SRK2001A

SRK2001A Datasheet Adaptive synchronous rectification controller for LLC resonant converter Features Secondary side synchronous rectification controller optimized for LLC resonant converter Dual gate driver for N-channel MOSFETs Adaptive turn-off logic Turn-on logic with adaptive masking time Auto-compensation of parasitic inductance Low consumption mode: 50 A quiescent current V operating voltage range 4.5 V to 32 V CC High voltage drain-to-source Kelvin sensing for each SR MOSFET Operating frequency up to 500 kHz Programmable exit load levels from burst- mode SSOP10 package Applications AC-DC adapters All-in-one PC High-end flat panel TV 80+/85+ compliant ATX SMPS 90+/92+ compliant SERVER SMPS Industrial SMPS Product status link SRK2001A Description Product summary The SRK2001A controller implements a control scheme specific for secondary side Order code SRK2001A SRK2001ATR synchronous rectification in LLC resonant converters that use a transformer with Package SSOP10 center tap secondary winding for full wave rectification. Tube Tape & Reel Packing It provides two high current gate drive outputs, each capable of directly driving N- channel power MOSFET. Each gate driver is controlled separately, and an interlock Product label logic circuit prevents the two synchronous rectifier MOSFET from conducting simultaneously. The driver high-level voltage is clamped to 11 V in order to avoid delivering excessive gate charge to the SR MOSFET when the device is supplied at higher VCC voltages. The control scheme ensures that each synchronous rectifier is switched ON as the corresponding half-winding starts conducting and OFF as its current falls to zero. The turn-on logic with adaptive masking time (up to 10% of clock cycle) and innovative adaptive turn-off logic allow maximizing the conduction time of the SR MOSFET, eliminating the need for a parasitic inductance compensation circuit. The low consumption mode of the device allows meeting the most stringent requirement for converter power consumption in light-load and no-load conditions. A very low external component count required when using this device. DS11726 - Rev 3 - September 2021 www.st.com For further information contact your local STMicroelectronics sales office.SRK2001A Block diagrams 1 Block diagrams Figure 1. Internal block diagram DVS1 UVLO VCC HV SVS1 CLAMP POWER and MANAGEMENT V BUS SWITCH GND DVS2 SVS2 TIMERS COMPARATORS ON ZCD OFF EN ADC ADAPTIVE ADAPTIVE PROG ON-TIME OFF-TIME CK CONTROL LOGIC DRIVER DRIVER GD2 GD1 Figure 2. Typical system block diagram PFC PRE-REGULATOR(OPTIONAL) LLC RESONANT HALF-BRIDGE WITH SYNCH RECTIFIER V OUT V INac L6562A L6599A SRK2001A L6563/S/H L6699 DS11726 - Rev 3 page 2/21