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1

SP3493/3494DS/03           SP3493/3494 +3.3V Low Power Slew-Rate Limited RS-485/RS-422 Transceivers         © Copyright 2000 Sipex Corporation

Operates From A Single +3.3V Supply

Interoperable With +5V Logic

+200mV Receiver Input Sensitivity

Slew-Rate Limited For Errorless Data

Transmission to 250Kbps

-7V to +12V Common-Mode Input

Voltage Range

Devices Allow Up To 32 Transceivers

On The Serial Bus

Driver/Receiver Enable Lines (SP3494)

2nA Low-Power Shutdown Mode (SP3494)

Compatible With The MAX3488, LTC490

and 75179 Industry Standard Pinouts

(SP3493)

Compatible With The MAX3486 and 75176

Industry Standard Pinouts (SP3494)

+3.3V Low Power Slew Rate Limited

RS-485/RS-422 Transceivers

SP3493/SP3494

DESCRIPTION

The  SP3493  and the 3494 devices are +3.3V, slew-rate limited transceivers that meet the

specifications of the RS-485 and RS-422 serial protocols. The SP3493 and the 3494 devices

are pin-to-pin compatible with the Sipex SP3490 and the SP3481 devices, respectively, as well

as other popular industry standards. The devices feature Sipex's BiCMOS process, allowing

low power operation without sacrificing performance. The slew-rate limited drivers minimize

EMI and reduce reflections caused by improperly terminated cables allowing

error-free data transmission. The SP3493 is a full-duplex slew-rate limited transceiver that will

deliver a data transmission rate up to 250kbps. The SP3494 is a half-duplex slew-rate limited

transceiver that will deliver a data transmission rate up to 2.5Mbps. The SP3494 is equipped

with a low-power shutdown mode and driver/receiver high-Z enable lines.

1

2

3

4

5

6

7

8

R

D

Vcc

GND

R

D

A

B

Z

Y

RO   1

RE   2

DE   3

DI   4

8    V

CC

7    B

6    A

5    GND

D

R

SP3493

SP3494

®

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SP3493/3494DS/03           SP3493/3494 +3.3V Low Power Slew-Rate Limited RS-485/RS-422 Transceivers         © Copyright 2000 Sipex Corporation

SPECIFICATIONS

T

AMB

 = T

MIN 

to T

MAX  

and V

CC

 = 3.3V 

±

 5% unless otherwise noted.

PARAMETERS

MIN.

TYP.

MAX.

UNITS

CONDITIONS

SP3493 DRIVER

DC Characteristics

Differential Output Voltage

GND

V

CC

Volts

Unloaded; R = 

 

Figure 1

Differential Output Voltage

2

V

CC

Volts

With Load; R = 50

; (RS-422);

Figure 1

Differential Output Voltage

1.5

V

CC

Volts

With Load; R = 27

; (RS-485); 

 Figure 1

Change in Magnitude of Driver

Differential Output Voltage for

Complimentary States

0.2

Volts

R = 27

 or R = 50

Figure 1

Driver Common-Mode

Output Voltage

3

Volts

R = 27

 or R = 50

Figure 1

Input High Voltage

2.0

Volts

Input Low Voltage

0.8

Volts

Input Current

+10

µ

A

Driver Short-Circuit Current

   V

OUT

 = HIGH

+250

mA

-7V < V

O

 < +12V

   V

OUT

 = LOW

+250

mA

-7V < V

O

 < +12V

SP3493 DRIVER

AC Characteristics

Maximum Data Rate

250

kbps

Driver Input to Output, t

PLH

400

900

1500

ns

Figures 2 and 8

Driver Input to Output, t

PHL

400

900

1500

ns

Figures 2 and 8

Differential Driver Skew

10

ns

 t

PHL

(Y) - t

PLH

(Y) , t

PHL

(Z) - t

PLH

(Z) ,

Figures 2 and 8

Figures 2 and 8

Driver Rise or Fall Time

10

30

ns

From 10% to 90%; 

Figures 3 and 9

SP3493 RECEIVER

DC Characteristics

Differential Input Threshold

0.2

+0.2

Volts

-7V < V

CM 

< 12V

Input Hysteresis

25

mV

V

CM

 = 0V

Output Voltage High

 V

CC

-0.4

Volts

I

O

 = -1.5mA, V

ID

 = +200mV

Output Voltage Low

0.4

Volts

I

O

 = +2.5mA,  V

ID

 = -200mV

Input Resistance

12

15

k

-7V < V

CM 

< 12V

Input Current (A, B); V

IN

 = 12V

1.0

mA

V

IN

 = 12V

Input Current (A, B); V

IN

 = -7V

-0.8

mA

V

IN

 = -7V

Short-Circuit Current

60

mA

0V < V

O

 < V

CC

ABSOLUTE MAXIMUM RATINGS

These are stress ratings only and functional operation of the device at

these ratings or any other above those indicated in the operation sections

of the specifications below is not implied. Exposure to absolute maximum

rating conditions for extended periods of time may affect reliability.

V

CC

............................................................................................................................+7V

Input Voltages

Drivers................................................-0.5V to (V

CC

+0.5V)

Receivers..................................................................

±

14V

Output Voltages

Drivers......................................................................

±

14V

Receivers...........................................-0.5V to (V

CC

+0.5V)

Storage Temperature....................................................-65˚C to +150˚

Power Dissipation per Package

8-pin PDIP (derate11.8mW/

o

C above +70

o

C)...........................1000mW

8-pin NSOIC (derate 6.90mW/

o

C above +70

o

C).........................600mW

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SP3493/3494DS/03           SP3493/3494 +3.3V Low Power Slew-Rate Limited RS-485/RS-422 Transceivers         © Copyright 2000 Sipex Corporation

SPECIFICATIONS (continued)

T

AMB 

= T

MIN 

to T

MAX  

and V

CC

 = 3.3V 

±

 5% unless otherwise noted.

PARAMETERS

MIN.

TYP.

MAX.

UNITS

CONDITIONS

SP3493 RECEIVER

AC Characteristics

Maximum Data Rate

250

kbps

Receiver Input to Output, t

PLH

35

70

120

ns

Figures 6 and 11

Receiver Input to Output, t

PHL

35

70

120

ns

Figures 6 and 11

Differential Receiver Skew

10

ns

Figures 6 and 11

SP3493 POWER REQUIREMENTS

Supply Current

1000

2000

µ

A

D = 0 or V

CC

SP3494 DRIVER

DC Characteristics

Differential Output Voltage

GND

V

CC

Volts

Unloaded; R = 

Figure 1

Differential Output Voltage

2

V

CC

Volts

with load; R = 50

; (RS-422); 

Figure 1

Differential Output Voltage

1.5

V

CC

Volts

with load; R = 27

; (RS-485);

 Figure 1

Change in Magnitude of Driver

Differential Output Voltage for

Complimentary States

0.2

Volts

R = 27

 or R = 50

Figure 1

Driver Common-Mode

Output Voltage

3

Volts

R = 27

 or R = 50

Figure 1

Input High Voltage

2.0

Volts

Applies to DE, DI, RE

Input Low Voltage

0.8

Volts

Applies to DE, DI, RE

Input Current

+10

µ

A

Applies to DE, DI, RE

Driver Short-Circuit Current

   V

OUT

 = HIGH

+250

mA

-7V < V

O

 < +12V

   V

OUT

 = LOW

+250

mA

-7V < V

O

 < +12V

SP3494 DRIVER

AC Characteristics

Maximum Data Rate

2.5

Mbps

RE = V

CC

, DE = V

CC

Driver Input to Output, t

PLH

20

45

75

ns

Figures 2 and 8

Driver Input to Output, t

PHL

20

45

75

ns

Figures 2 and 8

Differential Driver Skew

10

ns

t

DO1

 - t

DO2 

Figures 2 and 9

Driver Rise or Fall Time

30

70

ns

From 10% to 90%, 

Figures 3 and

 9

Driver Enable to Output High

52

120

ns

Figures 4 and 10

Driver Enable to Output Low

60

120

ns

Figures 5 and 10

Driver Disable Time from Low

40

120

ns

Figures 5 and 10

Driver Disable Time from High

60

120

ns

Figures 4 and 10

SP3494 RECEIVER

DC Characteristics

Differential Input Threshold

-0.2

         +0.2

Volts

-7V < V

CM 

< +12V

Input Hysteresis

20

mV

V

CM

 = 0V

Output Voltage High

   V

CC

-0.4

Volts

V

ID

 = +200mV, -1.5mA

Output Voltage Low

           0.4

Volts

V

ID

 = -200mV, 2.5mA

Three-State (High Impedance)

Output Current

          +1

µ

A

0V < V

< V

CC

; RE = V

CC

Input Resistance

12

15

k

-7V < V

CM 

< +12V

Input Current (A, B); V

IN

 = 12V

         1.0

mA

DE = 0V, V

CC

 = 0V or 3.6V, V

IN

 = 12V

Input Current (A, B); V

IN

 = -7V

         -0.8

mA

DE = 0V, V

CC

 = 0V or 3.6V, V

IN

 = -7V

Short-Circuit Current

7

         60

mA

0V < V

CM

 < V

CC

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SP3493/3494DS/03           SP3493/3494 +3.3V Low Power Slew-Rate Limited RS-485/RS-422 Transceivers         © Copyright 2000 Sipex Corporation

SPECIFICATIONS (continued)

T

AMB

 = T

MIN 

to T

MAX  

and V

CC

 = +3.3V 

±

 5% unless otherwise noted.

PARAMETERS

MIN.

TYP.

MAX.

UNITS

CONDITIONS

SP3494 RECEIVER

AC Characteristics

Maximum Data Rate

2.5

Mbps

RE = 0V, DE = 0V

Receiver Input to Output, t

PLH

40

70

100

ns

Figures 6 and 11

Receiver Input to Output, t

PHL

40

70

100

ns

Figures 6 and 11

Differential Receiver Skew

10

ns

t

RSKEW 

=

 

 t

RPHL 

-

 

t

RPLH 

Figures 6 and 11

Receiver Enable to

Output Low

35

60

ns

Figures 7 and 12; S

1

 closed, S

2

 open

Receiver Enable to

Output High

35

60

ns

Figures 7 and 12; S

2

 closed, S

1

 open

Receiver Disable from Low

35

60

ns

Figures 7 and 12; S

1

 closed, S

2

 open

Receiver Disable from High

35

60

ns

Figures 7 and 12; S

2

 closed, S

1

 open

SP3494 SHUTDOWN TIMING

Time to Shutdown

50

75

200

ns

RE = 3.3V, DE = 0V

Driver Enable from Shutdown

to Output High

65

150

ns

Figures 4 and 10

Driver Enable from Shutdown

to Output Low

65

150

ns

Figures 5 and 10

Receiver Enable from

Shutdown to Output High

50

200

ns

Figures 7 and 12; S

closed, S

1

 open

Receiver Enable from

Shutdown to Output Low

50

200

ns

Figures 7 and 12; S

1

 closed, S

2

 open

SP3494 POWER REQUIREMENTS

Supply Current

   No Load

1000

2000

µ

A

RE, DI = 0V or V

CC

; DE = V

CC

800

1500

µ

A

RE = 0V, DI = 0V or V

CC

; DE = 0V

   Shutdown Mode

10

µ

A

DE = 0V, RE=V

CC

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SP3493/3494DS/03           SP3493/3494 +3.3V Low Power Slew-Rate Limited RS-485/RS-422 Transceivers         © Copyright 2000 Sipex Corporation

PIN FUNCTION - SP3493

Pin 1 - V

CC

 - Positive supply +3.00 < V

CC

 < +3.60

Pin 2 - R - Receiver output.

Pin 3 - D - Driver input.

Pin 4 - GND - Ground connection.

Pin 5 - Y - Non-inverting driver output.

Pin 6 - Z - Inverting driver output.

Pin 7 - B - Inverting receiver input.

Pin 8 - A - Non-inverting receiver input.

1

2

3

4

5

6

7

8

R

D

Vcc

GND

R

D

A

B

Z

Y

PIN FUNCTION - SP3494

Pin 1 – RO – Receiver Output.

Pin 2 – RE – Receiver Output Enable Active LOW.

Pin 3 – DE – Driver Output Enable Active HIGH.

Pin 4 – DI – Driver Input.

Pin 5 – GND – Ground Connection.

Pin 6 – A – Driver Output/Receiver Input

Non-inverting.

Pin 7 – B – Driver Output/Receiver Input Inverting.

Pin 8 – Vcc – Positive Supply +3.00V < V

CC

 < +3.60V

SP3494

Pinout

RO   1

RE   2

DE   3

DI   4

8    V

CC

7    B

6    A

5    GND

D

R

SP3493

Pinout

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SP3493/3494DS/03           SP3493/3494 +3.3V Low Power Slew-Rate Limited RS-485/RS-422 Transceivers         © Copyright 2000 Sipex Corporation

DESCRIPTION

The SP3493/3494 are +3.3V transceivers that

meet the electrical specifications of the

RS-485 and RS-422 serial protocols. The

SP3493/3494 feature Sipex's BiCMOS process

allowing low power operation without

sacrificing performance.

The  SP3493  device is a +3.3V full-duplex

transceiver that is pin-to-pin compatible with

the Sipex SP3490 and SP490 devices as well as

popular industry standards such as the

MAX3488, the LTC490, and the 75179.  The

SP3493 has a slew-rate limited driver with a

data transmission rate of 250kbps.

The  SP3494  device is a +3.3V half-duplex

transceiver that is pin-to-pin compatible with

the Sipex SP3481 and SP481 devices as well as

popular industry standards such as the MAX3486

and the 75176. The SP3494 has a slew-rate

limited driver with a data transmission rate of

2.5Mbps.

Drivers

The SP3493/3494devices both have differential

outputs. The typical voltage output swing with

no load will bo 0V to V

CC

. With worst case

loading of 54

 across the differential outputs,

the driver can maintain greater than 1.5V voltage

levels.

The  SP3494  device has an enable control line

which is active HIGH. A logic HIGH on DE (pin

3) will enable the differential driver outputs.

A logic LOW on DE (pin 3) will force the driver

outputs at high impedance (high-Z).  The SP3493

device does not have a driver enable.

The slew-rate limited SP3493/SP3494 drivers

will operate up to 250kbps and 2.5Mbps,

respectively. In addition to adhering to the

250mA I

SC

 maximum limit on the driver output,

the driver output short-circuit protection will

allow the devices to withstand an infinite short

circuit over the -7.0V to +12V common mode

range without damage.

Receivers

The receivers have differential inputs with an

input sensitivity as low +200mV. Input

impedance of the receivers is typically 15k

(12k

 minimum).  A wide common mode range

of -7V to +12V allows for large ground potential

differences between systems.

Both the SP3493/SP3494 receivers are

equipped with fail-safe which guarantees that

the receiver outputs will be in a high state

when the input is left unconnected.

The  SP3494  receiver has a high impedance

(high-Z) enable control pin.  A logic LOW on

RE (pin 2) will enable the receiver; a logic

HIGH on RE (pin 2) will disable the receiver.

The SP3494 is equipped with a shutdown mode.

To enable the shutdown state, both the driver

and receiver must be disabled simultaneously.

A logic LOW on DE (pin 3) and a logic HIGH

on RE (pin 2) will put the SP3494 into shutdown.

In shutdown, the supply current will drop to 2nA

typical, 1

µ

A maximum.

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SP3493/3494DS/03           SP3493/3494 +3.3V Low Power Slew-Rate Limited RS-485/RS-422 Transceivers         © Copyright 2000 Sipex Corporation

INPUTS

OUTPUTS

LINE

RE

DE

DI CONDITION

B

A

X

1

1

No Fault

0

1

X

1

0

No Fault

1

0

X

0

X

X

Z

Z

INPUTS

OUTPUTS

RE

DE

A - B

R

0

0

 +0.2V

1

0

0

 -0.2V

0

0

0

Inputs Open

1

1

0

X

Z

Table 1. Transmit Function Truth Table

Table 2. Receive Function Truth Table

Figure 1. Driver DC Test Load Circuit

Figure 7. Receiver Enable and Disable Timing Circuit

R

R

V

OC

D

V

CC

V

OD

GENERATOR

   (NOTE 1)

50

V

CC

S1

V

DM

R

L

 = 27

OUT

C

L

 = 15pF

 (NOTE 2)

V

OM

 =                        1.5V

V

OH

 + V

OL

       2

D

GENERATOR

   (NOTE 1)

50

S1

R

L

 = 110

OUT

C

L

 = 50pF

 (NOTE 2)

V

OM

 =                        1.5V

V

OH

 + V

OL

       2

D

GENERATOR

   (NOTE 1)

50

S1

R

L

 = 110

OUT

C

L

 = 50pF

 (NOTE 2)

D

0V OR 3V

V

CC

GENERATOR

   (NOTE 1)

50

1.5V

0V

V

ID

R

OUT

C

L

 = 15pF

 (NOTE 2)

V

OM

 = V

CC

            2

1.5V

-1.5V

S3

V

ID

GENERATOR

   (NOTE 1)

50

C

= 15pF

(NOTE 2)

R

1k

S1

S2

V

CC

Figure 5. Driver Enable and Disable Timing Circuit,

Output LOW

GENERATOR

   (NOTE 1)

50

C

L

OUT

D

V

CC

R

L

 =

60

C

= 15pF (NOTE 2)

Figure 3. Driver Differential Output Delay and

Transition Time Circuit

Figure 2. Driver Propagation Delay Test Circuit

Figure 6. Receiver Propagation Delay Test Circuit

Figure 4. Driver Enable and Disable Timing Circuit,

output HiGH

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SP3493/3494DS/03           SP3493/3494 +3.3V Low Power Slew-Rate Limited RS-485/RS-422 Transceivers         © Copyright 2000 Sipex Corporation

Figure 8. Driver Propagation Delay Waveforms

Figure 12. Receiver Enable and Disable Waveforms

Figure 11. Receiver Propagation Delay Waveforms

Figure 10. Driver Enable and Disable Timing Waveforms

0V

V

OH

t

PLH

t

PHL

V

OM

t

PHL

t

PLH

3V

V

OL

V

OH

1.5V

1.5V

INPUT

Y OUTPUT

V

OM

Z OUTPUT

V

OL

V

OM

V

OM

V

OM

 = V

OH

 + V

OL

2

 1.5V

0V

V

OH

t

PZH

0.25V

t

PHZ

V

OM

t

PZL

t

PLZ

3V

V

OL

V

CC

1.5V

1.5V

DE

OUTPUT

HIGH

V

OM

0.25V

0V

OUTPUT

LOW

V

OM

 = V

OH

 + V

OL

2

 1.5V

3V

0V

V

CC

t

RPLH

1.5V

t

RPHL

V

OM

V

OM

0V

1.5V

INPUT

OUTPUT

V

OM

 = V

CC

2

3V

0V

t

PRHZ

1.5V

t

PRZH

t

PRSH

1.5V

1.5V

10%

0V

V

OH

RE

OUTPUT

S1 is open

S2 is closed

S3 = 1.5V

3V

0V

t

PRLZ

1.5V

t

PRZL

t

PRSL

1.5V

1.5V

10%

V

CC

RE

OUTPUT

S1 is closed

S2 is open

S3 = -1.5V

V

OL

NOTE 1: The input pulse is supplied by a generator with the following characteristics:

PRR=250KHz, 50% duty cycle, t

r

 < 6.0ns, Z

0

=50

.

NOTE 2: C

L

 includes probe and stray capacitance.

IN

1.5V

t

DO1

1.5V

t

DO2

3V

0V

OUT

50%

50%

10%

10%

90%

90%

t

TD

t

TD

2.0V

-2.0V

Figure 9. Driver Differential Output Delay and

Transition Time Waveforms

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SP3493/3494DS/03           SP3493/3494 +3.3V Low Power Slew-Rate Limited RS-485/RS-422 Transceivers         © Copyright 2000 Sipex Corporation

D

ALTERNATE

END PINS

(BOTH ENDS)

D1 = 0.005" min.

(0.127 min.)

E

PACKAGE: PLASTIC

DUAL–IN–LINE

(NARROW)

DIMENSIONS (Inches)

Minimum/Maximum

(mm)

A = 0.210" max.

(5.334 max).

E1

C

Ø

L

A2

A1 = 0.015" min.

(0.381min.)

B

B1

e = 0.100 BSC

(2.540 BSC)

e

A

 = 0.300 BSC

(7.620 BSC)

A2

B

B1

C

D

E

E1

L

Ø

0.115/0.195

(2.921/4.953)

0.014/0.022

(0.356/0.559)

0.045/0.070

(1.143/1.778)

0.008/0.014

(0.203/0.356)

0.355/0.400

(9.017/10.160)

0.300/0.325

(7.620/8.255)

0.240/0.280

(6.096/7.112)

0.115/0.150

(2.921/3.810)

0°/ 15°

(0°/15°)

8–PIN

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SP3493/3494DS/03           SP3493/3494 +3.3V Low Power Slew-Rate Limited RS-485/RS-422 Transceivers         © Copyright 2000 Sipex Corporation

D

E

H

PACKAGE: PLASTIC

SMALL OUTLINE (SOIC)

(NARROW)

DIMENSIONS (Inches)

Minimum/Maximum

(mm)

8–PIN

A

A1

Ø

L

B

e

h x 45°

A

A1

B

D

E

e

H

h

L

Ø

0.053/0.069

(1.346/1.748)

0.004/0.010

(0.102/0.249

0.014/0.019

(0.35/0.49)

0.189/0.197

(4.80/5.00)

0.150/0.157

(3.802/3.988)

0.050 BSC

(1.270 BSC)

0.228/0.244

(5.801/6.198)

0.010/0.020

(0.254/0.498)

0.016/0.050

(0.406/1.270)

0°/8°

(0°/8°)

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SP3493/3494DS/03           SP3493/3494 +3.3V Low Power Slew-Rate Limited RS-485/RS-422 Transceivers         © Copyright 2000 Sipex Corporation

ORDERING INFORMATION

Model

Temperature Range

Package

SP3493CN

0˚C to +70˚C

8-pin Narrow SOIC

SP3493CP

0˚C to +70˚C

8-pin Plastic DIP

SP3493EN

.-40˚C to +85˚C

8-pin Narrow SOIC

SP3493EP

-40˚C to +85˚C

8-pin Plastic DIP

SP3494CN

0˚C to +70˚C

8-pin Narrow SOIC

SP3494CP

0˚C to +70˚C

8-pin Plastic DIP

SP3494EN

-40˚C to +85˚C

8-pin Narrow SOIC

SP3494EP

-40˚C to +85˚C

8-pin Plastic DIP

Please consult the factory for pricing and availability on a Tape-On-Reel option.

Corporation

SIGNAL PROCESSING EXCELLENCE

Sipex Corporation reserves the right to make changes to any products described herein. Sipex does not assume any liability arising out of the

application or use of any product or circuit described hereing; neither does it convey any license under its patent rights nor the rights of others.

Sipex Corporation

Headquarters and

Sales Office

22 Linnell Circle

Billerica, MA  01821

TEL: (978) 667-8700

FAX: (978) 670-9001

e-mail: sales@sipex.com

Sales Office

233 South Hillview Drive

Milpitas, CA 95035

TEL: (408) 934-7500

FAX: (408) 935-7600