This document describes the application of SRK2000 in LLC resonant converters with synchronous rectification (SR). It first introduces the features of the IC, followed by a description of the board, and finally provides some considerations regarding circuit optimization and performance. The board is realized in four different configurations depending on the mounted SR MOSFETs.
The document introduces the SRK2000 integrated circuit, which implements a control scheme for secondary-side synchronous rectification in LLC resonant converters with center-tap secondary windings. It details the IC's main characteristics, including drain MOSFET sensing and driving logic, optimization of drain sensing, blanking time settings, and light load operation modes.
The text also covers the EVLSRK2000 family of demonstration boards, which are available in four different configurations based on the mounted SR MOSFETs. The guide provides instructions on how to implement the board in a converter, discusses power losses and thermal design considerations, and offers layout guidelines for optimizing circuit performance.
| Gate-drive outputs | two high-current |
|---|---|
| Interlocking logic | prevents simultaneous conduction |
| Clamping circuit rating | 36 V typ. |
| Maximum injected current | 25 mA |
| DVS pin current | 50 µA typ. |
| DVS pin clamp voltage | -0.2 V typ. |
| DVS pin capacitance | about 10 pF |
It switches on each synchronous rectifier MOSFET when the transformer half-winding starts conducting and switches it off when the current approaches zero.
The boards are realized in four different configurations depending on the mounted SR MOSFETs.
The blanking time is introduced to avoid false triggering of the gate driver after the current generator is activated.