UM3085E_15 Datasheet, PDF (1/12 Pages) Union Semiconductor, Inc. – ESD-Protected, Slew-Rate-Limited, Fail-Safe, True RS-485 Transceivers

UM3085E/UM3088E
±15kV ESD-Protected, Slew-Rate-Limited, Fail-Safe,
True RS-485 Transceivers
General Description
UM3085E/UM3088E SOP8/DIP8
The UM3085E, UM3088E are ±15kV ESD-protected, high-speed transceivers for RS-485
communication that contain one driver and one receiver. These devices feature fail-safe circuitry,
which guarantees a logic-high receiver output when the receiver inputs are open, shorted or idle.
This means that the receiver output will be logic high if all transmitters on a terminated bus are
disabled (high impedance). The UM3085E features reduced slew-rate driver that minimizes EMI
and reduces reflections caused by improperly terminated cables, allowing error-free data
transmission up to 500kbps. While partially slew-rate limited UM3088E speeds up to 2.5Mbps.
All devices feature enhanced ESD protection. All transmitter outputs and receiver inputs are
protected to ±15kV using the Human Body Model and IEC61000-4-2, Air-Gap Discharge.
The transceivers typically draw 400μA of supply current when unloaded, or when fully loaded
with the drivers disabled. All devices have a 1/8-unit-load receiver input impedance that allows up
to 256 transceivers on the bus and are intended for half-duplex communications.
Applications
Features
 RS-485 Transceivers
 Level Translators
 Industrial-Control Local Area Networks
 Transceivers for EMI-Sensitive
Applications
 ESD Protection for RS-485 I/O Pins
±15kV—Human Body Model
±15kV—IEC61000-4-2, Air-Gap Discharge
 True Fail-Safe Receiver while Maintaining
EIA/TIA-485 Compatibility
 Enhanced Slew-Rate Limiting Facilitates
Error-Free Data Transmission
 2nA Low-Current Shutdown Mode
 -7V to +12V Common-Mode Input Voltage
Range
 Allows up to 256 Transceivers on the Bus
 Thermal Shutdown
 Current-Limiting for Driver Overload
Protection
Ordering Information
Part Number
Operating
Temperature
UM3085EESA
-40°C to +85°C
UM3085EEPA
-40°C to +85°C
UM3088EESA
-40°C to +85°C
UM3088EEPA
-40°C to +85°C
Marking Code
UM3085EESA
UM3085EEPA
UM3088EESA
UM3088EEPA
Packaging Type
SOP8
DIP8
SOP8
DIP8
Selection Guide
Part
Number
Guaranteed
Date Rate
(Mbps)
UM3085E
0.5
UM3088E
2.5
Low-Power
Shutdown
Yes
Yes
Slew-Rate
Limited
Yes
Yes
Driver/
Receiver
Enable
Yes
Yes
Shutdown
Current
(nA)
2
2
Transceivers
On Bus
256
256
±15kV
ESD
Protection
Yes
Yes
________________________________________________________________________
http://www.union-ic.com Rev.05 Sep.2015
1/12