SRK2000A Datasheet, PDF (1/19 Pages) STMicroelectronics – Matched turn-off thresholds

SRK2000A
Synchronous rectifier smart driver for LLC resonant converters
SO-8
Features
 Secondary side synchronous rectifier controller
optimized for LLC resonant converters
 Protection against current reversal
 Safe management of load transient, light load
and startup condition
 Matched turn-off thresholds
 Intelligent automatic sleep mode at light load
 Dual gate driver for N-channel MOSFETs with
1 A source and 3.5 A sink drive current
 Operating voltage range 4.5 to 32 V
 Programmable UVLO with hysteresis
 250 µA quiescent consumption
 Operating frequency up to 500 kHz
 Available in SO-8 package
Applications
 All-in-one PC
 High-power AC-DC adapters
 80+/85+ compliant ATX SMPS
 90+/92+ compliant server SMPS
 Industrial SMPS
Datasheet - production data
Description
The SRK2000A smart driver implements a control
scheme specific to 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 driving one or more N-channel
Power MOSFETs. Each gate driver is controlled
separately and an interlocking logic circuit
prevents the two synchronous rectifier MOSFETs
from conducting simultaneously.
The control scheme in this IC allows for each
synchronous rectifier to be switched on as the
corresponding half-winding starts conducting and
switched off as its current goes to zero. The
SRK2000A device implements matched turn-off
MOSFET thresholds. A unique feature of this IC is
its intelligent automatic sleep mode. It allows the
detection of a low-power operating condition for
the converter and puts the IC into a low
consumption sleep mode where gate driving is
stopped and quiescent consumption is reduced.
In this way, converter efficiency improves at light
load, where synchronous rectification is no longer
beneficial. The IC automatically exits sleep mode
and restarts switching as it recognizes that the
load for the converter has increased.
A noticeable feature is the very low external
component count required.
Table 1. Device summary
Order code
Package
Packing
SRK2000A
SRK2000ATR
SO-8
Tube
Tape and reel
May 2017
This is information on a product in full production.
DocID025407 Rev 3
1/19
www.st.com