STMicroelectronics SRK2000D

Overview

SRK2000D from STMicroelectronics is a synchronous rectifier smart driver designed for LLC resonant converter secondary-side rectification. It drives two external N-channel MOSFETs in center-tapped secondary winding architectures, replacing conventional diode rectification to reduce conduction loss and improve power conversion efficiency in high-current isolated AC-DC power supplies.

For engineers reviewing the SRK2000D datasheet, SRK2000D pinout, SRK2000D application, or SRK2000D equivalent, this device is most relevant for LLC converter synchronous rectification, server SMPS, ATX power supplies, industrial power supplies, high-power adapters, and compact AC-DC designs requiring dual gate outputs, current reversal protection, automatic sleep mode, programmable UVLO, and SO-8 assembly.

Technical Context

SRK2000D senses the drain-source behavior of the secondary-side MOSFETs and controls their gate drive timing so that each MOSFET conducts during the correct portion of the LLC secondary waveform. This reduces the voltage drop normally associated with rectifier diodes, which is especially valuable in low-voltage, high-current outputs where diode conduction loss can dominate thermal performance.

The device includes interlock protection to prevent both synchronous rectifier MOSFETs from conducting at the same time. It also uses current reversal protection and automatic sleep behavior, helping the rectifier stage remain stable during startup, load transients, and light-load operation. Proper drain-sense routing, SGND / PGND handling, and MOSFET selection remain important because secondary-side switching noise directly affects turn-off timing and safe conduction margin.

Key Specifications

Pinout & Package

SRK2000D is supplied in an SO-8 package with separate signal ground and power ground references. The pin structure supports enable / threshold selection, two drain-sense inputs, two gate-drive outputs, and the VCC supply pin required for secondary-side synchronous rectifier control.

Key Features

• Dual synchronous rectifier driver for LLC resonant converters with center-tapped secondary windings.
• Controls two external N-channel MOSFETs for full-wave secondary-side rectification.
• 1 A source and 3.5 A sink gate-drive capability for fast and controlled MOSFET switching.
• 4.5 V to 32 V VCC operating range for common secondary auxiliary supplies.
• Interlock protection helps prevent simultaneous conduction of both rectifier MOSFETs.
• Current reversal protection reduces reverse-current stress near zero-current crossing.
• Programmable undervoltage lockout supports controlled startup and supply supervision.
• Automatic sleep mode improves behavior at light load and standby conditions.
• SO-8 package supports compact isolated power-supply secondary layouts.

Applications

Equivalent & Alternatives

When evaluating SRK2000D equivalent devices, engineers should compare converter topology, package, gate-drive current, VCC range, turn-off delay, sleep behavior, sensing method, MOSFET timing strategy, and whether the PCB layout and transformer secondary architecture match the controller requirements.

SRK2000D replacement selection should consider electrical behavior and PCB layout together. Even when another controller targets the same LLC synchronous rectification function, gate-drive strength, turn-off timing, package footprint, ground routing, and drain-sense implementation must match the power stage requirements.

Quality

SRK2000D should be sourced as original STMicroelectronics components through traceable and controlled supply channels. Quality verification procedures may include SO-8 package inspection, top-mark review, moisture and packing label inspection, lead coplanarity checks, solderability testing, VCC current screening, gate-output functional testing, EN threshold inspection, drain-sense continuity checks, and incoming inspection suited to power-management IC production requirements.

Availability

SRK2000D is available at Aetrix Electronics and suitable for LLC resonant AC-DC power supplies, server SMPS, ATX power supplies, high-power adapters, all-in-one PC power systems, industrial SMPS, and secondary-side synchronous rectifier assemblies requiring stable sourcing and repeatable production support.

Supply support may include scheduled delivery planning, volume procurement support, BOM continuity assistance, traceable sourcing management, and lifecycle availability coordination for power-supply manufacturers, industrial equipment builders, repair groups, contract manufacturers, and legacy LLC converter platforms.

For production deployment, confirming the SO-8 footprint, VCC supply range, MOSFET gate-charge requirement, center-tapped secondary topology, drain-sense routing, SGND / PGND layout, EN configuration, thermal margin, switching frequency, and sourcing continuity helps reduce procurement risk and improve manufacturing stability.

Manufacturer

STMicroelectronics supplies power-management ICs, microcontrollers, analog devices, sensors, protection components, memories, RF products, and discrete semiconductors for industrial, consumer, automotive, communication, and embedded applications. SRK2000D belongs to ST's synchronous rectifier controller portfolio for improving efficiency in LLC resonant converter secondary-side rectification.

FAQ

What is SRK2000D used for?

SRK2000D is used to drive external N-channel MOSFETs in LLC resonant converter secondary-side synchronous rectification. It is mainly used in center-tapped transformer secondary designs where replacing rectifier diodes with controlled MOSFETs reduces conduction loss, lowers heat, and improves efficiency in high-current AC-DC power supplies.

What topology does SRK2000D support?

SRK2000D supports LLC resonant converters with a center-tapped secondary winding and full-wave rectification. The device controls two synchronous rectifier MOSFETs, one for each secondary conduction interval, while its interlock behavior helps prevent both MOSFETs from being driven on at the same time.

What gate-drive capability does SRK2000D provide?

SRK2000D provides dual gate-drive outputs with 1 A source and 3.5 A sink capability. The strong sink current helps pull MOSFET gates down quickly during turn-off, which is important near current reversal and zero-current crossing in LLC synchronous rectifier operation.

What package is used by SRK2000D?

SRK2000D is supplied in an SO-8 surface-mount package. The package includes SGND, EN, two drain-sense inputs, two gate-drive outputs, PGND, and VCC. This pin arrangement supports compact secondary-side placement close to the synchronous rectifier MOSFETs and related sensing traces.

How does SRK2000D improve power-supply efficiency?

SRK2000D improves efficiency by controlling MOSFETs as synchronous rectifiers instead of relying on diode conduction. In low-voltage, high-current outputs, MOSFET on-resistance can produce much lower conduction loss than rectifier diode forward voltage, reducing secondary heat and improving total converter efficiency.

What should be checked before replacing SRK2000D?

Before replacing SRK2000D, check the SO-8 footprint, pinout, VCC rail, gate-drive current needs, drain-sense routing, EN threshold configuration, LLC secondary topology, switching frequency, and protection behavior. A similar synchronous rectifier controller may still require layout or qualification changes.