Industry’s smallest 2.5 kV rms digital isolation devices

2nd October 2013

Nat Bowers

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Datasheet

Texas Instruments introduce 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 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 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.

Key features and benefits of the ISO71xx devices:

2.5 times higher galvanic isolation rating: Boast an impressive 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.
Smallest package: Offered in16-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.
Up to 2.5 times higher transient immunity: With a typical common-mode transient immunity of +/-75 kV/us, these isolation devices provide better immunity in noisy industrial environments, compared to competitive devices that are rated at +/-25 kV/us or +/-50 kV/us.
Flexibility with power supplies: Provide 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 control signal to cross the isolation barrier from one side and drive power semiconductor switches on the other side with short propagation delays.

Tools and support

The low-power digital isolation evaluation module is available to evaluate the isolator performance and parameter using the ISO71xx family. It can be ordered today for US$79.

Availability, packaging and pricing

The triple ISO7131CC and quad ISO7140FCC, ISO7140CC, ISO7141FCC, ISO7141CC and ISO7142CC devices are available in 16-pin, 5- by 6-mm QSOP packages. Suggested retail pricing in 1,000-unit quantities starts at US$1.60.