Renesas Electronics Corporation has announced a new and innovative family of 4-switch bidirectional buck-boost synchronous controllers. The ISL81601 and ISL81401 are the industry's only true bidirectional controllers that sense peak current at both ends and provide cycle-by-cycle current limiting in both directions while in buck or boost mode. The bidirectional peak current sensing capability of the ISL81601 and ISL81401 eliminates the complex external circuitry required to charge and discharge a battery to power loads. Their patented algorithm provides smooth mode transitions between buck, boost, and buck-boost, while reducing low-frequency ripple at Vout, ensuring minimal disturbance during line or load transients. The algorithm also guarantees predictable ripple voltage under all conditions. The addition of multi-layer overcurrent protection and a precision control algorithm delivers constant current down to 0.1V at Vout for reliable operation. Designers can easily expand system power by paralleling an unlimited number of controllers. The ISL81601 and ISL81401 drive two switches simultaneously to minimize power loss and achieve greater efficiency.
Key features of ISL81601, ISL81401 and ISL81401A:
4-switch buck-boost single-inductor drivers;
Bidirectional operation (ISL81601 and ISL81401) with four feedback control loops;
Independent voltage and current feedback loop control;
Constant current/constant voltage profile for input and output;
Supports on-the-fly changes to parametric configurations using microcontrollers;
Programmable frequency: 100kHz to 600kHz;
MOSFET drivers with adaptive trip protection.
8V drive (ISL81601) and 5V drive (ISL81401/A) for optimized efficiency.
Light charge efficiency mode and 2.7µA quiescent current extend battery life.
Frequency dimming for lower EMI (ISL81601 and ISL81401).
Extensive multi-layer protection for overvoltage, undervoltage, overcurrent, overtemperature, and short circuit.
The ISL81601 and ISL81401/A can be combined with a Renesas RL78 microcontroller (MCU), or other MCUs, to program voltages, battery charge/discharge function, and bidirectional power flow on the fly. Designers can also use the PowerCompass™ tool to help them identify other power supply components that match their specific system requirements. Multiple power rails can be configured, and designers can perform high-level system analysis and generate custom reference design files in minutes.
