Monolithic Power Systems Inc. MP86885GQWT-P

Overview

MP86885GQWT-P from Monolithic Power Systems is a monolithic half-bridge Intelli-Phase solution integrating high-side and low-side MOSFETs with gate driver, delivering 40A continuous output current, operating from 4.5V–14V input, supporting 100kHz–1MHz switching, and featuring integrated current sense (10μA/A) and temperature sense (10mV/°C) for server core voltage regulation.

For engineers reviewing the MP86885GQWT-P datasheet, MP86885GQWT-P pinout, MP86885GQWT-P application, or MP86885GQWT-P equivalent, this device requires attention to tri-state PWM interface compatibility, bootstrap capacitor selection (0.22–1μF), fault reporting via open-drain FAULT# pin, and thermal management in multi-phase VR12.5 systems using controllers like MP2935.

Technical Context

The MP86885GQWT-P implements a fully integrated half-bridge power stage with level-shifted high-side driver and adaptive dead-time control (3ns rising / 8ns falling), enabling precise synchronous buck operation without external gate drivers. It supports diode emulation mode via SYNC pin and provides cycle-by-cycle current monitoring through bi-directional CS output.

Its junction temperature sensing (VTEMP = 10mV/°C + offset) and over-temperature protection at 170°C enable real-time thermal coordination across multi-phase CPU/GPU VRs. The device interfaces directly with tri-state PWM controllers and reports faults including HS overcurrent (60A limit), VDD UVLO, and thermal shutdown - but not LS overcurrent (–25A limit).

Key Specifications

Pinout & Package

MP86885GQWT-P uses a 4mm × 6mm 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 contiguous ground array for low-inductance power return and thermal conduction.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar half-bridge Intelli-Phase applications.

Compared with MP86885GQWT-P, MP86905GQWT offers higher current capability and better thermal performance for long-term reliability, while MP86955GQWT adds digital telemetry and broader input support - both require PCB layout updates and controller firmware alignment.

Availability

MP86885GQWT-P is available at Aetrix Electronics and suitable for server CPU core regulators, GPU voltage regulation, and AI accelerator module power requiring stable component supply amid ongoing end-of-life transitions.

Supply support for MP86885GQWT-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 analog and power ICs for computing, cloud, automotive, and industrial markets.

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

FAQ

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

The datasheet specifies a 0.22μF to 1μF ceramic capacitor between BST and SW pins. A 0.47μF X7R 16V capacitor placed adjacent to the device is optimal for 600kHz operation, ensuring sufficient gate drive voltage margin while minimizing ringing. Capacitance below 100nF is prohibited.

Does MP86885GQWT-P support diode emulation mode, and how is it activated?

Yes - pulling the SYNC pin low enables diode emulation mode, which turns off the low-side FET after inductor current crosses zero. This reduces light-load conduction losses and improves efficiency below ~20% load. The pin must be actively driven low; leaving it open or pulled high disables the feature.

How is current sense gain calibrated, and what external components are required?

Current sense gain is fixed at 10μA/A. Calibration is achieved by selecting RIN (pin 9 to IN) to set gain scaling: RIN = 7.55kΩ − 170×IL_RIPPLE. For 10A ripple, use 95.3kΩ (1%). An external RCS resistor from CS to VOUT (or reference) sets common-mode voltage between 1V–3.5V for linear operation.

Why does the FAULT# pin not assert during low-side overcurrent events?

The FAULT# pin is designed to report only high-side overcurrent (≥60A), VDD UVLO, or overtemperature (>170°C). Low-side overcurrent (≤–25A) triggers internal cycle-by-cycle blanking but does not pull FAULT# low - this allows continued operation during brief reverse-current transients without system-level fault escalation.

Can MP86885GQWT-P be used in single-phase applications, or is it limited to multi-phase?

It is fully functional in single-phase buck converters, but its design emphasis is multi-phase operation: the tri-state PWM interface, per-phase VTEMP/CS outputs, and paralleled SW pins are optimized for synchronization and current balancing across ≥2 phases. Single-phase use is valid but underutilizes key features.

What is the maximum allowable continuous power dissipation at 25°C ambient?

At TA = +25°C, the maximum continuous power dissipation is 3.5W, calculated from θJA = 36°C/W and TJ(MAX) = 150°C. Exceeding this causes thermal shutdown. Layout with 4-layer PCB, full thermal pad soldering, and 6+ vias to inner ground planes is required to sustain rated 40A output.

Is MP86885GQWT-P RoHS-compliant and lead-free?

Yes - MP86885GQWT-P is RoHS 6-compliant and lead-free per MPS quality standards. All packaging materials meet JEDEC J-STD-020 moisture sensitivity level 3 (MSL3) requirements, and the FC-TQFN package uses matte tin finish on exposed copper leads.