Datasheet ISL81801 80V Bidirectional 4-Switch Synchronous Buck-Boost Controller The ISL81801 is a true bidirectional 4-switch Features synchronous buck-boost controller with peak and Single inductor 4-switch buck-boost controller average current sensing and monitoring at both ends. On-the-fly bidirectional operation with independent With wide input and output voltage ranges, the control of voltage and current on both ends controller is suitable for industrial, telecommunication, and after-market automotive applications. Proprietary algorithm for smoothest mode transition The ISL81801 uses a proprietary buck-boost control MOSFET drivers with adaptive shoot-through algorithm with valley current modulation for Boost protection mode and peak current modulation for Buck mode Wide input voltage range: 4.5V to 80V control. Wide output voltage range: 0.8V to 80V The ISL81801 has four independent control loops for Supports startup into pre-biased rails input and output voltages and currents. Inherent peak current sensing at both ends and cycle-by-cycle Programmable frequency: 100kHz to 600kHz current limit of this family of products ensures high Supports parallel operation current sharing with operational reliability by providing instant current limit cascade phase interleaving in fast transient conditions at either end and in both directions. It also has two current monitoring pins at External sync with clock out or frequency dithering both input and output to facilitate Constant Current External bias for higher efficiency for 8V to 36V input (CC) limit and other system management functions. Output and input current monitor CC operation down to low voltages avoids any runaway condition at over load or short-circuit Selectable PWM mode operation between conditions. In addition to multilayer overcurrent PWM/DE/Burst modes protection, it also provides full protection features Accurate EN/UVLO and PGOOD indicator such as OVP, UVP, OTP, average and peak current limit on both input and output to ensure high reliability Low shutdown current: 2.7A in both unidirectional and bidirectional operation. Complete protection: OCP, SCP, OVP, OTP, and UVP The IC is packaged in a space-conscious 32 LD Dual-level OCP with average current and 5mm x5mm TQFN package or easy to assemble pulse-by-pulse peak current limit, also provides 4.4mmx9.7mm 38 LD HTSSOP package. Both Short Circuit Protection (SCP) packages use an EPAD to improve thermal Selectable OCP response with either hiccup or performance and noise immunity. Low pin count, constant current mode fewer external components, and default internal values make the ISL81801 an ideal solution for time Negative pulse-by-pulse peak current limit to market simple power supply designs. The unique Applications DE/Burst mode at light-load dramatically lowers standby power consumption with consistent output Battery backup ripple over different load levels. UPS/storage systems Battery powered industrial applications Renewable energy Aftermarket automotive Redundant power supplies Robots and drones Medical equipment Building and industrial automation Security surveillance FN8937 Rev.1.2 Page 1 of 49 Jun 2, 2021 2020 Renesas ElectronicsISL81801 VIN FB IN VOUT VDD BOOT1 VDD PGND UG1 VCC5V PHASE1 IMON IN LG1/ ISL81801 TQFN PWM MODE IMON OUT SGND LG2/ PLL COMP OC MODE RT/SYNC PHASE2 SS/TRK UG2 COMP VDD FB OUT BOOT2 Figure 1. Typical Application Diagram 100 90 80 70 R R s in V s out V IN OUT 60 Q UG2 Q UG1 1 4 L 50 PH1 PH2 Vin = 9V Vin = 12V Vin = 24V Vin = 36V 40 Vin = 48V Vin = 60V Q Q 2 3 LG1 LG2 Vin = 80V 30 02468 10 I (A) OUT Figure 2. Buck-Boost Power Train Topology Figure 3. Efficiency (V = 12V, DE Mode) OUT FN8937 Rev.1.2 Page 2 of 49 Jun 2, 2021 CLKOUT/DITHER BSTEN CLKEN OV EN/UVLO PGOOD EXTBIAS VIN CS+ ISEN- ISEN+ CS- Efficiency (%)