NSC DS36276MX, DS36276M Datasheet

DS36276
FAILSAFE Multipoint Transceiver

General Description

The DS36276 FAILSAFE Multipoint Transceiver is designed
for use on bi-directional differential busses. It is compatible
with existing TIA/EIA-485 transceivers, however, it offers an
additional feature not supported by standard transceivers.

The FAILSAFE feature guarantees the receiver output to a
known statewhenthe Interface is in the following conditions:
Floating Line, Idle Line (no active drivers), and Line Fault
conditions (open or short). The receiver output is in a HIGH
state for the following conditions: OPEN Inputs, Terminated
Inputs (50Ω), and SHORTED Inputs.

FAILSAFE is a highly desirable feature when the transceiv­ers are used with Asynchronous Controllers such as UARTs.

Features

n FAILSAFE receiver, RO = HIGH for:

— OPEN inputs
— Terminated inputs
— SHORTED inputs

n Compatible with popular interface standards:

— TIA/EIA-485 (RS-485)
— TIA/EIA-422-A (RS-422-A)
— CCITT Recommendation V.11

n Bi-Directional Transceiver

— Designed for multipoint transmission

n Separate driver input, driver enable, receiver enable,

and receiver output for maximum flexibility

n Wide bus common mode range

— (−7V to +12V)

n Pin compatible with: DS75176B, DS96176, DS3695 and

SN75176A and B

n Available in SOIC package

Connection and
Logic Diagram

Truth Tables
Driver

Inputs Outputs

RE

DE DI DO/RI DO /RI

XHH H L
XHL L H
XLX Z Z

Receiver

Inputs Output

RE

DE RI–RI RO
LL ≥0V H
LL≤−500 mV L
HX X Z

Receiver FAILSAFE

Inputs Output

RE

DE RI–RI RO

L L SHORTED H
L L OPEN H
HX X Z

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

DS011383-1

Order Number DS36276M

See NS Package Number M08A

July 1998

DS36276 FAILSAFE Multipoint Transceiver

© 1999 National Semiconductor Corporation DS011383 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

Input Voltage (DE, RE , and DI)

5.5V

Driver Output Voltage/

Receiver Input Voltage −10V to +15V
Receiver Output Voltage (RO) 5.5V
Maximum Package Power Dissipation

@

+25˚C

M Package

(derate 5.8 mW/˚C above
+25˚C) 726 mW

Storage Temperature Range −65˚C to +150˚C

Lead Temperature (Soldering 4
sec.) 260˚C

Max Junction Temperature 150˚C
ESD Rating (HBM, 1.5 kΩ, 100

pF) ≥ 6.0 kV

Recommended Operating
Conditions

Min Max Units

Supply Voltage, V

CC

4.75 5.25 V
Bus Voltage −7 +12 V
Operating Temperature (T

A

)

DS36276 0 +70 ˚C

Electrical Characteristics (Notes 2, 4)

Over recommended Supply Voltage and Operating Temperature ranges, unless otherwise specified.

Symbol Parameter Conditions Min Typ Max Units

DRIVER CHARACTERISTICS

V

OD

Differential Output Voltage IO= 0 mA (No Load) 1.5 4.8 6.0 V

V

oDO

Output Voltage IO= 0 mA (Output to GND) 0 6.0 V

V

oDO

Output Voltage 0 6.0 V

V

T1

Differential Output Voltage
(Termination Load)

RL=54Ω(485) (

Figure 1

) 1.5 2.0 5.0 V

R

L

= 100Ω (422) 2.0 2.3 5.0 V

∆V

T1

Balance of V

T1

|VT1|−|VT1|

RL=54Ω (Note 3) −0.2 0.07 +0.2 V
R

L

= 100Ω −0.2 0.07 +0.2 V

V

OS

Driver Common Mode
Output Voltage

RL=54Ω (

Figure 1

) 0 2.5 3.0 V

R

L

= 100Ω 0 2.3 3.0 V

∆V

OS

Balance of V

OS

|VOS|−|VOS|

RL=54Ω (Note 3) −0.2 0.08 +0.2 V
R

L

= 100Ω −0.2 0.08 +0.2 V

I

OSD

Driver Short-Circuit
Output Current

VO= +12V (

Figure 3

) 134 290 mA

V

O=VCC

140 mA

V

O

= 0V −140 mA

V

O

= −7V −180 −290 mA

RECEIVER CHARACTERISTICS

V

TH

Differential Input High
Threshold Voltage (Note 5)

VO=VOH,IO= −0.4 mA

−7V ≤ V

CM

≤ +12V

−0.18 0 V

V

TL

Differential Input Low
Threshold Voltage (Note 5)

VO=VOL,IO= 8.0 mA

−7V ≤ V

CM

≤ +12V

−0.5 −0.23 V

V

HST

Hysteresis (Note 6) VCM=0V 50 mV

I

IN

Line Input Current
(V

CC

= 4.75V, 5.25V, 0V)

Other Input = 0V
DE=VIH(Note 7)

V

I

= +12V 0.7 1.0 mA

V

I

= −7V −0.5 −0.8 mA

I

OSR

Short Circuit Current VO= 0V RO −5.0 −30 −85 mA

I

OZ

TRI-STATE®Leakage Current VO= 0.4 to 2.4V −20 +20 µA

V

OH

Output High Voltage
(

Figure 12

)

V

ID

= 0V, IOH= −0.4 mA 2.5 3.5 V

V

ID

= OPEN, IOH= −0.4 mA 2.5 3.5 V

V

OL

Output Low Voltage
(

Figure 12

)

V

ID

= −0.5V, IOL= +8 mA 0.25 0.6 V

V

ID

= −0.5V, IOL= +16 mA 0.35 0.7 V

R

IN

Input Resistance 12 19 kΩ

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Electrical Characteristics (Notes 2, 4) (Continued)

Over recommended Supply Voltage and Operating Temperature ranges, unless otherwise specified.

Symbol Parameter Conditions Min Typ Max Units

DEVICE CHARACTERISTICS

V

IH

High Level Input Voltage DE,

RE,
or
DI

2.0 V

CC

V

V

IL

Low Level Input Voltage GND 0.8 V

I

IH

High Level Input Current VIH= 2.4V 20 µA

I

IL

Low Level Input Current VIL= 0.4V −100 µA

V

CL

Input Clamp Voltage ICL= −18 mA −0.75 −1.5 V

I

CC

Output Low Voltage
Supply Current
(No Load)

DE = 3V, RE = 0V, DI = 0V

42 60 mA

I

CCR

DE = 0V, RE = 0V, DI = 0V 28 45 mA

I

CCD

DE = 3V, RE = 3V, DI = 0V 43 60 mA

I

CCX

DE = 0V, RE = 3V, DI = 0V 31 50 mA

Switching Characteristics (Note 4)

Over recommended Supply Voltage and Operating Temperature ranges, unless otherwise specified.

Symbol Parameter Conditions Min Typ Max Units

DRIVER CHARACTERISTICS

t

PLHD

Diff. Prop. Delay Low to High RL=54Ω

C

L

=50pF

C

D

=50pF

(

Figures 4, 5

)

72160 ns

t

PHLD

Diff. Prop. Delay High to Low 7 19 60 ns

t

SKD

Diff. Skew (|t

PLHD–tPHLD

|) 2 10 ns

t

r

Diff. Rise Time 12 50 ns

t

f

Diff. Fall Time 12 50 ns

t

PLH

Prop. Delay Low to High RL=27Ω,CL=15pF

(

Figures 6, 7

)

22 45 ns

t

PHL

Prop. Delay High to Low 22 45 ns

t

PZH

Enable Time Z to High RL= 110Ω

C

L

=50pF

(

Figure 8–Figure 11

)

32 55 ns

t

PZL

Enable Time Z to Low 32 65 ns

t

PHZ

Disable Time High to Z 22 55 ns

t

PLZ

Disable Time Low to Z 16 55 ns

RECEIVER CHARACTERISTICS

t

PLH

Prop. Delay Low to High VID= −1.5V to +1.5V

C

L

=15pF

(

Figures 13, 14

)

15 40 70 ns

t

PHL

Prop. Delay High to Low 15 42 70 ns

t

SK

Skew (|t

PLH–tPHL

|) 2 15 ns

t

PZH

Enable Time Z to High CL=15pF

(

Figures 15, 16

)

15 50 ns

t

PZL

Enable Time Z to Low 17 50 ns

t

PHZ

Disable Time High to Z 24 50 ns

t

PLZ

Disable Time Low to Z 19 50 ns

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

Note 2: Current into devicepins is defined as positive. Current outof device pins is defined as negative.Allvoltagesare referenced to ground unless otherwise speci­fied.

Note 3: ∆ |V

T1

| and ∆ |VOS| are changes in magnitude of VT1and VOS, respectively, that occur when the input changes state.

Note 4: All typicals are given for V

CC

= 5.0V and TA= +25˚C.

Note 5: Threshold parameter limits specified as an algebraic value rather than by magnitude.
Note 6: Hysteresis defined as V

HST=VTH−VTL

.

Note 7: I

IN

includes the receiver input current and driver TRI-STATE leakage current.

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Parameter Measurement Information

DS011383-2

FIGURE 1. Driver VT1and VOSTest Circuit

DS011383-3

FIGURE 2. Driver VOHand VOLTest Circuit

DS011383-4

FIGURE 3. Driver Short Circuit Test Circuit

DS011383-5

FIGURE 4. Driver Differential Propagation Delay and Transition Time Test Circuit

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