Monolithic Power Systems Inc. MP6973GS-P

Overview

MP6973GS-P from Monolithic Power Systems is a CCM/DCM flyback synchronous rectifier IC integrating a 100V/14mΩ MOSFET, designed for low-side rectification in AC-DC adapters. It regulates forward voltage drop to 40mV, achieves 25ns turn-off delay, supports quasi-resonant operation, and delivers 110µA quiescent current - enabling high-efficiency USB PD and laptop charger designs.

For engineers reviewing the MP6973GS-P datasheet, MP6973GS-P pinout, MP6973GS-P application, or MP6973GS-P equivalent, key selection criteria include its slew-rate detection for false-turn-on prevention in DCM, integrated 100V MOSFET with 14mΩ R_DS(ON), SOIC-8 thermal performance (θ_JA = 67°C/W), and compatibility with Energy Star-compliant flyback topologies.

Technical Context

The MP6973GS-P implements adaptive gate control using dual-voltage sensing (SENSE and HVC pins) to autonomously regulate V_DS to ~40mV during conduction and trigger turn-off at –3mV with 25ns delay. Its internal ringing detection circuitry discriminates between true demagnetization zero-crossing and parasitic ringing by evaluating slew rate - preventing false turn-on in DCM and QR modes.

Power delivery is managed via dual-path VDD generation: SENSE charges VDD below 5V; above 5.7V, HVC takes over with clamping at 6.7V. The IC operates across –40°C to +125°C junction temperature, with UVLO thresholds at 4.2V (rising) and 4.0V (falling), ensuring robust startup and sleep-mode recovery.

Key Specifications

Pinout & Package

MP6973GS-P is housed in a standard SOIC-8 package (JEDEC MS-012, variation AA) with exposed pad not electrically connected. The package supports surface-mount assembly and provides adequate thermal dissipation for ≤3A output applications when implemented with ≥2 oz copper and thermal vias.

Key Features

Applications

Equivalent & Alternatives

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

Compared with NCP4306DR2G and SiHP12N50C, MP6973GS-P uniquely integrates 100V switching capability, active 40mV forward-drop regulation, and slew-rate detection - enabling single-chip, high-efficiency solutions for universal-input, multi-voltage USB PD and laptop adapters without external FET or timing tuning.

Availability

MP6973GS-P is available at Aetrix Electronics and suitable for laptop adapters, USB PD chargers, and high-efficiency flyback converters requiring stable component supply, RoHS-compliant packaging, and long-term industrial lifecycle support.

Supply support for MP6973GS-P 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 power management ICs, with design centers in the US, China, and Taiwan, and global manufacturing partnerships.

The MP6973 product line targets high-density, high-efficiency AC-DC conversion - specifically engineered to replace Schottky diodes in flyback topologies while maintaining robustness across CCM, DCM, and quasi-resonant modes.

FAQ

What is the maximum continuous output current supported by MP6973GS-P?

The MP6973GS-P is rated for 3A continuous output current in universal-input (90–265VAC) laptop adapter applications, based on thermal limits (T_J ≤ 125°C) and 1.8W maximum power dissipation in SOIC-8. At 100°C case temperature, derated current drops to 8.9A per absolute max ratings, but practical design limits remain at 3A for sustained reliability without heatsinking.

Does MP6973GS-P require an auxiliary winding for startup?

No. MP6973GS-P supports self-biased startup via the SENSE pin directly from the output rail, eliminating need for auxiliary winding. When output voltage exceeds VDD UVLO threshold (4.2V), SENSE initiates VDD charging; if HVC voltage rises above 5.7V, it seamlessly transitions to HVC-based VDD regulation - enabling single-rail biasing in low-component-count adapters.

How does slew-rate detection prevent false turn-on in DCM operation?

Slew-rate detection compares the falling edge dV/dt of V_DS against a 30ns threshold. During DCM ringing, parasitic oscillations exhibit slow dV/dt (< threshold), so even if V_DS crosses the –80mV turn-on threshold, the IC inhibits gate activation. Only primary-switch turn-off events produce fast dV/dt (> threshold), ensuring gate turn-on occurs exclusively at true zero-current crossings.

Can MP6973GS-P be used in high-side rectification configurations?

No. MP6973GS-P is explicitly optimized for low-side rectification, as confirmed by its functional block diagram, pin functions (VS referenced to output ground), and typical application circuits. High-side use would violate VS pin voltage constraints and disable proper VDD generation - MPS does not characterize or guarantee operation in high-side topology.

What is the recommended external resistor value between SENSE and VD?

A 100Ω–300Ω resistor is recommended between SENSE and VD to limit negative voltage stress on the SENSE pin during body-diode conduction. Values below 100Ω offer insufficient protection; values above 300Ω degrade V_DS slew-rate detection fidelity. For 36W QC adapters, 220Ω is commonly validated to balance protection and timing accuracy.

Is MP6973GS-P compatible with quasi-resonant (QR) controllers?

Yes. MP6973GS-P is explicitly qualified for QR operation, with internal ringing detection and turn-on blanking (1.2µs) that suppress false triggering during resonant valley switching. Its 25ns turn-off delay and –3mV turn-off threshold ensure precise deactivation at the optimal point in the QR waveform, preserving valley-switching efficiency gains.