Monolithic Power Systems Inc. MP6920DN-LF-Z

Overview

MP6920DN-LF-Z from Monolithic Power Systems is a fast turn-off intelligent rectifier IC for flyback converters, integrating a 60V/10mΩ MOSFET to replace diode rectifiers. It regulates V_DS to ~70mV during conduction and actively turns off before reverse voltage develops, enabling up to 1.5W power savings in notebook adapters operating at ≤300kHz with 8–24V V_DD supply.

For engineers reviewing the MP6920DN-LF-Z datasheet, MP6920DN-LF-Z pinout, MP6920DN-LF-Z application, or MP6920DN-LF-Z equivalent, this device supports both high-side and low-side synchronous rectification in DCM and quasi-resonant flyback topologies while meeting Energy Star 1W standby requirements and delivering <300µA quiescent current in light-load mode.

Technical Context

The MP6920 implements adaptive gate control to regulate V_DS at −70mV during forward conduction using internal sense feedback from the SENSE pin (exposed pad), with blanking-integrated timing logic ensuring minimum on-time of 1.6µs and turn-off threshold at −30mV. Its control loop operates without external compensation.

It features dual-mode operation: normal synchronous rectification with 200ns turn-on/45ns turn-off delays, and light-load latch-off mode triggered when conduction time falls below 2.2µs-reducing driver loss via gate latching and re-enabling rectification only after body-diode conduction exceeds −250mV for >2.4µs.

Key Specifications

Pinout & Package

MP6920DN-LF-Z uses an SOIC-8E package with exposed thermal pad (VD) and 8-pin layout optimized for high-current secondary-side rectification. The exposed pad serves as the MOSFET drain terminal and primary thermal path.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar intelligent rectifier applications.

Compared with NCP4306DR2G and SiHP20N60E, MP6920DN-LF-Z delivers integrated control + power in one SOIC-8E package, enabling faster time-to-market for sub-60V flyback adapters needing <1W standby, while offering superior thermal performance via exposed-pad packaging and patented V_DS-regulated conduction.

Availability

MP6920DN-LF-Z is available at Aetrix Electronics and suitable for USB-C PD adapters, industrial flyback PSUs, and battery charger systems requiring stable component supply, RoHS-compliant packaging, and long-term lifecycle support.

Supply support for MP6920DN-LF-Z includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Monolithic Power Systems (MPS) is a fabless semiconductor company specializing in high-performance analog and power ICs, with design centers in the US, China, and Taiwan and global manufacturing partnerships.

The MP6920 belongs to MPS's intelligent rectifier product line, engineered specifically to replace Schottky diodes in flyback converters by integrating MOSFET and adaptive gate control-targeting efficiency-critical AC/DC adapters and industrial power supplies.

FAQ

What is the purpose of the SENSE pin on MP6920DN-LF-Z?

The SENSE pin connects directly to the exposed drain pad (VD) to provide real-time V_DS feedback for the internal regulation circuit. It enables precise −70mV conduction voltage control and accurate −30mV turn-off threshold detection, eliminating need for external sense resistors or op-amps.

Can MP6920DN-LF-Z operate in high-side rectifier configuration?

Yes-MP6920DN-LF-Z supports both high-side and low-side synchronous rectification. Its VSS pins serve as the MOSFET source reference, and the SENSE-to-VD sensing architecture allows direct integration into either topology without level-shifting circuitry.

How does the light-load latch-off function improve efficiency?

When conduction time drops below 2.2µs, the MP6920 latches its gate driver off after a 120µs delay, reducing gate charge loss. This cuts quiescent current to <300µA while allowing body-diode conduction until V_DS exceeds −250mV, then re-enables synchronous rectification-optimizing standby power.

What thermal considerations apply to the exposed pad (VD)?

VD is the MOSFET drain and primary thermal path. It requires a minimum 12mm² copper pour connected via ≥6 thermal vias (0.3mm diameter) to inner ground planes. Thermal resistance θ_JA is 50°C/W on a 4-layer board; exceeding 2.5W dissipation triggers thermal shutdown.

Is MP6920DN-LF-Z compatible with quasi-resonant (QR) flyback controllers?

Yes-the MP6920 is explicitly designed for QR and DCM flyback topologies. Its 200ns turn-on delay and 45ns turn-off delay align with QR valley-switching timing, and its blanking logic prevents false triggering during resonant ringing periods.

What is the significance of the −70mV V_DS regulation target?

The −70mV target balances conduction loss minimization against noise immunity. At typical 3–5A loads, it yields <0.4W dissipation versus >1.2W for a 40V/0.5V_F Schottky diode, while remaining above comparator noise floor to ensure stable regulation without oscillation.

Does MP6920DN-LF-Z require external bootstrap components?

No-MP6920DN-LF-Z uses self-biased gate drive powered from VDD. It contains no bootstrap capacitor or diode requirement, simplifying layout and eliminating failure modes associated with external bootstrap networks in high-side configurations.