Bidirectional, Zero-Drift, Current Sense Amplifier

The AD8418 is a high voltage, high resolution current shunt amplifier. It features an initial gain of 20 V/V, with a maximum ±0.15% gain error over the entire temperature range. The buffered output voltage directly interfaces with any typical converter. The AD8418 offers excellent input common-mode rejection from −2 V to +70 V. The AD8418 performs bidirectional current measurements across a shunt resistor in a variety of automotive and industrial applications, including motor control, battery management, and solenoid control.

The AD8418 offers breakthrough performance throughout the −40°C to +125°C temperature range. It features a zero drift core, which leads to a typical offset drift of 0.1 μV/°C throughout the operating temperature range and the common-mode voltage range. The AD8418 is fully qualified for automotive applications and includes EMI filters and patented circuitry to enable output accuracy with pulse-width modulation (PWM) type input common-mode voltages. The typical input offset voltage is ±200 μV. The AD8418 is offered in 8-lead MSOP and SOIC packages.

Applications

* High-side current sensing in

Motor controls

Solenoid controls

Power management

* Low-side current sensing

* Diagnostic protection

* Typical 0.1 μV/°C offset drift

* Maximum ±400 μV voltage offset over full temperature range

* 2.7 V to 5.5 V power supply operating range

* Electromagnetic interference (EMI) filters Included

* High common-mode input voltage range

−2 V to +70 V operating

−4 V to +85 V survival

* Initial gain = 20 V/V

* Wide operating temperature range:

−40°C to +125°C

* Bidirectional operation

* Available in 8-lead SOIC and 8-lead MSOP

* Common-mode rejection ratio (CMRR): 86 dB, dc to 10 kHz

* Qualified for automotive applications