IR21271STR Overview
The UMW IR21271STR is a high-voltage, high-speed gate driver IC for N-channel power MOSFETs and IGBTs, manufactured using UMW’s proprietary high-voltage integrated circuit (HVIC) process combined with latch-immune CMOS technology for ruggedised monolithic construction. The floating channel architecture allows the IR21271STR to drive a single N-channel switch in either high-side or low-side configuration, with the floating supply rail fully operational up to +300V above ground — making it compatible with half-bridge stages in motor drives, DC-DC converters, and inverter systems operating from rectified mains or high-voltage DC bus supplies. Input logic is compatible with standard CMOS, LSTTL, 3.3V, 5V, and 15V drive signals, eliminating the need for level-shifting circuitry in mixed-voltage system designs.
A key differentiator of the UMW IR21271STR is its integrated overcurrent protection (OCP) circuit, which monitors the driven power transistor — typically by sensing VCE(sat) or VDS during the on-state — and terminates gate drive immediately upon detecting an overcurrent condition. An open-drain FAULT output pin signals the fault event to the host microcontroller or supervisory circuit, enabling system-level fault logging, safe shutdown sequencing, or automatic restart attempts without the need for a discrete current sense comparator. The output driver features a high pulse current buffer stage designed to minimise cross-conduction during switching transitions, contributing to lower EMI and improved switching waveform integrity at high frequencies.
The IR21271STR operates from a gate drive supply of 8V to 22V, covering standard 12V, 15V, and 18V gate drive rails used across IGBT and MOSFET power stages. The device is housed in a compact SOP-8 package, footprint-compatible with the original Infineon IR21271 series it is designed to replace. UMW manufactures the IR21271STR to full RoHS compliance, and ABL Semi distributes it as a 100% authentic, original UMW factory product, with flexible MOQ and compliance documentation for UK and European customers seeking a cost-effective, fully traceable alternative to the Infineon original.
Key Specifications
| Parameter | Value |
|---|---|
| Device Type | High-Voltage High-Speed MOSFET / IGBT Gate Driver |
| Floating Channel Maximum Voltage | +300V |
| Gate Drive Supply Range | 8V to 22V |
| Logic Input Compatibility | 3.3V / 5V / 15V (CMOS and LSTTL compatible) |
| Driver Configuration | Single-channel — high-side or low-side N-channel |
| Output Stage | High pulse current buffer — minimum cross-conduction |
| Overcurrent Protection (OCP) | Integrated — terminates gate drive on detection |
| Fault Signalling | Open-drain FAULT output pin |
| HVIC Technology | Proprietary HVIC + latch-immune CMOS |
| Package | SOP-8 |
| RoHS Compliance | Yes |
Applications
The IR21271STR is suited to high-voltage switching applications requiring a single high-side or low-side N-channel gate driver with integrated overcurrent protection and fault signalling. Primary application areas include half-bridge and full-bridge motor drives, industrial inverters, synchronous rectifier stages, switch-mode power supplies (SMPS), and PFC boost converters. The device is equally well-matched to EV auxiliary converters, UPS inverter stages, and industrial servo drives, where the combination of 300V floating operation, multi-logic-level input compatibility, and on-chip OCP with FAULT output reduces system component count and simplifies protective circuit design.
Pin-to-Pin Compatible Alternatives
The UMW IR21271STR is designed as a direct pin-compatible replacement for the original Infineon IR21271, sharing the identical SOP-8 footprint and functional pinout used across the IR212xx high-side gate driver family — enabling zero-modification board-level substitution to reduce BOM cost and improve procurement flexibility.
| Reference Part Number | Original Manufacturer | Why Choose IR21271STR |
|---|---|---|
| IR21271 | Infineon (International Rectifier) | The original reference design this UMW device is built to replace; IR21271STR offers identical SOP-8 pinout, 300V floating operation, and integrated OCP at a significantly lower unit cost from ABL Semi stock |
| IRS21271 | Infineon (International Rectifier) | Surface-mount variant of the IR21271 series in SOP-8; IR21271STR provides direct footprint compatibility with equivalent overcurrent protection and FAULT output functionality |
| UCC27517 | Texas Instruments | Single-channel gate driver in SOT-23/SOP-8; IR21271STR adds integrated OCP and open-drain FAULT output, reducing external protection circuit requirements in IGBT-based designs |
| NCP5181 | onsemi | High/low-side gate driver in SOP-8; IR21271STR offers equivalent floating channel voltage rating with the addition of overcurrent detection and FAULT signalling for enhanced fault management |
| IXD_614 | IXYS (Littelfuse) | High-speed single-channel gate driver; IR21271STR provides comparable drive capability with the addition of 300V floating operation and integrated OCP — a more complete protection solution in the same SOP-8 package |
Frequently Asked Questions
Is IR21271STR RoHS compliant?
Yes. The IR21271STR is fully RoHS compliant. UMW manufactures the IR21271STR in accordance with EU RoHS Directive 2011/65/EU, ensuring the device is free from restricted hazardous substances including lead and mercury. ABL Semi can provide full compliance and trade documentation upon request to support UK and European regulatory and procurement requirements.
What are the pin-to-pin replacements for IR21271STR?
The IR21271STR is a direct pin-compatible replacement for the Infineon IR21271 and IRS21271, sharing an identical SOP-8 footprint and functional architecture, and is also functionally compatible with the TI UCC27517, onsemi NCP5181, and IXYS IXD_614 in comparable single-channel gate driver applications. Refer to the compatibility table above for a detailed comparison.
What is the minimum order quantity (MOQ) for IR21271STR?
ABL Semi offers flexible MOQ for IR21271STR, supporting both prototype quantities and mass production orders. Contact us for current stock and pricing.
What package options are available for IR21271STR?
The IR21271STR is available in the SOP-8 (small outline 8-pin) surface-mount package. This footprint is pin-compatible with the original Infineon IR21271 series and is the standard package used across the IR212xx gate driver family, enabling direct board-level substitution in existing PCB designs without any layout modification. Contact ABL Semi to confirm current stock availability.
How does the IR21271STR overcurrent protection work, and what external components are required?
The IR21271STR’s integrated overcurrent protection (OCP) operates by monitoring the collector-emitter saturation voltage (VCE(sat)) of a driven IGBT — or drain-source voltage (VDS) of a MOSFET — during the on-state via a dedicated sense pin. If the sensed voltage exceeds a threshold indicative of an overcurrent condition, the gate drive is terminated within nanoseconds to prevent device damage. A blanking capacitor connected to the sense pin is typically required to suppress false triggering during the initial turn-on transient, when VCE(sat) is temporarily elevated before the device fully enhances. The open-drain FAULT output then pulls low to signal the fault to the host controller, which can use this to implement a soft shutdown, fault latch, or retry sequence. Consult the UMW IR21271STR datasheet for recommended blanking capacitor values and sense resistor configurations for your specific power device.
For complete product specifications, please refer to: