TI isolators improve transient immunity, switching performance
12/13/2012 9:06 AM EST
Texas Instruments Inc. has introduced a bidirectional isolator family compatible with I2C interfaces that it claims consumes as much as 38-percent lower power than competitive devices.
Each of the new ICs can replace a typical implementation of 16 or more discrete devices to isolate the I2C signal in industrial applications, according to TI. In addition, the ISO1540 and ISO1541 offer better transient immunity and faster switching times than optocouplers. This performance provides longer-lasting isolation in a variety of applications, such as power supplies, networking, telecommunications, Power over Ethernet (PoE) and battery management systems.
The ISO1540 and ISO1541 employ a unique capacitive isolation technology with a silicon dioxide barrier (SiO2) to separate logic input and output buffers. This approach extends the lifetime of the isolators by more than three times compared to optocouplers or magnetic isolators. The ISO1540 provides two isolated bidirectional channels for clock and data lines for use in applications that have multiple masters. The ISO1541 includes a bidirectional data and a unidirectional clock channel for use in single-master applications. The I2C isolator family joins TI’s portfolio of long-lifetime digital isolation products, including devices with isolated CAN or RS-485 interface; isolated amplifiers; or other isolated functions for industrial applications.
- Lowest power: With maximum current of less than 8.5 mA at 5 V, the ISO1540 and ISO1541 reduce power consumption by up to 38 percent compared to competitive ICs, reducing heat generation in industrial applications.
- Fastest switching time: Maximum propagation delay of 62 nanoseconds is 52-percent better than competitive ICs, enabling faster data transfer.
- Higher reliability: ± 50-kV/us typical transient immunity provides better reliability in harsh environments.
- Prevents internal logic latch: Isolated bidirectional communications is accomplished within these devices by employing an offset configuration that prevents device latch-up and ensures reliable operation.
The ISO1540 and ISO1541 are available in industry-standard, 8-pin SOIC packages. Suggested retail pricing in 1,000-unit quantities is US$2.00 and US$1.80, respectively.