Renesas Electronics has announced an innovative new family of bi-directional four-switch synchronous buck-boost controllers.
The ISL81601 and ISL81401 are the industry’s only true bi-directional controllers that sense peak current at both ends and provide cycle-by-cycle current limiting in both directions while in buck or boost mode. They generate Point-of-Load (PoL) power supplies at a peak efficiency of up to 99%.
The ISL81601 has a wide input-voltage range of 4.5V to 60V and produces a 0.8V to 60V output. This is compatible with most industrial batteries, which typically operate at 12V, 24V, 36V or 48V. Also available is the ISL81401, which has a 4.5V to 40V input range and 0.8V to 40V output range, and a unidirectional counterpart, the ISL81401A.
The ISL81601 and ISL81401’s bi-directional peak current-sensing capability eliminates the complex external circuitry required for charging and discharging a battery that supplies power to loads. Their proprietary algorithm provides smooth transitions between buck, boost and buck-boost modes, while reducing low-frequency ripple at the output. This produces minimal disturbance during line or load transients. The algorithm also maintains a predictable ripple voltage under all conditions.
Designers can easily expand system power by paralleling an unlimited number of controllers. The ISL81601 and ISL81401 operate two switches at a time to minimize power loss and achieve higher efficiency.