The ISL78226 is a 6-phase, bidirectional, synchronous PWM

controller designed to perform power conversion between 12V

and 48V buses up to 3.75kW at >95 conversion efficiency.

One ISL78226 supports both Buck and Boost power

conversion enabling a compact and robust design with

minimum components.

ISL78226 regulates both voltage and current to control power

transfer from bus to bus. The multiphase architecture uses

interleaved timing to support up to six parallel power stages

per ISL78226. By interleaving the power stages, the ripple

frequency is multiplied, reducing input and output ripple

voltage and current. Lower ripple results in fewer input/output

capacitors and therefore, lower component cost and smaller

circuit implementation.

The IC is designed to be interleaved in a master/slave

architecture to be scaleable for higher power. Also integrated

within the device is a dual-output Flyback controller that

generates both a 12V supply for the power stage FET drivers as

well as a 6V supply for the ISL78226 from either of the two

buses. A 200mA auxiliary linear regulator is provided to supply

a local microcontroller or interface devices.

A PMBus interface provides system control and diagnostics to

support functional safety requirements. This digital interface

offers the system controller the ability to program operating

modes, voltage and current limit warning, protection

thresholds, individual fault response, and rapid fault condition

detection.

Features

• 6-phase bidirectional synchronous 12V to 48V controller

• Master/slave architecture supports up to 4 ICs in parallel

• Voltage and current regulation

• Phase dropping facilitated with companion FET driver

• Average phase-to-phase current balancing

• Average current output with ±1.5 accuracy

• Supply and clock redundancy for functional safety

• Cycle-by-cycle peak current limiting

• Cycle-by-cycle negative current limiting

• Digitally programmable average current limit

• Analog/digital control of output voltage

• PMBus for status monitoring and fault response control

• Selectable phase dropping and diode emulation for

light-load efficiency improvement

• Comprehensive protection with selectable hiccup or

latch-off fault responses

• Digitally programmable warning and fault thresholds

• Dual-output Flyback controller

• 200mA adjustable output linear regulator

• 10mmx10mm 64-TQFP with exposed pad thermal interface

• AEC-Q100 Grade 1

Applications

• Automotive Bidirectional DC/DC Converter

• Bidirectional DC/DC for smart grid