2.5 kVrms Isolated Bidirectional Clock, Bidirectional I2C Isolators - ISO1540


2.5 kVrms Isolated Bidirectional Clock, Bidirectional I2C Isolators



The ISO1540 and ISO1541 devices are low-power, bidirectional isolators that are compatible with I2C interfaces. These devices have their logic input and output buffers separated by TI’s Capacitive Isolation technology using a silicon dioxide (SiO2) barrier. When used with isolated power supplies, these devices block high voltages, isolate grounds, and prevent noise currents from entering the local ground and interfering with or damaging sensitive circuitry.

This isolation technology provides for function, performance, size, and power consumption advantages when compared to optocouplers. The ISO1540 and ISO1541 devices enable a complete isolated I2C interface to be implemented within a small form factor.

The ISO1540 has two isolated bidirectional channels for clock and data lines while the ISO1541 has a bidirectional data and a unidirectional clock channel. The ISO1541 is useful in applications that have a single Master while the ISO1540 is ideally fit for multi-master applications.

Isolated bidirectional communications is accomplished within these devices by offsetting the Side 1 Low-Level Output Voltage to a value greater than the Side 1 High-Level Input Voltage, thus preventing an internal logic latch that otherwise would occur with standard digital isolators.


  • Isolated Bidirectional, I2C Compatible,
  • Supports up to 1-MHz Operation
  • 3-V to 5.5-V Supply Range
  • Open-Drain Outputs With 3.5-mA Side 1 and 35-
    mA Side 2 Sink Current Capability
  • –40°C to +125°C Operating Temperature
  • ±50-kV/µs Transient Immunity (Typical)
  • HBM ESD Protection of 4 kV on All Pins;
    8 kV on Bus Pins
  • Safety and Regulatory Approvals
    • 4242-VPK Isolation per DIN V VDE V 0884-10
      (VDE V 0884-10): 2006-12
    • 2500-VRMS Isolation for 1 Minute per UL 1577
    • CSA Component Acceptance Notice 5A, IEC
      60950-1 and IEC 61010-1 End Equipment
    • CQC Basic Insulation per GB4943.1-2011

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Parametrics Compare all products in Isolated I2C

UL 1577 Isolation Voltage (Single) (Vrms)
DIN V VDE V 0884-10 Transient Overvoltage Rating (Vpk)
DIN V VDE V 0884-10 Surge Voltage Rating (Vpk)
DIN V VDE V 0884-10 Working Voltage (Vpk)
CSA Isolation Rating (Vrms)
CSA 60950-1 Basic Working (Vrms)
CSA 61010-1 Basic Working (Vrms)
CSA 61010-1 Reinforced Working (Vrms)
Datarate (Mbps)
Number of Channels (#)
Serial Clock
Serial Data
Operating Temperature Range (C)
Approx. Price (US$)
ISO1540 ISO1541
2500    2500   
4242    4242   
4000    4000   
566    560   
2800    2800   
390    390   
300    300   
150    150   
1    1   
2    2   
Bi-directional    Uni-directional   
Bi-directional    Bi-directional   
-40 to 125    -40 to 125   
8SOIC    8SOIC   
2.00 | 1ku    1.80 | 1ku