ISO35T Datasheet, PDF (1/25 Pages) Texas Instruments – Isolated 3.3V RS-485 Transceiver With Integrated Transformer Driver

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ISO35T
SLLSE26C – NOVEMBER 2010 – REVISED AUGUST 2011
Isolated 3.3V RS-485 Transceiver With Integrated Transformer Driver
Check for Samples: ISO35T
FEATURES
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• 3000V_RMS / 4242V_PK Isolation
• Bus-Pin ESD Protection
– 16 kV HBM Between Bus-Pins and GND2
– 6 kV HBM Between Bus-Pins and GND1
• 1/8 Unit Load – Up to 256 Nodes on a Bus
• Designed for RS-485 and RS-422 Applications
• Signaling Rates up to 1 Mbps
• Thermal Shutdown Protection
• Typical Efficiency > 60% (I_LOAD = 100 mA)
- see SLUU470
• Low Driver Bus Capacitance 16 pF (Typ)
• 50 kV/µs Typical Transient Immunity
• UL 1577, IEC 60747-5-2 (VDE 0884, Rev. 2)
Approvals Pending
• Fail-safe Receiver for Bus Open, Short, Idle
• Logic Inputs are 5-V Tolerant
APPLICATIONS
• Isolated RS-485/RS-422 Interfaces
• Factory Automation
• Motor/Motion Control
• HVAC and Building Automation Networks
• Networked Security Stations
DW PACKAGE
D1 ¹
D2 ²
GND1 3
V_{CC1 4}
R⁵
RE ⁶
DE ⁷
D8
16 ^V_CC2
15 GND2
14 A
13 B
12 Z
11 Y
10 NC
9 GND2
FUNCTION DIAGRAM
1
D1
2 ^OSC
D2
5
R
6
RE
DE ⁷
8
D
14
A
13
B
12
Z
11
Y
DESCRIPTION
The ISO35T is an isolated differential line transceiver with integrated oscillator outputs that provide the primary
voltage for an isolation transformer. The device is a full-duplex differential line transceiver for RS-485 and
RS-422 applications that can easily be configured for half-duplex operation by connecting pin 11 to pin 14, and
pin 12 to pin 13.
These devices are ideal for long transmission lines since the ground loop is broken to allow for a much larger
common-mode voltage range. The symmetrical isolation barrier of the device is tested to provide 4242V_PK of
isolation per VDE for 60s between the bus-line transceiver and the logic-level interface.
Any cabled I/O can be subjected to electrical noise transients from various sources. These noise transients can
cause damage to the transceiver and/or near-by sensitive circuitry if they are of sufficient magnitude and
duration. The ISO35T can significantly reduce the risk of data corruption and damage to expensive control
circuits.
The ISO35T is specified for use from –40°C to 85°C.
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Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of Texas
Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of the Texas
Instruments standard warranty. Production processing does not
necessarily include testing of all parameters.
Copyright © 2010–2011, Texas Instruments Incorporated