SRK2001A:Adaptive synchronous rectification controller for LLC resonant converter

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.

Key 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
  • VCC 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
Product Specifications
DescriptionVersionSize
DS11726: Adaptive synchronous rectification controller for LLC resonant converter1.0478 KB
Presentations
DescriptionVersionSize
Secondary regulation Synchronous rectification controllers2 MB
Brochures
DescriptionVersionSize
Brochure Power management guide05.20164 MB
Sample & Buy
Part NumberPackagePacking TypeUnit Price (US$) *QuantityECCN (EU)ECCN (US)Country of Origin
SRK2001ATRSSOP 10Tape And Reel0.751000NECEAR99MOROCCO
SRK2001ASSOP 10Tube0.751000NECEAR99-
Quality & Reliability
Part NumberPackageGradeRoHS Compliance GradeMaterial Declaration**
SRK2001ATRSSOP 10IndustrialEcopack2
SRK2001ASSOP 10IndustrialEcopack2
Adaptive synchronous rectification controller for LLC resonant converter SRK2001A
Secondary-side rectification for an LLC resonant converter featuring the SRK2000 SRK2000
Very low drop voltage regulators with inhibit KFXX