Monolithic Power Systems Inc. MP6908LGJ-Z

Overview

MP6908LGJ-Z from Monolithic Power Systems is a fast turn-off intelligent rectifier IC designed to replace Schottky diodes in high-efficiency flyback converters. It regulates external SR MOSFET forward drop to ~40mV, achieves 25–45ns turn-off delay, supports 0V–150V VD operation, and enables self-powered operation without auxiliary winding in both high-side and low-side configurations-used in USB PD quick chargers and ultra-low-voltage adapters.

For engineers reviewing the MP6908LGJ-Z datasheet, MP6908LGJ-Z pinout, MP6908LGJ-Z application, or MP6908LGJ-Z equivalent, this page delivers verified functional identity, confirmed TSOT23-6 package mapping, validated 6-pin terminal roles, real-world DCM/CCM/quasi-resonant timing behavior, and precise gate-drive performance metrics for synchronous rectifier design validation.

Technical Context

The MP6908LGJ-Z implements adaptive gate control using voltage-sense (VD) and slew-rate detection (SLEW) to prevent false turn-on during DCM ringing or quasi-resonant transitions. Its control circuitry dynamically regulates VDS to ~40mV during conduction and triggers turn-off at -3mV with 25ns propagation delay.

VDD generation is dual-path: charged via HVC (70mA, regulated at VHVC−0.7V or clamped at 9V) or VD (40mA, regulated at 5V), enabling stable operation down to 0V output with no auxiliary winding. The IC operates across -40°C to +125°C junction temperature and supports logic-level and standard SR MOSFETs.

Key Specifications

Pinout & Package

MP6908LGJ-Z is housed in a space-saving TSOT23-6 package (JEDEC MO-193 AB), with 0.65mm pitch, 2.9mm × 1.6mm footprint, and exposed pad for thermal enhancement. Pin 1 is bottom-left when reading top marking left-to-right.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MP6908GJ-Z and SRK1001TR, MP6908LGJ-Z uniquely combines slew-rate–enabled false-turn-on immunity, dual-path VDD self-generation, and 40mV precision regulation-making it the only option qualified for high-density, no-auxiliary-winding USB PD and variable-output adapters demanding sub-30ns timing control.

Availability

MP6908LGJ-Z is available at Aetrix Electronics and suitable for USB PD quick chargers, universal flyback adapters, and low-voltage battery charging circuits requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for MP6908LGJ-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 intelligent power solutions.

The MP6908L product line targets high-efficiency AC/DC secondary-side synchronous rectification, specifically engineered to eliminate auxiliary windings, support zero-volt output, and deliver nanosecond-precision gate control in compact flyback systems.

FAQ

What is the function of the SLEW pin on MP6908LGJ-Z?

The SLEW pin configures the slew-rate detection timer (65–115ns) that prevents false turn-on caused by DCM or quasi-resonant ringing. An external resistor sets the blanking window: if VDS crosses the -86mV threshold slower than this time, the gate remains off-ensuring reliable operation without added RC filters.

Can MP6908LGJ-Z operate with 0V output voltage?

Yes. The IC draws power from VD when HVC is inactive, regulating VDD to 5V even at 0V output. Its -1V to +150V VD rating and absence of body-diode conduction enable true zero-volt operation-verified in USB PD and battery charging applications with short-circuit conditions.

How does MP6908LGJ-Z generate VDD in high-side rectification?

In high-side configuration, VDD is generated either by connecting HVC to VD (regulating VDD at 9V) or by routing HVC to secondary ground via an external diode (also 9V). When HVC falls below 4.7V, VD takes over and regulates VDD at 5V-enabling robust self-biasing without auxiliary winding in all operating modes.

What is the maximum recommended resistance between VD and MOSFET drain?

The datasheet specifies 300Ω to 1kΩ. Below 300Ω, overvoltage stress on VD increases during body-diode conduction; above 1kΩ, VDD charging slows and VDS slew rate degrades-compromising turn-on timing accuracy and regulation stability in high-frequency designs.

Does MP6908LGJ-Z support continuous conduction mode (CCM)?

Yes. Its adaptive gate control maintains ~40mV VDS regulation even at low currents, and its 15ns turn-off propagation delay ensures clean commutation in CCM. The IC explicitly lists CCM support in its operational modes and has been validated in 36W CCM flyback reference designs.

What is the purpose of the turn-on blanking time (t_B-ON)?

t_B-ON (1.1–2.1µs) prevents premature turn-off due to post-turn-on ringing. During this period, the gate remains latched on unless VDS rises above 2–3V-ensuring stable conduction through initial transient spikes while still allowing immediate shutdown if overvoltage occurs.

Is MP6908LGJ-Z RoHS and halogen-free compliant?

Yes. All MPS parts, including MP6908LGJ-Z, are lead-free, halogen-free, and fully compliant with the EU RoHS directive. Green status documentation and material declarations are available on the Monolithic Power Systems website under Quality Assurance.