DATASHEET ISL81401, ISL81401A FN9310 Rev.1.0 40V 4-Switch Synchronous Buck-Boost Controller May 28, 2021 The ISL81401 and ISL81401A are 4-switch synchronous Features buck-boost controller with peak and average current Single inductor 4-switch buck-boost controller sensing and monitoring at both ends. The ISL81401 is a On-the-fly bidirectional operation with independent bidirectional device that can conduct current in both control of voltage and current on both ends directions while the ISL81401A is an unidirectional device. Proprietary algorithm for smoothest mode transition The ISL81401 and ISL81401A use the proprietary MOSFET drivers with adaptive shoot-through buck-boost control algorithm with valley current protection modulation for Boost mode and peak current modulation Wide input voltage range: 4.5V to 40V for Buck mode control. Wide output voltage range: 0.8V to 40V The ISL81401 and ISL81401A have four independent control loops for input and output voltages and currents. Supports pre-biased output with SR soft-start Inherent peak current sensing at both ends and Programmable frequency: 100kHz to 600kHz cycle-by-cycle current limit of this family of products Supports parallel operation current sharing with ensures high operational reliability by providing instant cascade phase interleaving current limit in fast transient conditions at either ends and in both directions. It also has two current monitoring pins External sync with clock out or frequency dithering at both input and output to facilitate Constant Current External bias for higher efficiency supports 5V - 36V (CC) limit and other system management functions. CC input operation down to low voltages avoids any runaway condition at over load or short-circuit conditions. In Output and input current monitor addition to multilayer overcurrent protection, it also Selectable PWM mode operation between provides full protection features such as OVP, UVP, OTP, PWM/DE/Burst modes and average and peak current limit on both input and Accurate EN/UVLO and PGOOD indicator output to ensure high reliability in both unidirectional and bidirectional operation. Low shut down current: 2.7A The IC is packaged in a space conscious 32 Ld Complete protection: OCP, SCP, OVP, OTP, and UVP 5mmx5mm QFN package to improve thermal dissipation Dual-level OCP protection with average current and noise immunity. The unique DE/Burst mode at and pulse-by-pulse peak current limit light-load dramatically lowers standby power consumption with consistent output ripple over different Selectable OCP response with either hiccup or load levels. constant current mode Negative pulse-by-pulse peak current limit R R s out s in VIN VOUT Applications Battery backup Q1 Q4 UG2 UG1 L Type-C power supply and chargers PH1 PH2 Battery powered industrial applications Q2 Q3 LG1 LG2 Aftermarket automotive Redundant power supplies Robot and drones Figure 1. Buck-Boost Power Train Topology Medical equipment Security surveillance FN9310 Rev.1.0 Page 1 of 46 May 28, 2021 2018 Renesas Electronics&6 ,6( 1 &6 ,6( 1 9,1 ( 7 %, 6 3* 22 (1 89 /2 ,7 +(5 ISL81401, ISL81401A 7 B,1 )% 27 %2 8* ,6/ 4)1 /* 7 03 /B&2 3/ & . 8* 03 &2 7 B28 )% 27 %2 Figure 2. Typical Application Diagram 100 98 96 94 92 90 88 VIN = 6V VIN = 9V 86 VIN = 12V VIN = 24V 84 VIN = 36V 82 0123456789 I (A) OUT Figure 3. Efficiency (V = 12V, CCM) OUT FN9310 Rev.1.0 Page 2 of 46 May 28, 2021 .287 &/ ( 02 Efficiency (%) 9 66 75 3+ 6( 57 6<1 2& B02 ( /* 6* 1 ,02 1B28 ,02 1B,1 3+ 6( 9& & 9 3* 1 9 9 928 9,1