V supply voltage
range.

Features

n Meets EIA standard RS485 for multipoint bus

transmission and is compatible with RS-422

n 10 ns driver propagation delays (typical)
n Single +5V supply
n −7V to +12V bus common mode range permits

±

7V

ground difference between devices on the bus

n Thermal shutdown protection
n High impedance to bus with driver in TRI-STATE or with

power off, over the entire common mode range allows
the unused devices on the bus to be powered down

n Combined impedance of a driver output and receiver

input is less than one RS485 unit load, allowing up to 32
transceivers on the bus

n 70 mV typical receiver hysteresis
n Available in SOIC packaging

Connection and Logic Diagram

TRI-STATE®is a registered trademark of National Semiconductor Corporation.

Molded Package, Small Outline (M)

DS005272-1

Top View

DS005272-2

TS was LF (Line Fault) on previous datasheets, TS goes low upon thermal shutdown.

Top View

Order Number DS3695AM, DS3695ATM or DS3696AM

See NS Package Number M08A

February 1996

DS3695A/DS3695AT/DS3696A Multipoint RS485/RS422 Transceivers

© 1998 National Semiconductor Corporation DS005272 www.national.com

Absolute Maximum Ratings (Note 1)

If Military/Aerospace specified devices are required,
please contact the National Semiconductor Sales Office/
Distributors for availability and specifications.

Supply Voltage, V

CC

7V
Control Input Voltages 7V
Driver Input Voltage 7V
Driver Output Voltages +15V/−10V
Receiver Input Voltages +15V/−10V
Receiver Output Voltage 5.5V
Continuous Power Dissipation 25˚C

M Package 630 mW (Note 4)

Storage Temp. Range −65˚C to +150˚C

Lead Temp. (Soldering 4 seconds) 260˚C

Recommended Operating
Conditions

Min Max Units

Supply Voltage, V

CC

4.75 5.25 V
Bus Voltage −7 +12 V
Operating Free Air Temp. (T

A

)
Commercial (DS3695AM) 0 +70 ˚C
Industrial (DS3695ATM) −40 +85 ˚C
Commercial (DS3696AM) 0 +70 ˚C

Electrical Characteristics (Notes 2, 3)

0˚C ≤ TA≤ 70˚C, 4.75V<V

CC

<

5.25V unless otherwise specified

Symbol Parameter Conditions Min Typ Max Units

V

OD1

Differential Driver Output IO=0

5V

Voltage (Unloaded)

V

OD2

Differential Driver Output R = 50Ω; (RS-422) (Note 5) 2 V
Voltage (with Load) R = 27Ω; (RS-485) 1.5 V

∆V

OD

Change in Magnitude of Driver
Differential Output Voltage For 0.2 V
Complementary Output States

V

OC

Driver Common Mode Output
Voltage

R=27Ω

3.0 V

∆|V

OC

| Change in Magnitude of Driver

Common Mode Output Voltage 0.2 V
For Complementary Output States

V

IH

Input High Voltage 2V

V

IL

Input Low Voltage DI, DE, 0.8 V

V

CL

Input Clamp Voltage RE , RE /DE IIN= −18 mA −1.5 V

I

IL

Input Low Current VIL= 0.4V −200 µA

I

IH

Input High Current VIH= 2.4V 20 µA

I

IN

Input Current DO/RI, DO /RI VCC= 0V or 5.25V VIN= 12V +1.0 mA

RI, RI

DE or RE /DE = 0V VIN= −7V −0.8 mA

V

TH

Differential Input Threshold −7V ≤ VCM≤ +12V

−0.2 +0.2

V

Voltage for Receiver

∆V

TH

Receiver Input Hysteresis VCM=0V 70 mV

V

OH

Receiver Output High Voltage IOH= −400 µA 2.4 V

V

OL

Output Low Voltage RO IOL= 16 mA (Note 5) 0.5 V

TS

IOL= 8 mA 0.45 V

I

OZR

OFF-State (High Impedance) VCC= Max

±

20 µA

Output Current at Receiver 0.4V ≤ V

O

≤ 2.4V

R

IN

Receiver Input Resistance −7V ≤ VCM≤ +12V 12 kΩ

I

CC

Supply Current No Load Driver Outputs Enabled 42 60 mA

(Note 5) Driver Outputs Disabled 27 40 mA

I

OSD

Driver Short-Circuit VO= −7V (Note 5) −250 mA
Output Current V

O

= +12V (Note 5) +250 mA

I

OSR

Receiver Short-Circuit VO= 0V −15 −85 mA
Output Current

Note 1: “Absolute maximum ratings” are those beyond which the safety of the device cannot be guaranteed. They are not meant to imply that the device should be
operated at these limits. The tables of “Electrical Characteristics” provide conditions for actual device operation.

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Electrical Characteristics (Notes 2, 3) (Continued)

Note 2: All currents into device pinsarepositive; all currents out of device pins are negative. All voltages are referenced to device ground unless otherwise specified.
Note 3: All typicals are given for V

CC

= 5V and TA= 25˚C.

Note 4: Derate linearly at 6.5 mW/˚C to 337 mW at 70˚C.
Note 5: All limits for which Note 5 is applied must be derated by 10%for DS3695AT.Other parameters remain the same for this extended temperature range device

(−40˚C ≤ T

A

≤ +85˚C).

Switching Characteristics

0˚C ≤ TA≤ 70˚C, 4.75V<V

CC

<

5.25V unless otherwise specified (Note 3)

Receiver Switching Characteristics

(

Figures 1, 2

and

Figure 3

)

Symbol Conditions Min Typ Max Units

t

PLH

CL=15pF 15 28 42 ns

t

PHL

S1 and S2 15 28 42 ns

|t

PLH–tPHL

| Closed 0 3 ns

t

PLZ

CL= 15 pF, S2 Open 5 29 35 ns

t

PHZ

CL= 15 pF, S1 Open 5 12 16 ns

t

PZL

CL= 15 pF, S2 Open 7 15 28 ns

t

PZH

CL= 15 pF, S1 Open 7 15 20 ns

Driver Switching Characteristics

Symbol Conditions Min Typ Max Units

SINGLE ENDED CHARACTERISTICS (

Figures 4, 5

and

Figure 7

)

t

PLH

R

LDIFF

=60Ω 91522ns

t

PHL

CL1=CL2= 100 pF 9 15 22 ns

t

SKEW|tPLH–tPHL

| 028ns

t

PLZ

CL= 15 pF, S2 Open 7 15 30 ns

t

PHZ

CL= 15 pF, S1 Open 7 15 30 ns

t

PZL

CL= 100 pF, S2 Open 30 35 50 ns

t

PZH

CL= 100 pF, S1 Open 30 35 50 ns

DIFFERENTIAL SWITCHING CHARACTERISTICS (

Figure 7

)

t

r,tf

R

LDIFF

=60Ω

C

L1=CL2

= 100 pF

61018ns

AC Test Circuits and Switching Waveforms

DS005272-6

FIGURE 1. Receiver Propagation Delay Test Circuit

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