TI unveils smallest 2.5-kVrms digital isolation devices

October 01, 2013 // By Paul Buckley
Texas Instruments (TI) has introduced the industry’s first family of digital isolation devices to offer the highest isolation rating, at 2.5 kV rms, in a small, 5- by 6-mm QSOP package.

The ISO71xx family is 50-percent smaller than traditional SOIC isolation devices and provides an isolation rating 2.5 times better than competitive devices in the same package. Reducing board space without compromising protection from lower isolation ratings or EFT surges is increasingly important in industrial automation applications, such as programmable logic controllers (PLCs) and sensors, and Fieldbus applications, such as DeviceNet, CAN and RS-485. The low-power ISO71xx family of isolation devices meets these demands by offering up to 2.5 times higher common-mode transient immunity and 30-percent better maximum working voltage, versus similar devices.

The family includes six triple and quad devices  based on integrated silicon dioxide capacitors and provide both resistance to electromagnetic interference (EMI) and lower EMI radiance to provide increased reliability in harsh environments. To further enhance performance, the devices incorporate a glitch filter to smooth operation at lower frequencies. And with a power rating of approximately 1 mA per channel, the new isolation devices enable low power in these environments.

The ISO71xx devices feature 2.5 kVrms isolation rating, compared to 1 kVrms offered by competitive devices in the same package. This results in higher-end performance in tight, space-constrained designs, such as PLCs and inverters.

The devices are offered in 16-pin QSOP packages, measuring 5- by 6-mm (30mm2), the devices reduce board space by up to 72 percent versus typical 16-pin SOIC packages.

With a typical common-mode transient immunity of +/-75 kV/us, the isolation devices provide better immunity in noisy industrial environments, compared to competitive devices that are rated at +/-25 kV/us or +/-50 kV/us.

The device provides support for 2.7-, 3.3- and 5-V power supplies, giving designers maximum flexibility in power supply design.

By combining the ISO71xx family with TI's wide portfolio of gate driver ICs, such as the UCC27531,  UCC27517 or UCC27211, it is possible for designers to build compact, high-speed, industrial automation systems and offline, isolated switch-mode power supplies where there is need for the PWM