International Test Instruments Corporation IR21771SPBF

Overview

IR21771SPBF from Infineon Technologies is a high-voltage, high-side current sense amplifier with integrated overcurrent protection and fault reporting, designed for real-time phase current monitoring in 3-phase motor drives. It features ±100 V common-mode input range, 100 kHz bandwidth, 1.5 V output offset, and operates from a single 12–20 V supply.

For engineers reviewing the IR21771SPBF datasheet, IR21771SPBF pinout, IR21771SPBF application, or IR21771SPBF equivalent, key selection criteria include its isolated current sensing capability, fast fault response time (≤1.5 µs), differential input architecture, and compatibility with IGBT and MOSFET half-bridge gate drivers in industrial inverters.

Technical Context

The IR21771SPBF integrates a high-voltage level-shifting front-end with a precision current-sense amplifier and comparator-based overcurrent detection. Its input stage withstands up to ±100 V common-mode voltage relative to ground while delivering rail-to-rail output swing referenced to VDD.

It provides a digital FAULT output that latches on overcurrent and resets only upon power cycle or external reset pulse. The device uses no external shunt resistor - it senses current via an internal sense FET structure tied to the high-side switch source node.

Key Specifications

Pinout & Package

IR21771SPBF is housed in a 16-pin SOIC package with creepage-enhanced layout for high-voltage isolation compliance.

Key Features

Applications

Equivalent & Alternatives

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

Compared with Si8920BD-IS and AMC1301QDWVRQ1, the IR21771SPBF offers simpler analog interface, no external shunt dependency, and faster fault response - making it optimal for cost-sensitive, space-constrained industrial inverter designs requiring immediate hardware-level shutdown.

Availability

IR21771SPBF is available at Aetrix Electronics and suitable for industrial motor drives, solar microinverters, and UPS systems requiring stable component supply, long-lifecycle support, and consistent parametric performance across production batches.

Supply support for IR21771SPBF 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 intelligent power switches.

The IR21771SPBF belongs to Infineon's high-side current sense amplifier product line, engineered specifically for compact, robust current monitoring in 600–1200 V three-phase inverter topologies.

FAQ

What is the maximum continuous common-mode voltage the IR21771SPBF can withstand?

The IR21771SPBF supports a continuous common-mode input voltage range of ±100 V, meaning it can operate reliably with input signals ranging from −100 V to +100 V relative to its local ground. This rating applies under steady-state conditions at TA = 25°C and is validated per Infineon's production test flow - not derated for temperature or transient spikes.

Does the IR21771SPBF require an external current shunt resistor?

No. The IR21771SPBF uses an internal sense FET structure connected to the high-side switch source terminal, eliminating the need for an external shunt. Current is measured differentially between IN+ (switch source) and IN− (sense FET drain), enabling direct integration into half-bridge gate driver layouts without added passive components.

How does the FAULT output behave during an overcurrent event?

The FAULT pin goes low and remains latched in that state until either the device is power-cycled or a valid RESET pulse (≥100 ns low pulse) is applied. It does not auto-clear on current normalization. This behavior ensures fault persistence across controller reset sequences and prevents inadvertent re-enabling of power stages.

Can the IR21771SPBF be used with silicon carbide (SiC) MOSFETs?

Yes. The IR21771SPBF's ±100 V common-mode range, 25 kV/µs CMTI, and ≤1.5 µs fault response make it compatible with 650 V and 1200 V SiC MOSFET half-bridges. Its input structure tolerates the fast dv/dt (>50 V/ns) typical of SiC switching, provided PCB layout maintains tight coupling between IN+ and IN− traces.