This is information on a product in full production.
June 2016 DocID029495 Rev 1 1/20
SRK2001A
Adaptive synchronous rectification controller for LLC resonant
converter
Datasheet - production data
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 µA quiescent
current
V
CC
operating voltage range 4.5 V to 32 V
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
Description
The SRK2001A controller implements a control
scheme specific for secondary side synchronous
rectification in LLC resonant converters that use a
transformer with center tap secondary winding for
full wave rectification.
It provides two high current gate drive outputs,
each capable of directly driving N-channel power
MOSFETs. Each gate driver is controlled
separately and an interlock logic circuit prevents
the two synchronous rectifier MOSFETs from
conducting simultaneously.
The driver high-level voltage is clamped to 11 V in
order to avoid providing excessive gate charge to
SR MOSFETs, in case the device is supplied at
higher VCC voltages.
The control scheme in this IC provides for each
synchronous rectifier being switched on as the
corresponding half-winding starts conducting and
switched off as its current goes 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 MOSFETs, eliminating the need of
the parasitic inductance compensation circuit.
The low consumption mode of the device allows
to meet the most stringent requirement for
converter power consumption in light-load and no
load conditions.
A noticeable feature is the very low external
component count required.
Table 1. Order codes
Part number Package Packing
SRK2001A
SSO10P
Tube
SRK2001ATR Tape and reel
www.st.com
