The ISO1176T is an isolated differential line transceiver with integrated oscillator
outputs that provide the primary voltage for an isolation transformer. The device is ideal for long
transmission lines because the ground loop is broken to allow the device to operate with a much
larger common-mode voltage range.
The symmetrical isolation barrier of each device is tested to provide
4242VPK of isolation per VDE for 60 seconds between the line transceiver and
the logic-level interface.
The galvanically isolated differential bus transceiver is an integrated circuit designed
for bi-directional data communication on multipoint bus-transmission lines. The transceiver
combines a galvanically isolated differential line driver and differential input line receiver. The
driver has an active-high enable with isolated enable-state output on the ISODE pin (pin 10) to
facilitate direction control. The driver differential outputs and the receiver differential inputs
connect internally to form a differential input/output (I/O) bus port that is designed to offer
minimum loading to the bus whenever the driver is disabled or VCC2 =
0.
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 ISO1176T can significantly reduce the risk of
data corruption and damage to expensive control circuits.
The device is characterized for operation over the ambient temperature range of 40°C to
85°C.
- Meets or Exceeds the Requirements of EN 50170
and TIA/EIA-485-A - Signaling Rates up to 40 Mbps
- Easy Isolated Power Design with Integrated
Transformer Driver - Typical Efficiency > 60% (ILOAD = 100 mA) - see
SLUU471 - Differential Output exceeds 2.1 V (54-Ω Load)
- Low Bus Capacitance 10 pF (Maximum)
- Fail-safe Receiver for Bus Open, Short, or Idle
- 50-kV/µs Typical Transient Immunity
- Safety and Regulatory Approvals
- 4242 VPK Basic Insulation per DIN V VDE V
0884-10 and DIN EN 61010-1 - 2500 VRMS Isolation for 1 minute per UL 1577
- CSA Component Acceptance Notice 5A, IEC
60950-1 and IEC 61010-1 Standards
| Type | RS-485 |
| Data rate (max) (MBits) | 40 |
| Operating temperature range (°C) | -40 to 85 |
| Rating | Catalog |
| CMTI (min) (kV/µs) | 25 |
| Isolation rating | Basic, Reinforced |
| Surge isolation voltage (VIOSM) (VPK) | 4000 |
| Withstand isolation voltage (VISO) (Vrms) | 2500 |
| Working isolation voltage (VIOWM) (Vrms) | 400 |
| Transient isolation voltage (VIOTM) (VPK) | 4242 |
| Creepage (min) (mm) | 8 |
| Clearance (min) (mm) | 8 |