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].
For small orders, phone [phone].
________________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 reli-
able communication by reducing intersymbol interfer-
ence (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-cur-
rent 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-unit-
load receiver input impedance allows up to 128 trans-
ceivers 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.