Capacitive technology boosts magnetic immunity

Dual-channel digital isolators boast faster data transmission, higher magnetic immunity and longer life expectancy than competing devices.

Using the company's innovative capacitive isolation technology, Texas Instruments has introduced a new family of dual-channel digital isolators, featuring faster data transmission, higher magnetic immunity and longer life expectancy than competing devices.

The ISO7220 and ISO7221 improve system performance and reduce cost in high-voltage, noisy applications such as factory automation, process control, computer peripherals and data acquisition systems.

TI's capacitive technology enables magnetic immunity six orders of magnitude higher than existing inductive devices, providing immunity from external magnetic fields that frequently occur in the industrial environment and which can distort signal integrity.

In addition, these devices offer high immunity against data corruption due to fast voltage transients (up to 25kV/us).

The capacitive technology also provides galvanic isolation of up to 4000V and life expectancy of greater than 25 years (compared with 7-10 years for competing devices).

These are critical requirements in industrial applications where voltage surges can otherwise degrade device performance and lifetime.

Used in combination 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.

To facilitate PCB layout, the ISO7220 has two channels in the same direction and the ISO7221 has two channels in opposite directions.

The ISO722x family provides three speed options: 1, 25 and 150Mbit/s.

Other key specifications include 1ns channel-to-channel skew, 3ns part-to-part skew, 1ns jitter, 1ns pulsewidth distortion and 4kV ESD protection.

All devices support any combination of 3.3 or 5V supplies.

The ISO7220 and ISO7221 are available now from TI and authorised distributors in SOIC-8 packages.

Suggested resale pricing for both devices starts at US $0.95 in 1000-unit quantities.

An evaluation module is available.

In addition, triple- and quad-channel versions are sampling now with volume production scheduled for Q4 2007.

Back to top