NSC DS36C280TN, DS36C280TMX, DS36C280TM, DS36C280N, DS36C280MX Datasheet

DS36C280
Slew Rate Controlled CMOS EIA-RS-485 Transceiver

General Description

The DS36C280 is a low power differential bus/line trans­ceiver designed to meet the requirements of RS-485 Stan­dard for multipoint data transmission. In addition, it is com­patible with TIA/EIA-422-B.

The slew ratecontrol feature allows the user to set the driver
rise and fall times by using an external resistor. Controlled
edge rates can reduce switching EMI.

The CMOS design offers significant power savings over its
bipolar andALS counterparts without sacrificing ruggedness
against ESD damage. The device is ideal for use in battery
powered or power conscious applications. I

CC

is specified at

500 µA maximum.
The driver and receiver outputs feature TRI-STATE

®

capabil­ity.The driver outputs operate over the entire common mode
range of −7V to +12V. Bus contention or fault situations are
handled by a thermal shutdown circuit, which forces the
driver outputs into the high impedance state.

The receiver incorporates a fail safe circuit which guarantees
a high output state when the inputs are left open (Note 1) .

Features

n 100%RS-485 compliant

— Guaranteed RS-485 device interoperation

n Low power CMOS design: I

CC

500 µA max

n Adjustable slew rate control

— Minimizes EMI affects

n Built-in power up/down glitch-free circuitry

— Permits live transceiver insertion/displacement

n DIP and SOIC packages available
n Industrial temperature range: −40˚C to +85˚C
n On-board thermal shutdown circuitry

— Prevents damage to the device in the event of

excessive power dissipation

n Wide common mode range: −7V to +12V
n Receiver open input fail-safe (Note 1)

n

1

⁄4unit load (DS36C280): ≥128 nodes

n

1

⁄2unit load (DS36C280T): ≥64 nodes

n ESD (human body model): ≥2kV

Connection and Logic Diagram Truth Table

DRIVER SECTION

DE/RE* DI DO/RI DO*/RI*

HHH L
HLL H
LXZ Z

RECEIVER SECTION

DE/RE* RI-RI* RO

L ≥+0.2V H
L ≤−0.2V L
HX Z
L OPEN (Note 1) H

Note 1: Non-terminated, Open Inputs only

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

DS012052-1

Order Number DS36C280TM, DS36C280TN

DS36C280M and DS36C280N

See NS Package Number M08A or N08E

July 1998

DS36C280 Slew Rate Controlled CMOS EIA-RS-485 Transceiver

© 1999 National Semiconductor Corporation DS012052 www.national.com

Absolute Maximum Ratings (Note 2)

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

Supply Voltage (V

CC

) +12V

Input Voltage (DE/RE*, & DI) −0.5V to (V

CC

+0.5V)

Common Mode (V

CM

)

Driver Output/Receiver Input

±

15V

Input Voltage (DO/RI, DO*/RI*)

±

14V

Receiver Output Voltage −0.5V to (V

CC

+0.5V)

Maximum Package Power Dissipation

@

+25˚C
M Package 1190 mV, derate 9.5 mW/˚C above +25˚C
N Package 794 mV, derate 6.0 mW/˚C above +25˚C

Storage Temperature Range −65˚C to +150˚C
Lead Temperature +260˚C

(Soldering 4 sec.)

Recommended Operating
Conditions

Min Typ Max Units

Supply Voltage (V

CC

) +4.75 +5.0 +5.25 V
Bus Voltage −7 +12 V
Operating Free Air Temperature (T

A

)
DS36C280T −40 +25 +85 ˚C
DS36C280 0 +25 +70 ˚C

Electrical Characteristics (Notes 3, 4)

Over Supply Voltage and Operating Temperature ranges, unless otherwise specified

Symbol Parameter Conditions Reference Min Typ Max Units

DIFFERENTIAL DRIVER CHARACTERISTICS

V

OD1

Differential Output Voltage IO= 0 mA (No Load)

(422)
(485)

1.5 5.0 V

V

OD0

Output Voltage IO= 0 mA 0 5.0 V

V

OD0*

Output Voltage (Output to GND) 0 5.0 V

V

OD2

Differential Output Voltage
(Termination Load)

RL=50Ω (422)

Figure 1

2.0 2.8 V

R

L

=27Ω (485) 1.5 2.3 5.0 V

∆V

OD2

Balance of V

OD2

RL=27Ωor 50Ω (Note 5) −0.2 0.1 +0.2 V

|V

OD2−VOD2*

| (422, 485)

V

OD3

Differential Output Voltage
(Full Load)

R1=54Ω,R2=375Ω

Figure 2

1.5 2.0 5.0 V

V

TEST

= −7V to +12V

V

OC

Driver Common Mode
Output Voltage

RL=27Ω (485)

Figure 1

0 3.0 V

R

L

=50Ω (422) 0 3.0 V

∆V

OC

Balance of V

OC

RL=27Ωor (Note 5) −0.2 +0.2 V

|V

OC−VOC*

|R

L

=50Ω (422, 485)

I

OSD

Driver Output Short-Circuit
Current

VO= +12V (485)

Figure 4

200 +250 mA

V

O

= −7V (485) −190 −250 mA

RECEIVER CHARACTERISTICS

V

TH

Differential Input High
Threshold Voltage

VO=VOH,IO= −0.4 mA

(Note 6)

(422, 485)

+0.035 +0.2 V

−7V ≤ V

CM

≤ +12V

V

TL

Differential Input Low
Threshold Voltage

VO=VOL,IO= 0.4 mA −0.2 −0.035 V

−7V ≤ V

CM

≤ +12V

V

HST

Hysteresis VCM=0V 70 mV

R

IN

Input Resistance −7V ≤ VCM≤ +12V DS36C280T 24 68 kΩ

R

IN

Input Resistance −7V ≤ VCM≤ +12V DS36C280 48 68 kΩ

I

IN

Line Input Current
(Note 8)

Other Input = 0V DS36C280 VIN= +12V 0 0.19 0.25 mA
DE=V

IL

,RE*=V

IL

VIN= −7V 0 −0.1 −0.2 mA

V

CC

= 4.75 to 5.25 DS36C280T VIN= +12V 0 0.19 0.5 mA

or 0V V

IN

= −7V 0 −0.1 −0.4 mA

I

ING

Line Input Current
Glitch (Note 8)

Other Input = 0V DS36C280 VIN= +12V 0 0.19 0.25 mA
DE=V

IL

,RE*=V

IL

VIN= −7V 0 −0.1 −0.2 mA

V

CC

= +3.0V DS36C280T VIN= +12V 0 0.19 0.5 mA

or 0V T

A

= 25˚C VIN= −7V 0 −0.1 −0.4 mA

I

B

Input Balance Test RS = 500Ω (422) (Note 10)

±

400 mV

V

OH

High Level Output Voltage IOH= −4 mA, VID= +0.2V RO

Figure 11

3.5 4.6 V

V

OL

Low Level Output Voltage IOL= +4 mA, VID= −0.2V 0.3 0.5 V

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Electrical Characteristics (Notes 3, 4) (Continued)

Over Supply Voltage and Operating Temperature ranges, unless otherwise specified

Symbol Parameter Conditions Reference Min Typ Max Units

RECEIVER CHARACTERISTICS

I

OSR

Short Circuit Current VO= GND RO 7 35 85 mA

I

OZR

TRI-STATE Leakage
Current

VO= 0.4V to 2.4V

±

1µA

DEVICE CHARACTERISTICS

V

IH

High Level Input Voltage

DE/RE*,

DI

2.0 V

CC

V

V

IL

Low Level Input Voltage GND 0.8 V

I

IH

High Level Input Current VIH=V

CC

2µA

I

IL

Low Level Input Current VCC= 5.0V

V

IL

=0V

−2 µA

V

CC

= +3.0V −2 µA

SR=0V SR −1 mA

I

CCR

Power Supply Current
(No Load)

Driver OFF, Receiver ON

V

CC

200 500 µA

I

CCD

Driver ON, Receiver OFF 200 500 µA

Switching Characteristics (Notes 4, 9, 11)

Over Supply Voltage and Operating Temperature ranges, unless otherwise specified

Symbol Parameter Conditions Reference Min Typ Max Units

DRIVER CHARACTERISTICS

t

PHLD

Differential Propagation
Delay High to Low

RL=54Ω,CL= 100 pF

Figures 5, 6

10 399 1000 ns

t

PLHD

Differential Propagation
Delay Low to High

10 400 1000 ns

t

SKD

Differential Skew 0 1 10 ns
|t

PHLD−tPLHD

|

t

r

Rise Time SR = Open 2870 ns

t

f

Fall Time 3070 ns

t

r

Rise Time SR = 100 kΩ 1590 ns

t

f

Fall Time 1640 ns

t

r

Rise Time SR = Short 100 337 1000 ns

t

f

Fall Time 100 348 1000 ns

t

PHZ

Disable Time High to Z CL=15pF

Figures 7, 8

1100 2000 ns

t

PLZ

Disable Time Low to Z

Figures 9, 10

500 800 ns

t

PZH

Enable Time Z to High CL= 100 pF

Figures 7, 8

300 500 ns

t

PZL

Enable Time Z to Low

Figures 9, 10

300 500 ns

RECEIVER CHARACTERISTICS

t

PHL

Propagation Delay
High to Low

CL=15pF

Figures 12, 13

30 210 400 ns

t

PLH

Propagation Delay
Low to High

30 190 400 ns

t

SK

Skew, |t

PHL−tPLH

| 0 20 50 ns

t

PLZ

Output Disable Time CL=15pF

Figures 14, 15, 16

50 150 ns

t

PHZ

55 150 ns

t

PZL

Output Enable Time 40 150 ns

t

PZH

45 150 ns

Note 2: “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 table of “Electrical Characteristics” specifies conditions of device operation.

Note 3: Current into device pins is definedas positive. Current out of device pins is defined as negative. All voltages are referenced to ground except V

OD1

and V

OD2

.

Note 4: All typicals are given for: V

CC

= +5.0V, TA= + 25˚C.

Note 5: Delta |V

OD2

| and Delta |VOC| are changes in magnitude of V

OD2

and VOC, respectively, that occur when input changes state.

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