The AD8212 is a high common-mode voltage, current shunt monitor. It accurately amplifies a small differential input voltage in the presence of large common-mode voltages up to 65 V (>500 V with an external PNP transistor). The AD8212 is ideal for current monitoring across a shunt resistor in applications controlling loads, such as motor controls, DC-to-DC converters, power supplies, battery monitoring, and remote sensing.
The AD8212 high‑voltage current shunt monitor amplifies a small differential voltage across a shunt resistor while tolerating large common‑mode voltages. Features include adjustable gain, an integrated 5 V regulator, and a patented output base‑current compensation circuit for high‑voltage operation.
The device is supplied in an 8‑lead MSOP package and is specified for supply voltages from 7 V to 65 V in normal mode, or up to >500 V when used with an external high‑voltage PNP transistor. Detailed electrical specifications, pin descriptions, and typical performance curves are provided.
| Supply Voltage (V+) | 7 V to 65 V (no external pass transistor) |
|---|---|
| Supply Voltage (V+) with external PNP | 7 V to >500 V |
| Supply Current (Isup) | 220 pA to 720 pA (normal) |
| Supply Current (Isup) high‑voltage mode | 200 pA to 1500 pA |
| Input Impedance (Differential) | 2 kΩ |
| Common‑Mode Input Impedance | 5 MΩ |
| Differential Voltage Range | 500 mV |
| Operating Temperature Range | -20 °C to +125 °C |
| PSRR | 80 dB |
| Bias Current (normal) | 185 pA to 200 pA |
The AD8212 operates with a supply voltage from 7 V to 65 V when no external pass transistor is used.
By adding an external high‑voltage breakdown PNP transistor, the common‑mode range can be extended to over 500 V.
The differential input impedance is specified as 2 kΩ.