ISL3178AE Datasheet, PDF (1/14 Pages) Intersil Corporation – ±15kV ESD Protected, 3.3V, Full Fail-Safe, Low Power, High Speed or Slew Rate Limited, RS-485/RS-422 Transceivers

®
Data Sheet
May 6, 2009
ISL3178AE
FN6887.1
±15kV ESD Protected, 3.3V, Full Fail-Safe,
Low Power, High Speed or Slew Rate
Limited, RS-485/RS-422 Transceivers
The Intersil ISL3178AE is ±15kV IEC61000 ESD Protected,
3.3V-powered, single transceivers that meet both the
RS-485 and RS-422 standards for balanced communication.
This device has very low bus currents (+125mA/-100mA),
which presents a true “1/8 unit load” to the RS-485 bus. This
allows up to 256 transceivers on the network without violating
the RS-485 specification’s 32 unit load maximum, and without
using repeaters. For example, in a remote utility meter reading
system, individual meter readings are routed to a concentrator
via an RS-485 network, so the high allowed node count
minimizes the number of repeaters required.
Receiver (Rx) inputs feature a “Full Fail-Safe” design, which
ensures a logic high Rx output if Rx inputs are floating,
shorted, or terminated but undriven.
Hot Plug circuitry ensures that the Tx and Rx outputs remain
in a high impedance state while the power supply stabilizes.
The ISL3178AE is a half duplex version. It multiplexes the
Rx inputs and Tx outputs to allow transceivers with output
disable functions in an 8 Ld package.
Pinout
ISL3178AE
(8 LD SOIC)
TOP VIEW
RO 1
R
RE 2
DE 3
DI 4
D
8 VCC
7 B/Z
6 A/Y
5 GND
Features
• IEC61000 ESD Protection on RS-485 I/O Pins . . . . ±15kV
- Class 3 ESD Level on all Other Pins . . . . . . >7kV HBM
• Full Fail-safe (Open, Short, Terminated/Floating)
Receivers
• Hot Plug - Tx and Rx Outputs Remain Three-state During
Power-up (Only Versions with Output Enable Pins)
• True 1/8 Unit Load Allows up to 256 Devices on the Bus
• Single 3.3V Supply
• High Data Rates . . . . . . . . . . . . . . . . . . . . . . up to 10Mbps
• Low Quiescent Supply Current . . . . . . . . . . .800µA (Max)
- Ultra Low Shutdown Supply Current . . . . . . . . . . .10nA
• -7V to +12V Common Mode Input/Output Voltage Range
• Half Duplex Pinouts
• Three State Rx and Tx Outputs Available
• Current Limiting for Driver Overload Protection
• Pb-Free (RoHS Compliant)
Applications
• Automated Utility Meter Reading Systems
• High Node Count Systems
• Field Bus Networks
• Security Camera Networks
• Building Environmental Control/ Lighting Systems
• Industrial/Process Control Networks
PART
NUMBER
HALF/FUL DATA RATE
L DUPLEX (Mbps)
ISL3178AEM
HALF
10
ISL3178AEMW HALF
10
TABLE 1. SUMMARY OF FEATURES
SLEW-
RATE
LIMITED?
HOT
PLUG?
#
DEVICES
ON BUS
RX/TX
ENABLE?
NO
YES
256
YES
NO
YES
256
YES
QUIESCENT
I_CC (µA)
510
510
LOW POWER PIN
SHUTDOWN? COUNT
YES
8
YES
N/A
1
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
1-888-INTERSIL or 1-888-468-3774 | Intersil (and design) is a registered trademark of Intersil Americas Inc.
Copyright Intersil Americas Inc. 2009. All Rights Reserved
All other trademarks mentioned are the property of their respective owners.