IR22771S/IR21771S is a single phase current sensor interface IC produced by IR company. It is suitable for AC motor drive applications. The IC has floating channel, high PWM noise rejection capability, digital PWM output, fast over current detection, low latency and other features.
The IR22771S and IR21771S are high‑voltage, high‑speed single‑phase current sensor interfaces designed for AC motor drive applications. They sense current via an external shunt resistor and convert the analog voltage into a time‑interval output, offering synchronous sampling, low latency, and fast over‑current detection.
The document lists absolute maximum ratings, recommended operating conditions, pin assignments, timing diagrams, PCB layout recommendations, and mechanical dimensions. It also includes guidelines for bootstrap capacitor selection and grounding to minimize noise coupling in high‑voltage designs.
| Low sensing latency | <7.5 µs @20 kHz |
|---|---|
| Throughput | 40 k samples/sec |
| Over Current threshold | +470 mV |
| Bootstrap supply range | 8‑20 V |
| Maximum power dissipation | 250 mW |
| Thermal resistance (junction‑to‑ambient) | 90 °C/W |
| Operating temperature range | -40 °C to 125 °C |
Use a low‑ESR solution, typically a parallel combination of a small ceramic capacitor and a large electrolytic capacitor.
The device can process up to 40 k samples per second.
The ground plane must NOT be placed under or near the high‑voltage floating side to reduce noise coupling.