Monolithic Power Systems Inc. MP6908AGJ-Z

Overview

MP6908AGJ-Z from Monolithic Power Systems is a fast turn-off intelligent rectifier controller IC designed for synchronous rectification in flyback converters. It replaces Schottky diodes by driving an external MOSFET with programmable slew-rate detection, 40mV forward-drop regulation, ~30ns turn-off delay, and support for DCM/CCM/quasi-resonant operation - enabling high-efficiency USB PD quick chargers and low-voltage adaptors.

For engineers reviewing the MP6908AGJ-Z datasheet, MP6908AGJ-Z pinout, MP6908AGJ-Z application, or MP6908AGJ-Z equivalent, key selection criteria include its no-auxiliary-winding capability for high-side/low-side SR, VD sensing-based zero-current detection, 100µA quiescent current, and TSOT23-6 package compatibility with compact power designs.

Technical Context

The MP6908AGJ-Z implements adaptive gate control using VD (drain voltage) sensing to regulate MOSFET conduction at ~40mV forward drop and trigger turn-off when VDS crosses –3mV. Its internal linear regulator generates VDD from either HVC or VD, supporting self-powered operation down to 0V output without auxiliary winding.

Programmable slew-rate detection on the SLEW pin prevents false turn-on during DCM/quasi-resonant ringing, while turn-on blanking (~450ns) and turn-off blanking (VDS > 2V release) ensure robust timing control. The IC operates across –40°C to +125°C junction temperature with UVLO (3.55V–3.95V) and thermal shutdown protection.

Key Specifications

Pinout & Package

MP6908AGJ-Z is housed in a thermally enhanced TSOT23-6 package (2.9mm × 1.6mm × 0.9mm), optimized for high-density flyback secondary-side placement with low θJA (220°C/W).

Key Features

Applications

Equivalent & Alternatives

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

Compared with MP6908GJ-Z and SRK1001TR, MP6908AGJ-Z delivers superior high-frequency stability via programmable slew-rate detection, enables true 0V-capable self-supply, and achieves 2.5× lower quiescent current - making it optimal for next-gen compact, multi-protocol USB PD chargers.

Availability

MP6908AGJ-Z is available at Aetrix Electronics and suitable for USB PD quick chargers, universal-input adaptors, and flyback power supplies requiring stable component supply, long-term lifecycle continuity, and RoHS-compliant packaging.

Supply support for MP6908AGJ-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 power management ICs, with over two decades of expertise in DC/DC conversion, motor drivers, and power modules.

The MP6908A belongs to MPS's intelligent rectifier controller product line, engineered specifically for high-efficiency, auxiliary-winding-free synchronous rectification in flyback converters targeting USB PD, computing, and industrial power applications.

FAQ

What is the purpose of the SLEW pin on MP6908AGJ-Z?

The SLEW pin accepts an external resistor to program a turn-on timer (65–115ns) that rejects false triggering from VDS ringing during DCM or quasi-resonant operation. When the slew rate of VDS crossing the –86mV threshold falls below the programmed value, the IC suppresses gate turn-on - preventing shoot-through and improving reliability in high-frequency flyback designs.

Can MP6908AGJ-Z operate with 0V output voltage?

Yes. MP6908AGJ-Z supports true 0V output operation in low-side configurations by generating VDD directly from VD, even during short-circuit conditions. Its VD sensing architecture and –3mV turn-off threshold ensure stable zero-current detection without auxiliary winding or external bias, meeting requirements for USB PD PPS and lab-grade variable supplies.

How does MP6908AGJ-Z generate its VDD supply in high-side rectification?

In high-side configurations, MP6908AGJ-Z generates VDD via three validated methods: (1) HVC tied to VD (regulates VDD at 9V), (2) HVC tied to secondary ground through an external diode (also 9V), or (3) HVC shorted to VSS (regulates VDD at 5V from VDS). All methods eliminate need for auxiliary winding and support operation across full input voltage range.

What is the maximum recommended external resistor between VD and MOSFET drain?

The datasheet recommends limiting the external resistor between VD and MOSFET drain to ≤1kΩ. A larger value degrades VDD supply stability and slows VDS slew rate, risking missed turn-off events. For most designs, 300Ω–680Ω provides optimal trade-off between overvoltage protection and sensing fidelity - verified in 36W flyback reference designs.

Does MP6908AGJ-Z support both standard and logic-level MOSFETs?

Yes. Its VG output delivers 4.9V high-level drive and sinks 3A, ensuring full enhancement of logic-level MOSFETs (VGS(th) ≤ 2.5V) and standard MOSFETs (VGS(th) ≤ 4V). The 20mV low-level output guarantees rapid turn-off, and the 40mV forward-drop regulation decouples conduction loss from RDS(ON), simplifying MOSFET selection.

What is the thermal shutdown behavior of MP6908AGJ-Z?

MP6908AGJ-Z incorporates internal thermal shutdown that activates at 150°C junction temperature. Upon triggering, the IC disables VG output and enters sleep mode until junction temperature drops below 125°C hysteresis threshold. This protects the device during sustained overload or poor PCB thermal design while maintaining safe operation per JEDEC JESD51-7 thermal testing standards.