Dual-Output, 4A and 6A/Phase, Highly Integrated SupIRBuck™ Single Input Voltage, Synchronous Buck Regulator



The IR3891/92 SupIRBuck are easy to use, fully integrated and highly efficient DC/DC regulators. The on-board PWM controller and MOSFETs make them a space efficient solution, providing accurate power delivery for low output voltage.

They are versatile regulators which offer programmability of switching frequency and a fixed current limit while operating in wide input and output voltage range.

The switching frequency is programmable from 300kHz to 1.5MHz (IR3891)/1.0MHz (IR3892) for an optimum solution.

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 165mm2 (46% smaller than traditional designs that utilize two 6A single output converters).

They also feature important protection functions, such as over-voltage protection (OVP), pre-bias start-up, hiccup current limit and thermal shutdown to give required system level security in the event of fault conditions.


• Single 5V to 21V application
• Wide input voltage range from 1V to 21V with external VCC
• Output voltage range: 0.5V to 0.86*PVIN
• Dual output, 4A phase (IR3891)/6A phase (IR3892)
• Programmable switching frequency up to 1.5MHz (IR3891)/1.0MHz (IR3892)
• Internal digital soft start
• Thermally compensated current limit and hiccup mode overcurrent protection
• External synchronization with smooth clocking
• Precision reference voltage (0.5V ±1%)
• Sequence pin for sequencing applications
• Integrated MOSFETs, drivers and bootstrap diode
• Thermal shutdown
• Open feedback line protection
• Over-voltage protection
• Interleaved phases to reduce input capacitors
• Operating junction temp: -40°C<TJ<125°C
• Small size 5 x 6mm PQFN

• Server
• Netcom
• Set top box
• Storage
• Embedded telecom systems
• Distributed point-of-load power architectures
• Computing peripheral voltage regulators
• General DC/DC converters


IR3891: Efficiency [VIN=12V, Fsw=600kHz]


IR3892: Efficiency [VIN=12V, Fsw=600kHz]

Part NumberIOUT (A)Switching Frequency (kHz)Package (mm)Circuit TypeVIN Range (V)VOUT Range (V)
IR3891MTRPBF4A/Ch300 - 1,500PQFN 5 x 6Dual Output1 - 210.5 - 86%VIN
IR3892MTRPBF6A/Ch300 - 1,000PQFN 5 x 6Dual Output1 - 210.5 - 86%VIN