International Test Instruments Corporation IR21771STRPBF

Overview

IR21771STRPBF from Infineon Technologies is a high-voltage, high-speed single-phase current sensor IC for AC motor drives, featuring floating channel operation up to 600 V, ±250 mV input range, <7.5 µs sensing latency at 20 kHz, 40 ksample/sec throughput, and digital PWM output with fast overcurrent detection. It interfaces with external shunt resistors and supports bootstrap power supplies.

For engineers reviewing the IR21771STRPBF datasheet, IR21771STRPBF pinout, IR21771STRPBF application, or IR21771STRPBF equivalent, this device is selected for precision phase current sensing in variable-frequency drives where low-latency, high-noise-rejection analog-to-time conversion and integrated IGBT protection are required.

Technical Context

The IR21771STRPBF implements a synchronous sampling measurement system that converts differential shunt voltage into a duty-cycle-modulated PWM signal via precise analog integration and level-shifting. Its group delay is ≤4 µs and common-mode rejection is 0.2 m%/V at VS–VSS = 600 V, enabling stable operation under high dVS/dt (up to 50 V/ns).

It uses dual gain-select pins (G0/G1) to configure integrator range, delivers open-drain OC and PO outputs with 25–75 Ω on-resistance, and requires external pull-ups to VCC (8–20 V). The sync input accepts 4–20 kHz TTL-compatible signals with 0.2 V hysteresis.

Key Specifications

Pinout & Package

IR21771STRPBF is housed in a 16-pin SOIC wide-body (SOIC16WB) package with creepage-enhanced spacing for 600 V isolation. Pin 2, 4, 5, and 9 are NC; all other pins are electrically assigned per lead definitions.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar high-voltage current sensing applications.

Compared with IR22771STRPBF and AMC1301DWVR, IR21771STRPBF offers optimal balance of cost, latency, and integration for 600 V industrial drives-providing native OC signaling and bootstrap compatibility without isolation overhead or external filtering.

Availability

IR21771STRPBF is available at Aetrix Electronics and suitable for industrial variable-frequency drives, appliance motor controllers, and e-bike power stages requiring stable component supply, consistent parametric performance, and long-term production continuity.

Supply support for IR21771STRPBF includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Infineon Technologies is a German semiconductor manufacturer specializing in power management, automotive, and industrial control ICs, with leadership in high-voltage gate drivers and sensor interfaces.

The IR21771STRPBF belongs to Infineon's high-voltage current sensor product line, designed specifically for robust, low-latency phase current measurement in cost-sensitive AC motor drives using shunt-based sensing.

FAQ

What is the maximum allowable dVS/dt for reliable operation?

The IR21771STRPBF is rated for 50 V/ns dVS/dt under recommended operating conditions. This specification ensures stable operation during fast IGBT or Si-MOSFET switching transitions in 600 V inverters. Exceeding this limit may degrade common-mode rejection or introduce timing jitter in the PWM output. Layout best practices-including minimized VS loop area and symmetric routing of VIN+/VIN−-are critical to maintain this rating in practice.

How does the G0/G1 pin configuration affect full-scale range?

G0 and G1 are binary-coded gain select inputs tied to VB or VS to set integrator gain: G1G0 = 00 → ×1 (±250 mV), 01 → ×2 (±125 mV), 10 → ×4 (±62.5 mV), 11 → ×8 (±31.25 mV). This allows matching the IC's input range to shunt resistor value and expected current magnitude without external amplification. Gain selection is latched at power-up and remains fixed until reset.

Can the OC output be used to directly disable an IGBT gate driver?

Yes-the OC pin is an open-drain output with 25–75 Ω on-resistance and supports direct connection to enable/disable inputs of compatible gate drivers (e.g., IR21xx families). When asserted, it pulls low within 3.5 µs and holds until PO is forced low (via TOCoff = 0.5 µs). No external logic is needed, but a pull-up resistor to VCC is required per datasheet Note 2.

Is external filtering required on the Sync input?

No external filtering is required on the Sync input. The internal Schmitt trigger provides 0.2 V hysteresis and is designed to accept clean 4–20 kHz square-wave signals directly from MCU timers or DSP outputs. However, if routed near noisy power traces, a small RC filter (e.g., 100 Ω + 100 pF) may improve noise immunity without affecting timing-provided group delay remains below 100 ns.