Monolithic Power Systems Inc. MP6920DN-LF

Overview

MP6920DN-LF 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 turns off before voltage reversal, 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 datasheet, MP6920DN-LF pinout, MP6920DN-LF application, or MP6920DN-LF equivalent, key selection criteria include its 70mV V_DS regulation accuracy, 30ns turn-off delay, light-load mode (<300µA quiescent current), high-side/low-side rectification support, and SOIC8E exposed-pad thermal performance.

Technical Context

The MP6920 operates in DCM and quasi-resonant flyback topologies using internal control logic that senses V_DS across the integrated MOSFET to regulate forward drop and trigger precise turn-off at −30mV threshold. Its blanking circuit enforces 1.6µs minimum on-time and modifies turn-off sensitivity during startup to prevent false triggering.

It implements a latched light-load mode activated when conduction time falls below 2.2µs per cycle, reducing gate drive loss with 120µs entry delay and exit triggered by body-diode conduction exceeding −250mV for >2.4µs-enabling <300µA quiescent current while maintaining synchronous rectification integrity.

Key Specifications

Pinout & Package

MP6920DN-LF uses an SOIC8E package with exposed thermal pad (VD) and three V_SS pins for low-inductance source return. The 8-pin layout supports high-current synchronous rectification with dedicated SENSE pin for accurate V_DS monitoring.

Key Features

Applications

Equivalent & Alternatives

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

Compared with NCP4307DR2G and SiHP22N60E, MP6920DN-LF uniquely combines 70mV regulation accuracy, 30ns turn-off, and latched light-load mode in a single SOIC8E package-delivering measurable efficiency gains in 36W–65W QR flyback systems without controller redesign.

Availability

MP6920DN-LF is available at Aetrix Electronics and suitable for USB-C notebook adapters, industrial 24V flyback PSUs, and battery charger reference designs requiring stable component supply and long-term lifecycle support.

Supply support for MP6920DN-LF 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.

The MP6920 belongs to MPS's intelligent rectifier product line, engineered specifically to replace Schottky diodes in AC/DC flyback converters while meeting global energy efficiency standards.

FAQ

What is the maximum recommended PCB copper area for the exposed V_D pad?

The exposed pad (VD) must connect to a minimum 100mm² copper pour on the top layer, thermally vias (≥6×0.3mm) to inner ground planes, and no solder mask over the pad. This achieves the specified 50°C/W θ_JA and prevents junction temperature exceedance above 125°C at full load.

Does MP6920DN-LF support primary-side sensing flyback architectures?

No. MP6920DN-LF is strictly a secondary-side synchronous rectifier IC requiring direct V_DS sensing across its integrated MOSFET. It does not interface with primary-side controllers or support optocoupler-free regulation schemes.

Can SENSE pin be routed away from the exposed pad?

No. The SENSE pin must be shorted directly to the exposed V_D pad using a dedicated low-inductance trace (<2mm length, ≥0.3mm width). Any separation introduces measurement error and causes premature or delayed turn-off, risking shoot-through or reverse conduction.

What failure modes occur if V_DD drops below 5.0V UVLO threshold?

Below 5.0V, the IC enters sleep mode: the internal MOSFET remains off, gate driver disables, and quiescent current drops to <10µA. Recovery requires V_DD to rise above 7.0V (UVLO hysteresis) before normal operation resumes-preventing erratic switching during brown-out conditions.

Is MP6920DN-LF qualified for automotive AEC-Q100?

No. MP6920DN-LF is rated for industrial temperature range (−40°C to +125°C junction) but lacks AEC-Q100 qualification, stress testing, or automotive-specific documentation. It is intended for commercial/industrial power supplies, not automotive ECUs or infotainment systems.

How does the 1.6µs minimum on-time affect operation at 250kHz?

At 250kHz (4µs period), the 1.6µs minimum on-time consumes 40% of the switching cycle. This limits usable duty cycle range but ensures reliable turn-on in DCM operation where current zero-crossing detection is critical for synchronous timing accuracy.

What is the purpose of the −50mV modified turn-off threshold during blanking?

During the 1.6µs turn-on blanking period, the turn-off threshold shifts from −30mV to −50mV to prevent false triggering from noise or ringing immediately after turn-on. This allows stable conduction initiation while retaining ability to shut down if V_DS rises abnormally-ensuring robust fault tolerance.