Infineon Technologies AUIRS21281S

Overview

AUIRS21281S from Infineon Technologies (formerly International Rectifier) is an automotive-grade, high-voltage, single-channel IGBT/MOSFET gate driver with integrated desaturation over-current protection and inverting logic output. It operates up to +600 V offset voltage, delivers 290 mA source / 600 mA sink peak output current, and features 200 ns turn-on / 175 ns turn-off propagation delays. It is used in high-side IGBT drive circuits for electric power steering and hydraulic pump inverters.

For engineers reviewing the AUIRS21281S datasheet, AUIRS21281S pinout, AUIRS21281S application, or AUIRS21281S equivalent, key selection criteria include its AEC-Q100 qualification, 9–20 V automotive gate drive range, desaturation detection threshold (1.5–2.1 V), FAULT open-drain reporting, and SOIC-8 package with floating channel capability.

Technical Context

The AUIRS21281S integrates a latch-immune HVIC process with CMOS logic to enable robust high-side switching up to 600 V. Its desaturation protection monitors the V_CE sense voltage via the CS pin with a 1.5–2.1 V threshold and triggers FAULT within ≤360 ns after over-current detection.

It uses bootstrap operation for high-side drive, supports 3.3 V/5 V/15 V logic inputs, and implements undervoltage lockout on both V_BS (6.0–7.7 V hysteresis) and V_CC. The output is inverted relative to input - critical for complementary half-bridge control in three-phase motor drives.

Key Specifications

Pinout & Package

Supplied in an 8-lead SOIC package with standard JEDEC MS-012AC footprint and creepage/clearance compliant for 600 V isolation. Pin 1 marked by dot; pins 4 (COM) and 6 (VS) are internally connected to substrate for thermal and noise control.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar high-voltage, desaturation-protected gate driver applications.

Compared with IR2128S, AUIRS21281S adds automotive qualification and lower V_BS UVLO for wider bootstrap margin in 12 V systems; versus UCC21520QDWKQ1, it trades isolation and speed for integrated desat protection and cost-effective SOIC packaging.

Availability

AUIRS21281S is available at Aetrix Electronics and suitable for electric power steering, hydraulic pump inverters, and forklift traction systems requiring stable component supply across extended automotive product lifecycles.

Supply support for AUIRS21281S 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 electronics, and industrial control ICs, with global manufacturing and qualification infrastructure.

The AUIR-series high-voltage gate drivers were developed specifically for automotive traction and auxiliary inverters, emphasizing robustness under high dV/dt, integrated protection, and AEC-Q100 compliance.

FAQ

What is the purpose of the FAULT pin on AUIRS21281S?

The FAULT pin is an open-drain output that pulls low when desaturation over-current protection activates. It requires an external pull-up resistor to V_CC and interfaces directly with microcontroller interrupt or GPIO pins to trigger immediate PWM disable and system fault logging. Its propagation delay from CS event to FAULT assertion is ≤510 ns.

Can AUIRS21281S drive SiC MOSFETs?

Yes - its 9–20 V gate drive range, 600 mA sink current, and 200 ns propagation delay support common SiC MOSFET gate requirements. However, its desaturation threshold (1.5–2.1 V) is optimized for IGBT V_CE(sat); for SiC, external scaling of the CS resistor divider may be needed to match V_DS trip levels.

How does the bootstrap configuration work with AUIRS21281S?

The V_BS pin connects to a bootstrap capacitor charged through an external diode when the low-side switch is on. During high-side conduction, the capacitor supplies the floating output stage. The internal V_BS UVLO (6.3–8.2 V) disables output if capacitor voltage drops too low, preventing weak gate drive and shoot-through risk.

Is AUIRS21281S pin-compatible with AUIRS21271S?

Yes - both share identical SOIC-8 pinout and package. The key functional difference is logic polarity: AUIRS21281S has inverting output (OUT = NOT IN), while AUIRS21271S is non-inverting. Swapping them requires inverting the input signal or adjusting firmware logic to maintain correct half-bridge timing.