Rainbow Electronics MAX3295 User Manual

General Description

The MAX3293/MAX3294/MAX3295 low-power, high­speed transmitters for RS-485/RS-422 communication
operate from a single +3.3V power supply. These
devices contain one differential transmitter. The
MAX3295 transmitter operates at data rates up to
20Mbps, with an output skew of less than 5ns, and a
guaranteed driver propagation delay below 25ns. The
MAX3293 (250kbps) and MAX3294 (2.5Mbps) are
slew-rate limited to minimize EMI and reduce reflections
caused by improperly terminated cables.

The MAX3293/MAX3294/MAX3295 output level is guar­anteed at +1.5V with a standard 54Ω load, compliant
with RS-485 specifications. The transmitter draws 5mA
of supply current when unloaded, and 1µA in low­power shutdown mode (DE = GND).

Hot-swap circuitry eliminates false transitions on the data
cable during circuit initialization or connection to a live
backplane, and short-circuit current limiting and thermal­shutdown circuitry protect the driver against excessive
power dissipation.

The MAX3293/MAX3294/MAX3295 are offered in a
6-pin SOT23 package, and are specified over the
automotive temperature range.

Applications

RS-485/RS-422 Communications

Clock Distribution

Telecom Equipment

Automotive

Security Equipment

Point-of-Sale Equipment

Industrial Control

Features

♦ Space-Saving 6-Pin SOT23 Package

♦ 250kbps/2.5Mbps/20Mbps Data Rates Available

♦ Operate from a Single +3.3V Supply

♦ ESD Protection

±9kV—Human Body Model

♦ Slew-Rate Limited for Errorless Data

Transmission (MAX3293/MAX3294)

♦ 1µA Low-Current Shutdown Mode

♦ -7V to +12V Common-Mode Input Voltage Range

♦ Current Limiting and Thermal Shutdown for

Driver-Overload Protection

♦ Hot-Swap Inputs for Telecom Applications

♦ Automotive Temperature Range (-40°C to +125°C)

MAX3293/MAX3294/MAX3295

20Mbps, +3.3V, SOT23 RS-485/

RS-422 Transmitters

________________________________________________________________ Maxim Integrated Products 1

Selector Guide

Ordering Information

19-2770; Rev 0; 2/03

For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at
1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.

Typical Operating Circuit

Pin Configuration

PART TEMP RANGE

MAX3293AUT-T -40°C to +125°C 6 SOT23-6

MAX3294AUT-T -40°C to +125°C 6 SOT23-6

MAX3295AUT-T -40°C to +125°C 6 SOT23-6

MAXIMUM

PART

MAX3293AUT-T 0.25 Yes ABNI

MAX3294AUT-T 2.5 Yes ABNJ

MAX3295AUT-T 20 No ABNK

DATA RATE

(Mbps)

PIN­PACKAGE

SLEW-RATE

LIMITED

TOP

MARK

TOP VIEW

16Y

DI

V

CC

MAX3293

2

MAX3294
MAX3295

34

SOT23-6

5 GND

ZDE

DI

DE

120Ω

Z

D

MAX3293
MAX3294
MAX3295

Y

R

MAX3280E
MAX3281E
MAX3283E
MAX3284E

RO

MAX3293/MAX3294/MAX3295

20Mbps, +3.3V, SOT23 RS-485/
RS-422 Transmitters

2 _______________________________________________________________________________________

ABSOLUTE MAXIMUM RATINGS

ELECTRICAL CHARACTERISTICS

(VCC= +3.3V ±5%, TA= T

MIN

to T

MAX

, unless otherwise noted. Typical values are at VCC= +3.3V and TA= +25°C.) (Notes 1, 2)

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.

(All voltages referenced to GND, unless otherwise noted.)
Supply Voltage (V

CC

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

DE, DI .......................................................................-0.3V to +6V

Y, Z .........................................................................-7V to +12.5V

Maximum Continuous Power Dissipation (T

A

= +70°C)

6-Pin SOT23 (derate 6.25mW/°C above +70°C).........500mW

Operating Temperature Ranges

MAX32_ _EEUT...............................................-40°C to +85°C

MAX32_ _EAUT ............................................-40°C to +125°C

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

Junction Temperature .....................................................+160°C

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

POWER SUPPLY

Supply Voltage V

Supply Current in Normal
Operation

Supply Current in Shutdown Mode I

DRIVER

Differential Driver Output V

Change in Magnitude of
Differential Output Voltage

Driver Common-Mode Output
Voltage

Change in Magnitude of Common­Mode Voltage

DRIVER LOGIC

Input High Voltage V

Input Low Voltage V

Input Current I

Output Leakage I

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

CC

I

No load, DI = VCC or GND, DE = V

Q

SHDN

∆V

V

∆V

No load, DE = GND 1 10 µA

Figure 1, DE = VCC,

OD

DI = GND or V

Figure 1, R = 27Ω or 50Ω,

OD

DE = V

Figure 1, R = 27Ω or 50Ω,

OC

DE = V

Figure 1, R = 27Ω or 50Ω (Note 3) 0.2 V

OC

DE, DI 2.0 V

IH

DE, DI 0.8 V

IL

DE, DI -2 +2 µA

IN

Y, Z
DE = GND,

O

V

CC

+3.3V

(Note 3)

CC

, DI = VCC or GND

CC

= GND or

3.135 3.300 3.465 V

CC

R = 50Ω (RS-422),

≤ +85°C

T

A

CC

R = 27Ω (RS-485),

≤ +85°C

T

A

VIN = +12V -20 +20

VIN = -7V -20 +20

2.0 V

1.5 V

-1 +3 V

5mA

CC

CC

0.2 V

V

µA

≤ +12V, output high +25

OUT

≤ 1V, output high -25

≤ VCC, output high +250

160 °C

40 °C

TS

TSH

(VCC - 1V) ≤ V

-7V ≤ V

OUT

0 ≤ V

-7V ≤ V

≤ +12V, output low -250

OUT

OUT

Driver Short-Circuit Foldback
Output Current

Driver Short-Circuit
Output Current

Thermal-Shutdown Threshold T

Thermal-Shutdown Hysteresis T

ESD Protection Y, Z Human Body Model ±9 kV

I

OSFD

I

OSD

mA

mA

MAX3293/MAX3294/MAX3295

20Mbps, +3.3V, SOT23 RS-485/

RS-422 Transmitters

_______________________________________________________________________________________ 3

SWITCHING CHARACTERISTICS (MAX3293)

(VCC= +3.3V ±5%, TA= +25°C, unless otherwise noted. Typical values are at VCC= +3.3V.)

SWITCHING CHARACTERISTICS (MAX3294)

(VCC= +3.3V ±5%, TA= +25°C, unless otherwise noted. Typical values are at VCC= +3.3V.)

Driver Propagation Delay

Driver Differential Output Rise
or Fall Time

Driver Output Skew t

Differential Driver Output Skew t

Maximum Data Rate Figures 2, 3; R

Driver Enable to Output High t

Driver Enable to Output Low t

Driver Disable Time from Low t

Driver Disable Time from High t

Device-to-Device Propagation
Delay Matching

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

t

PLH

t

PHL

SKEW

DSKEW

Figures 2, 3; R
C

= 50pF

L

t

R

Figures 2, 3; R
C

t

F

= 50pF

L

Figures 2, 3; R

= | t

t

SKEW

Figures 2, 3; R

Figures 4, 5; S2 closed, RL = 500Ω,

ZH

ZL

LZ

HZ

= 100pF

C

L

Figures 4, 5; S1 closed, RL = 500Ω,

= 100pF

C

L

Figures 4, 5; S1 closed, RL = 500Ω,

= 100pF

C

L

Figures 4, 5; S2 closed, RL = 500Ω,

= 100pF

C

L

PLH

DIFF

DIFF

DIFF

- t

DIFF

DIFF

PHL

= 54Ω,

= 54Ω,

= 54Ω, CL = 50pF,

| (Note 5)

= 54Ω, CL = 50pF -100 +100 ns

= 54Ω, CL = 50pF 250 kbps

Same power supply, maximum temperature
difference between devices = +30°C (Note 5)

400 1300

400 1300

400 1200

400 1200

ns

ns

-400 +400 ns

2000 ns

2000 ns

1000 ns

1000 ns

900 ns

Driver Propagation Delay

Driver Differential Output Rise
or Fall Time

Driver Output Skew t

Differential Driver Output Skew t

Maximum Data Rate Figures 2, 3; R

Driver Enable to Output High t

Driver Enable to Output Low t

Driver Disable Time from Low t

Driver Disable Time from High t

Device-to-Device Propagation
Delay Matching

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

t

PLH

t

PHL

SKEW

DSKEW

Figures 2, 3; R
C

= 50pF

L

t

R

Figures 2, 3; R
C

t

F

= 50pF

L

Figures 2, 3; R

= | t

t

SKEW

Figures 2, 3; R

Figures 4, 5; S2 closed, RL = 500Ω,

ZH

ZL

LZ

HZ

= 100pF

C

L

Figures 4, 5; S1 closed, RL = 500Ω,

= 100pF

C

L

Figures 4, 5; S1 closed, RL = 500Ω,

= 100pF

C

L

Figures 4, 5; S2 closed, RL = 500Ω,

= 100pF

C

L

PLH

DIFF

DIFF

DIFF

- t

DIFF

DIFF

PHL

= 54Ω,

= 54Ω,

= 54Ω, CL = 50pF,

| (Note 5)

= 54Ω, CL = 50pF -6 +6 ns

= 54Ω, CL = 50pF 2.5 Mbps

Same power supply, maximum temperature
difference between devices = +30°C (Note 5)

24 70

24 70

10 70

10 70

ns

ns

-40 +40 ns

400 ns

400 ns

100 ns

100 ns

46 ns

MAX3293/MAX3294/MAX3295

20Mbps, +3.3V, SOT23 RS-485/
RS-422 Transmitters

4 _______________________________________________________________________________________

Note 1: Devices production tested at +25°C. Limits over the operating temperature range are guaranteed by design.
Note 2: 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 3: ∆V

OD

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

Note 4: The maximum current applies to peak current just prior to foldback current limiting.
Note 5: Not production tested. Guaranteed by design.

SWITCHING CHARACTERISTICS (MAX3295)

(VCC= +3.3V ±5%, TA= +25°C, unless otherwise noted. Typical values are at VCC= +3.3V.)

Driver Propagation Delay

Driver Differential Output Rise
or Fall Time

Driver Output Skew t

Differential Driver Output Skew t

Maximum Data Rate

Driver Enable to Output High t

Driver Enable to Output Low t

Driver Disable Time from Low t

Driver Disable Time from High t

Device-to-Device Propagation
Delay Matching

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

t

PLH

t

PHL

SKEW

DSKEW

Figures 2, 3; R

t

R

Figures 2, 3;
R

= 54Ω,

DIFF

= 50pF

C

t

ZH

ZL

LZ

HZ

F

L

Figures 2, 3; R

= | t

t

SKEW

Figures 2, 3; R

Figures 2, 3; R
T

≤ +85°C

A

Figures 2, 3; R

Figures 4, 5; S2 closed, RL = 500Ω,

= 100pF

C

L

Figures 4, 5; S1 closed, RL = 500Ω,

= 100pF

C

L

Figures 4, 5; S1 closed, RL = 500Ω,
C

= 100pF

L

Figures 4, 5; S2 closed, RL = 500Ω,
C

= 100pF

L

Same power supply, maximum temperature
difference between devices = +30°C (Note 5)

= 54Ω, CL = 50pF

DIFF

TA = -40°C to +125°C 18.5

TA < +85°C15

TA = -40°C to +125°C 18.5

T

< +85°C15

A

= 54Ω, CL = 50pF,

DIFF

- t

PLH

|

PHL

= 54Ω, CL = 50pF 5 ns

DIFF

= 54Ω, CL = 50pF,

DIFF

= 54Ω, CL = 50pF 16

DIFF

20

25

25

5ns

400 ns

400 ns

100 ns

100 ns

25 ns

ns

ns

Mbps