Maxim MAX3292ESD, MAX3292EPD, MAX3292CSD, MAX3292CPD, MAX3291EPD Datasheet

MAX3291/MAX3292

RS-485/RS-422 Transceivers with Preemphasis

for High-Speed, Long-Distance Communication

________________________________________________________________

Maxim Integrated Products

1

19-1405; Rev 1; 4/99

For free samples & the latest literature: http://www.maxim-ic.com, or phone [phone].
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________________General Description

The MAX3291/MAX3292 high-speed RS-485/RS-422
transceivers feature driver preemphasis circuitry, which
extends the distance and increases the data rate of reli­able communication by reducing intersymbol interfer­ence (ISI) caused by long cables. The MAX3291 is
programmable for data rates of 5Mbps to 10Mbps,
while the MAX3292 is programmable for data rates up
to 10Mbps by using a single external resistor.

The MAX3291/MAX3292 are full-duplex devices that
operate from a single +5V supply and offer a low-cur­rent shutdown mode that reduces supply current to
100nA. They feature driver output short-circuit current
limiting and a fail-safe receiver input that guarantees a
logic-high output if the input is open circuit. A 1/4-unit­load receiver input impedance allows up to 128 trans­ceivers on the bus.

________________________Applications

Long-Distance, High-Speed RS-485/RS-422
Communications

Telecommunications
Industrial-Control Local Area Networks

____________________________Features

♦ Preemphasis Increases the Distance and Data

Rate of Reliable RS-485/RS-422 Communication

♦ Data Rate

Optimized for 5Mbps to 10Mbps (MAX3291)
Programmable up to 10Mbps (MAX3292)

♦ 100nA Low-Current Shutdown Mode
♦ Allow Up to 128 Transceivers on the Bus
♦ -7V to +12V Common-Mode Input Voltage Range
♦ Pin-Compatible with ’75180, MAX489, MAX491

MAX3080, MAX3083, MAX3086, MAX1482

2

PEE

(PSET)

12

13

R = Z

O

R = Z

O

R = Z

O

R = Z

O

14

1

1µF

R

PSET

*

C

PSET

*C

PSET

*

7(6)

GND

11

10

9

( ) ARE FOR MAX3292
* MAX3292 ONLY

Z

O

= THE CHARACTERISTIC

IMPEDANCE OF THE CABLE

RO

RE

DE

DI

3
4
5

9

5

13

7(6)

GND

4
3

DI
DE

RE

RO

2

10

11
12

V

CC

(V

CCD

)(V

CCD

)

PEE

(PSET)

14

1

1µF

R

PSET

*

V

CC

MAX3291
MAX3292

MAX3291
MAX3292

A

B

Z

Y

Y
Z

B

A

Typical Operating Circuit and Functional Diagram

PART

MAX3291CSD

MAX3291CPD
MAX3291ESD -40°C to +85°C

0°C to +70°C

0°C to +70°C

TEMP. RANGE PIN-PACKAGE

14 SO
14 Plastic DIP
14 SO

_______________Ordering Information

MAX3291EPD -40°C to +85°C 14 Plastic DIP
MAX3292CSD
MAX3292CPD
MAX3292ESD -40°C to +85°C

0°C to +70°C

0°C to +70°C 14 SO

14 Plastic DIP
14 SO

MAX3292EPD -40°C to +85°C 14 Plastic DIP

Pin Configuration appears at end of data sheet.

MAX3291/MAX3292

RS-485/RS-422 Transceivers with Preemphasis
for High-Speed, Long-Distance Communication

2 _______________________________________________________________________________________

ABSOLUTE MAXIMUM RATINGS

DC ELECTRICAL CHARACTERISTICS

(Typical Operating Circuit, VCC= +5V ±5%, R

PSET

= 0 (MAX3292), VCC= V

CCD

(MAX3292), TA= T

MIN

to T

MAX

, unless otherwise

noted. Typical values are at V

CC

= +5V and TA= +25°C.) (Note 1)

Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional
operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to
absolute maximum rating conditions for extended periods may affect device reliability.

Supply Voltage (VCC, V

CCD

) .................................................+6V

Control Input Voltage (

RE, DE, PEE,

PSET, DI).................................................-0.3V to (V

CC

+ 0.3V)

Driver Output Voltage (Y, Z)................................-7.5V to +12.5V

Receiver Input Voltage (A, B)..............................-7.5V to +12.5V

Receiver Output Voltage (RO)....................-0.3V to (V

CC

+ 0.3V)
Continuous Power Dissipation (T

A

= +70°C)

14-Pin SO (derate 8.7mW/°C above +70°C).................695mW

14-Pin Plastic DIP (derate 10.0mW/°C above +70°C) ..800mW

Operating Temperature Ranges

MAX329_C_ D......................................................0°C to +70°C

MAX329_E_ D...................................................-40°C to +85°C

Storage Temperature Range.............................-65°C to +160°C

Lead Temperature (soldering, 10sec).............................+300°C

R = 27Ω

DE = GND,
VCC= GND or 5.25V

V

PSET

= V

CC

DE, DI, RE

DE, DI, RE, PEE
DE, DI, RE

CONDITIONS

V2.4V

ODP

Differential Driver Output with
Preemphasis

µA

-25

I

O

Output Leakage (Y and Z)

25

µA70 110I

PSET

PSET Input Current (MAX3292)

V

2.4

V

IH

Input High Voltage

V0.8V

IL

Input Low Voltage

µA±2I

IN

Input Current

µA-15 -30 -45I

PEE

PEE Input Current (MAX3291)

UNITSMIN TYP MAXSYMBOLPARAMETER

Figure 1, R = 27Ω (Note 3) V1.65 2.0 2.35DPER

Differential Driver
Preemphasis Ratio

Figure 1, R = 27Ω (Note 4) V0.2

∆VOD,

∆V

ODP

Change in Magnitude of
Differential Output Voltage
(Normal and Preemphasis)

Figure 1, R = 27Ω VV

CC

/ 2 3V

OC

Driver Common-Mode Output
Voltage (Normal and
Preemphasis)

Figure 1, R = 27Ω (Note 5) V0.3∆V

OC

Change in Magnitude of
Common-Mode Voltage
(Normal and Preemphasis)

Figure 1, R = 27Ω mV50∆V

NP

Change in Magnitude of
Common-Mode Output
Voltage (Normal to
Preemphasis)

-7V ≤ V

OUT

≤ +12V (Note 6) mA±30 ±250I

OSD

Driver Short-Circuit Output
Current

VY= VZ= +12V
VY= VZ= -7V

R = 27Ω

Figure 1

No load (Note 2)

V

5.25

V

OD

1.5 5.0

Differential Driver Output

PEE 3.75

DRIVER

MAX3291/MAX3292

RS-485/RS-422 Transceivers with Preemphasis

for High-Speed, Long-Distance Communication

_______________________________________________________________________________________ 3

DC ELECTRICAL CHARACTERISTICS (continued)

(Typical Operating Circuit, VCC= +5V ±5%, R

PSET

= 0 (MAX3292), V

CC

= V

CCD

(MAX3292), TA= T

MIN

to T

MAX

, unless otherwise

noted. Typical values are at V

CC

= +5V and TA= +25°C.) (Note 1)

SWITCHING CHARACTERISTICS

(Typical Operating Circuit, VCC= +5V ±5%, R

PSET

= 0 (MAX3292), VCC= V

CCD

(MAX3292), TA= +25°C, unless otherwise noted.

Typical values are at V

CC

= +5V and TA= +25°C.)

-7V ≤ VCM≤ +12V

RE = V

CC,

DE = GND, VY= VZ= 0 to VCCor

floating

RE = GND, DE = V

CC

0 ≤ VO≤ V

CC

-7V ≤ VCM≤ +12V
0 ≤ VRO≤ V

CC

CONDITIONS

mV-200 200V

TH

Receiver Differential
Threshold Voltage

µA0.1 1I

SHDN

Supply Current in Shutdown
Mode

mA2.0 3.0I

CC + ICCD

No-Load Supply Current

µA0.1 ±1I

OZR

Three-State Output Current at
Receiver

kΩ48R

IN

Receiver Input Resistance

mA±15 ±95I

OSR

Receiver Output Short-Circuit
Current

UNITSMIN TYP MAXSYMBOLPARAMETER

VA= VB= 0 mV35∆V

TH

Receiver Input Hysteresis

IO= -4mA, VA- VB= V

TH

V3.5V

OH

Receiver Output High Voltage

IO= 4mA, VA- VB= -V

TH

V0.4V

OL

Receiver Output Low Voltage

DE = GND,
VCC= GND or 5.25V

µA

-150

IA,

B

250

Input Current (A and B)

VIN= +12V
VIN= -7V

Driver Differential Output
Rise or Fall Time

Figures 3 and 5, R

DIFF

= 54Ω,

CL1= CL2= 50pF

ns

44 65t

DPHL

Driver Propagation Delay

CONDITIONS

t

HL

12

Figures 3 and 5, R

DIFF

= 54Ω,

CL1= CL2= 50pF

ns

t

LH

Differential Driver Output
Skew  t

DPLH

- t

DPHL



Figures 3 and 10, R

DIFF

= 54Ω,

CL1= CL2= 50pF

ns30t

PTND

Preemphasis Voltage Level to
Normal Voltage Level Delay

t

DSKEW

Figures 3 and 5, R

DIFF

= 54Ω,

CL1= CL2= 50pF

38ns

Mbps10f

MAX

Maximum Data Rate

41 65t

DPLH

UNITSMIN TYP MAXSYMBOLPARAMETER

RECEIVER

SUPPLY CURRENT

Driver Preemphasis Interval t

PRE

80 100 120

Figures 3 and 10,
R

DIFF

= 54Ω,

C

L1

= CL2= 50pF

ns

0.75 1 1.25 µs

MAX3292,
R

PSET

= 523kΩ

MAX3291/MAX3292,
R

PSET

= 0

MAX3291/MAX3292

RS-485/RS-422 Transceivers with Preemphasis
for High-Speed, Long-Distance Communication

4 _______________________________________________________________________________________

SWITCHING CHARACTERISTICS (continued)

(Typical Operating Circuit, VCC= +5V ±5%, R

PSET

= 0 (MAX3292), VCC= V

CCD

(MAX3292), TA= +25°C, unless otherwise noted.

Typical values are at V

CC

= +5V and TA= +25°C.)

Note 1: All currents into the device are positive; all currents out of the device are negative. All voltages are referenced to device

ground unless otherwise noted.

Note 2: Guaranteed by design.
Note 3: DPER is defined as (V

ODP

/ VOD).

Note 4: ∆V

ODP

and ∆VOCare the changes in VDDand VOC, respectively, when the DI input changes. This specification reflects

constant operating conditions. When operating conditions shift, the maximum value may be momentarily exceeded.

Note 5: ∆V

ODP

and ∆VOCare the changes in VODand VOC, respectively, when the DI input changes state.

Note 6: Maximum current level applies to peak current just prior to foldback-current limiting; minimum current level applies during

current limiting.

Note 7: Shutdown is enabled by bringing RE high and DE low. If the enable inputs are in this state for less than 50ns, the device is

guaranteed not to enter shutdown. If the enable inputs are in this state for at least 500ns, the device is guaranteed to have
entered shutdown. Time to shutdown for the device (t

SHDN

) is measured by monitoring R0 as in Figure 4.

Figures 2 and 6, S2 closed, RL= 500Ω,
C

L

= 100pF

Figures 2 and 6, RL= 500Ω, CL= 100pF,
S2 closed

CONDITIONS

ns

ns6000 8750t

DZH(SHDN)

Driver Enable from Shutdown
to Output High

UNITSMIN TYP MAXSYMBOLPARAMETER

Figures 4 and 11 (Note 7) ns50 160 500t

SHDN

Time to Shutdown

Figures 2 and 8, RL= 1kΩ, CL= 100pF,
S1 closed

ns34355t

RZL

Receiver Enable to Output
Low

Figures 2 and 8, RL= 1kΩ, CL= 15pF,
S1 closed

ns

Figures 2 and 8, RL= 1kΩ, CL= 100pF,
S2 closed

25 45t

RLZ

Receiver Disable Time from
Low

ns34355t

RZH

Receiver Enable to Output
High

Figures 2 and 8, RL= 1kΩ, CL= 15pF,
S2 closed

ns25 45t

RHZ

Receiver Disable Time from
High

Figures 2 and 6, RL= 500Ω, CL= 100pF,
S1 closed

ns6000 8750t

DZL(SHDN)

Driver Enable from Shutdown
to Output Low

Figures 2 and 8, RL= 1kΩ, CL= 100pF,
S1 closed

ns30 1500t

RZL(SHDN)

Receiver Enable from
Shutdown to Output Low

Figures 2 and 8, RL= 1kΩ, CL= 100pF,
S2 closed

ns850 1500t

RZH(SHDN)

Receiver Enable from
Shutdown to Output High

Figures 7 and 9, CL= 100pF ns3t

RSKEW

Receiver Output Skew
 t

RPLH

- t

RPHL



Driver Enable to Output High t

DZH

72 105

Figures 7 and 9, CL= 50pF, VID= 2V,
VCM= 0

Receiver Propagation Delay

t

RPHL

52 85

ns

49 85t

RPLH

Figures 2 and 6, S2 closed, RL= 500Ω,
C

L

= 15pF

Driver Disable Time from High t

DHZ

71 100 ns

Figures 2 and 6, S1 closed, RL= 500Ω,
C

L

= 15pF

Driver Disable Time from Low t

DLZ

53 100 ns

Figures 2 and 6, S1 closed, RL= 500Ω,
C

L

= 100pF

Driver Enable to Output Low t

DZL

55 105 ns

MAX3291/MAX3292

RS-485/RS-422 Transceivers with Preemphasis

for High-Speed, Long-Distance Communication

_______________________________________________________________________________________

5

TYPICAL PREEMPHASIS WAVEFORM

MAX3291/2-01

100ns/div

V

Y

- V

Z

2V/
div

2500

0

0 1000

PREEMPHASIS INTERVAL vs. R

PSET

(C

PSET

= 0.1µF)

250

500

2250

MAX3291/2-02

R

PSET

(kΩ)

PREEMPHASIS INTERVAL (ns)

200100 300 400 600500

800

700 900

2000
1750

750

1500
1250
1000

NOTE A

0

400

200

800

NOTE A

600

1000

1200

0 1000500 1500 2000

R

PRE

AND t

PRE

vs. t

BAUD

MAX3291/92 toc 03

t

BAUD

(ns)

R

PRE

(kΩ)

0

1.0

0.5

2.0

1.5

2.5

3.0

4.0

3.5

4.5

10 30 40 5020 60 70 80 90

100

DRIVER DIFFERENTIAL

OUTPUT VOLTAGE vs. R

DIFF

MAX3291/2-04

R

DIFF

(Ω)

DRIVER DIFFERENTIAL OUTPUT VOLTAGE (V)

STRONG

NORMAL

30.0

35.0

32.5

40.0

37.5

42.5

47.5

45.0

50.0

-40 0 20-20 40 60 80

100

DRIVER PROPAGATION DELAY

vs. TEMPERATURE

MAX3291/2-07

TEMPERATURE (°C)

PROPAGATION DELAY (ns)

C

L1

= C

L2

= 50pF

2.00

2.50

2.25

3.00

2.75

3.25

3.50

4.00

3.75

4.25

-40 0 20-20 40 60 80

100

DRIVER DIFFERENTIAL

OUTPUT VOLTAGE vs. TEMPERATURE

MAX3291/2-05

TEMPERATURE (°C)

DIFFERENTIAL OUTPUT VOLTAGE (V)

STRONG (V

ODP

)

R

DIFF

= 54Ω

NORMAL (VOD)

40.0

45.0

42.5

50.0

47.5

52.5

57.5

55.0

60.0

-40 0 20-20 40 60 80

100

RECEIVER PROPAGATION DELAY

vs. TEMPERATURE

MAX3291/2-06

TEMPERATURE (°C)

PROPAGATION DELAY (ns)

CL = 50pF

RECEIVER PROPAGATION DELAY

MAX3291/2-08

20ns/div

V

A

- V

B

RO

2.5V/
div

5V/
div

__________________________________________Typical Operating Characteristics

(VCC= +5V, TA= +25°C, unless otherwise noted.)

Note A: Dotted line represents region in which preemphasis may not work in systems with excessive power-supply noise. See

Preemphasis at Low Data Rates

.