ADI current sense amp claims highest accuracy

Norwood, Mass. — Analog Devices, Inc. (ADI) has claimed the industry’s most accurate high-voltage amplifier for current sensing applications. The AD8207 zero-drift, high-voltage, bi-directional current sense amplifier meets the performance and quality requirements for motor and solenoid control in industrial and automotive applications.

The product features breakthrough temperature accuracy specified at a maximum of 1 μV/°C offset drift over the automotive temperature range of -40 degrees C to 125 degrees C — a 5-fold improvement over competing devices, according to ADI. Click here for a video on the AD8207.

The AD8207 is said to offer the lowest guaranteed offset drift, coupled with greater than 150-kHz bandwidth, and maximum 0.3 percent gain error. The device provides low-drift current measurement for closed-loop motor control in safety critical automotive applications, such as electric power steering and advanced braking, and enables accurate current measurements to control solenoids and actuators in industrial applications.

The unique architecture of the AD8207 accurately amplifies small differential current shunt voltages in the presence of rapidly changing common-mode voltages ranging from -4 V to 65 V, said ADI. The current sense amplifier rejects pulse width modulation (PWM) input common-mode voltages, while the zero-drift architecture yields the lowest offset drift performance available today, according to the company.

Steve Sockolov, director, Precision Signal Conditioning Group, Analog Devices, said the AD8207 is the “only zero-drift current sense amplifier with high bandwidth and a common-mode voltage range that extends below ground.”

Here are key specs:

  • Input common-mode voltage range:
    -4 V to +65 V operating (5 V supply)
    -4 V to +35 V operating (3.3 V supply)
    -25 V to +75 V input survival

  • Offset drift is typically less than 500 nV/ degrees C and gain drift is below 10 ppm/ degrees C.
  • 80 dB common-mode rejection ratio (CMRR) from dc to 100 kHz.
  • Meets AEC-Q100 standards and is tested for electromagnetic interference (EMI) compliance.
  • Adjustable output offset is effective for bi-directional current measurements.

As part of a signal chain, ADI says the AD8207 works well with the AD8214 high-voltage threshold detector and ADI’s resolver-to-digital converters, such as the AD2S80A variable resolution resolver-to-digital converter and the AD2S44 14-bit, dual-channel synchro/resolver-to-digital converter.

Availability: Samples are available for the AD8207WBRZ (8-lead SOIC), AD8207WBRZ-RL (8-lead SOIC, 13-in. tape/reel) and AD8207WBRZ-R7 (8-lead SOIC,
7-in. tape/reel)
Pricing: $1.99 each in quantities of 1,000.
Resources: datasheet, amplifier product info, motor control apps and automotive apps.