International Rectifier introduced the IR3891 and IR3892 SupIRBuck integrated dual output voltage regulators designed for space-constrained netcom, server and storage applications.

The new dual output devices are optimized for single rail operation from 5V to 12V inputs or 1V to 21V input with external 5V bias. Available in a compact 5x6mm PQFN package, the IR3891 and IR3892 offer an ultra-compact solution for applications requiring up to 4A per channel and up to 6A per channel respectively in as little as 165 mm2

The IR3891 and IR3892 feature a proprietary modulator scheme that enables jitter-free and noise-free operation to allow higher frequency/higher bandwidth operation for better transient response and fewer output capacitors to reduce overall system size. Other key features include interleaved phases to reduce input capacitance, powertrain isolation to eliminate crosstalk and sequencing capability on channel two.

Offering the features and benefits of the SupIRBuck family, these new dual output devices offer an efficient ultra-compact solution to meet the demands of space constrained, lower power netcom, server and storage applications.

The IR3891 and IR3892 offer SupIRBuck standard features that include switching frequency up to 1.5MHz and 1.0Mhz respectively, pre-biased start-up, input voltage aware enable, over voltage protection, power good, optional true output voltage sensing for open line feedback and adjustable OVP, internal soft-start and minimum input voltage of 1.0V (with ext. bias) and operating junction temperatures of -40oC to 125oC.  This new device and the entire SupIRBuck family are industrial qualified ensuring robust designs for durable systems.



Part Number



Switching Frequency






VIN Range


VOUT Range (V)


4A / Ch

300 – 1,500



Dual Output

1 - 21

0.5 – 86%Vin


6A / Ch

300 – 1,000


Reference Design

Featured Part



VIN Range


VOUT Range


Switching Frequency (kHz)



4A / 4A


1.8 / 1.2




6A / 6A


Design Tools

Datasheets and application notes are posted on the International Rectifier website at The IRDC3891 and IRDC3892 SupIRBuck reference designs featuring the new devices are also offered. A SupIRBuck Excel spreadsheet design tool and Icepak thermal model are available to facilitate design in addition to a user friendly, interactive, web-based selection and simulation tool at

Price and availability

Pricing for the IR3891 and IR3892 begins at US $3.46 and US $3.56 each respectively in 100,000-unit quantities. Pricing for the IRDC3891 and IRDC3892 SupIRBuck reference designs start at US $29 per kit. Production orders are available immediately. Prices are subject to change.