Renesas ISL81801/ISL81802

The ISL81801 will be the lead part and is an industry-first 80V on-the-fly bidirectional 4-switch synchronous buck-boost controller with constant voltage and constant current regulation. It joins the ISL81601 (60V) and ISL81401 (40V) in the high voltage bidirectional buck boost controller family. The ISL81802 is an industry-first 80V dual output/two-phase synchronous buck controller with up to 1MHz operation and current sharing, and is suitable for higher power applications.

These devices target 48V telecom, data centre server & rugged industrial applications world-wide.

ISL81801

The ISL81801 is a true bidirectional 4-switch synchronous buck-boost controller with peak and average current sensing and monitoring at both ends. With wide input and output voltage ranges, the controller is suitable for industrial, telecommunication, other industrial applications.

The ISL81801 uses a proprietary buck-boost control algorithm with valley current modulation for Boost mode and peak current modulation for Buck mode control.

The ISL81801 has four independent control loops for input and output voltages and currents. Inherent peak current sensing at both ends and cycle-by-cycle current limit of this family of products ensures high operational reliability by providing instant current limit in fast transient conditions at either end and in both directions. It also has two current monitoring pins at both input and output to facilitate Constant Current (CC) limit and other system management functions. CC operation down to low voltages avoids any runaway condition at over load or short-circuit conditions. In addition to multilayer overcurrent protection, it also provides full protection features such as OVP, UVP, OTP, average and peak current limit on both input and output to ensure high reliability in both unidirectional and bidirectional operation. The unique DE/Burst mode at light-load dramatically lowers standby power consumption with consistent output ripple over different load levels.

The IC is packaged in a space-conscious 32 LD 5mmx5mm TQFN package or easy to assemble 4.4mmx9.7mm 38 LD HTSSOP package. Both packages use an EPAD to improve thermal performance and noise immunity. Low pin count, fewer external components, and default internal values make the ISL81801 an ideal solution for time to market simple power supply designs.

ISL81802

The ISL81802 is a dual synchronous buck controller that generates two independent outputs or one output with two interleaved phases for a wide variety of applications in industrial and general purpose segments. With a wide input and output voltage ranges, the controller is suitable for telecommunication, data center, and computing applications.

The ISL81802 uses peak current mode control with phase interleaving for the two outputs. Each output has a voltage regulator, current monitor, and average current regulator to provide independent average voltage and current control. The internal Phase-Locked Loop (PLL) oscillator assures an accurate frequency setting from 100kHz to 1MHz, and the oscillator can be synchronized to an external clock signal for frequency synchronization and phase interleave paralleling applications. This PLL circuit can output a phase-shift-programmable clock signal that is expanded to three, four, and six phases with required interleaving phase shift.

The ISL81802 features programmable soft-start and accurate threshold enable functions along with a power-good indicator to simplify power supply rail sequencing. It also provides full protection features such as OVP, UVP, OTP, and average and peak current limit on both outputs to ensure high reliability.

The IC is packaged in a space-saving 32 Ld 5mmx5mm TQFN or an easy to assemble 4.4mmx9.7mm 38 Ld HTSSOP package. Both packages use an EPAD to improve thermal performance and noise immunity. The full feature design with low pin count makes the ISL81802 an ideal solution for quick time to market simple power supply designs.