Monolithic Power Systems Inc. MP86885GQWT-Z

Overview

MP86885GQWT-Z from Monolithic Power Systems is a monolithic half-bridge Intelli-Phase solution integrating high-side and low-side power MOSFETs with gate drivers in a 4×6 mm FC-TQFN-29 package. It delivers 40 A continuous output current, supports 100 kHz–1 MHz switching, and features integrated current sense (10 μA/A), temperature sense (10 mV/°C), and tri-state PWM compatibility - optimized for server core voltage regulation.

For engineers reviewing the MP86885GQWT-Z datasheet, MP86885GQWT-Z pinout, MP86885GQWT-Z application, or MP86885GQWT-Z equivalent, key selection criteria include its 4.5–14 V input range, 3–8 ns dead-time control, fault reporting via open-drain FAULT# pin, and multi-phase synchronization capability with SYNC pin diode-emulation mode.

Technical Context

The MP86885 operates as a self-contained half-bridge power stage with integrated level-shifted gate drivers, enabling precise timing control between HS and LS FETs. Its internal bootstrap circuit eliminates external high-side driver complexity, while tri-state PWM acceptance allows seamless interface with VR12.5/VR13 controllers like MP2935.

Current sensing is implemented via a bi-directional CS pin with 10 μA/A gain and linear 1–3.5 V common-mode range, supporting cycle-by-cycle overcurrent protection and phase balancing. Junction temperature is monitored through VTEMP (10 mV/°C, ±5°C accuracy), with overtemperature shutdown at 170°C and thermal reporting to system controllers.

Key Specifications

Pinout & Package

MP86885GQWT-Z uses a 4 mm × 6 mm FC-TQFN-29 package with exposed thermal pad (JEDEC MO-220 compliant). Pin 1 is marked by index area; PGND pins (17–28) form a low-inductance ground plane; SW pins (12–15) are paralleled for current sharing.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar half-bridge power stage applications.

Compared with MP86885GQWT-Z, MP86905 offers higher current capability and better thermal performance for future-proof designs, while ISL99390 trades telemetry integration for smaller size - making MP86885 the optimal balance of intelligence, density, and maturity for existing server VRM upgrades.

Availability

MP86885GQWT-Z is available at Aetrix Electronics and suitable for server core voltage regulation, GPU power delivery, AI accelerator modules, and high-performance workstation VRMs requiring stable component supply and long-term lifecycle support.

Supply support for MP86885GQWT-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 mixed-signal ICs for power management, motion control, and automotive applications.

The MP86885 belongs to MPS's Intelli-Phase product line - engineered specifically for high-current, high-efficiency multi-phase buck converters in datacenter and computing infrastructure.

FAQ

What is the recommended bootstrap capacitor value for MP86885GQWT-Z?

The datasheet specifies a 0.22 µF to 1 µF ceramic capacitor between BST and SW pins. A 0.47 µF X7R 16 V capacitor placed adjacent to the device ensures reliable high-side gate drive across 100 kHz–1 MHz operation and minimizes voltage droop during peak current transitions.

Can MP86885GQWT-Z operate without an external current sense resistor?

No - the CS pin requires an external resistor (RCS) connected to VOUT or a reference voltage to establish proper bias and linear output range (1–3.5 V). Without RCS, the CS output cannot sink current, resulting in invalid current reporting and potential OCP failure.

How does the SYNC pin enable diode emulation mode?

Pulling SYNC low disables the low-side FET after inductor current crosses zero, allowing body-diode conduction only during reverse recovery. This reduces light-load conduction loss by eliminating synchronous rectification overhead - verified to improve efficiency by 3–5% at 5% load in server applications.

Is MP86885GQWT-Z pin-compatible with MP86905GQWT-Z?

Yes - both use identical FC-TQFN-29 (4×6 mm) packages and share identical pin functions, layouts, and PCB footprints. Migration requires only firmware validation and minor loop compensation tuning due to MP86905's lower R_DS(on) and higher current capability.

What thermal derating applies above 85°C ambient?

With θ_JA = 36°C/W on a 4-layer board, maximum continuous current must be reduced by ~0.35 A/°C above 85°C ambient to maintain T_J ≤ 125°C. At 100°C ambient, derated output is ~35 A; forced airflow or copper pour expansion restores full 40 A capability.

Does the FAULT# pin report low-side overcurrent events?

No - FAULT# asserts only for high-side overcurrent (60 A threshold), VDD under-voltage lockout, or junction temperature exceeding 170°C. Low-side overcurrent (−25 A) triggers cycle-by-cycle blanking but does not activate FAULT#, as specified in the Electrical Characteristics table.

How is junction temperature calculated from VTEMP voltage?

Using V_TEMP = 100 mV + (T_J × 10 mV/°C), valid for T_J > 10°C. For example, 700 mV on VTEMP corresponds to T_J = 80°C. Below 10°C, VTEMP reads 0 V due to internal clamping - measurement must be taken between VTEMP and AGND for accuracy.