Bidirectional, Zero-Drift, Current Sense Amplifier

The AD8418A 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 AD8418A offers excellent input common-mode rejection from −2 V to +70 V. The AD8418A performs bidirectional current measurements across a shunt resistor in a variety of automotive and industrial applications, including motor control, power management, and solenoid control.

The AD8418A offers breakthrough performance throughout the −40°C to +150°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 AD8418A is qualified for automotive applications. The device 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 ±100 μV. The AD8418A is offered in an 8-lead MSOP and an 8-lead SOICN package with a 10-lead MSOP pinout option engineered for failure mode and effects analysis (FMEA).

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 ±200 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, continuous operation

* −3 V to +80 V, continuous survival

* Minimum DC common-mode rejection ratio (CMRR): 90 dB