Monolithic Power Systems Inc. MP86905GR-Z

Overview

MP86905GR-Z from Monolithic Power Systems is a monolithic half-bridge power stage IC integrating high-side and low-side MOSFETs, gate drivers, current sensing (Accu-Sense™), and junction temperature sensing. It delivers 50A continuous output current, operates from 4.5V to 16V input, supports 100kHz–2MHz switching, and features tri-state PWM acceptance and fault reporting via open-drain FAULT#. It is deployed in multi-phase buck regulators for server core voltage regulation.

For engineers reviewing the MP86905GR-Z datasheet, MP86905GR-Z pinout, MP86905GR-Z application, or MP86905GR-Z equivalent, key selection criteria include its integrated current/temperature sensing accuracy, 50A continuous rating with 90A peak capability, 3ns–35ns programmable dead time, FC-QFN-23 (4mm×4mm) thermal performance (θJB = 2°C/W), and compatibility with tri-state PWM controllers in high-density VRM designs.

Technical Context

The MP86905 implements a fully integrated half-bridge topology with level-shifted high-side driver, zero-current detection (ZCD) for diode emulation, and cycle-by-cycle high-side current limiting with four-cycle latch-off. Its Accu-Sense™ current sense provides ±2% gain accuracy over 15–50A output range and linear 0.7–2.1V CS output voltage.

Thermal management is enabled by an analog VTEMP output (10mV/°C, −100mV offset) reporting junction temperature, with over-temperature shutdown at 160°C and 30°C hysteresis. Fault reporting integrates SW-to-PGND short detection, HS current limit, and OTP into a single open-drain FAULT# signal.

Key Specifications

Pinout & Package

MP86905GR-Z is housed in a thermally enhanced FC-QFN-23 package (4mm × 4mm, 0.5mm pitch) with exposed thermal pad. The package supports high-current routing via 11 PGND pins and optimized thermal conduction to PCB ground plane.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TDA21472 and NCP302155, MP86905GR-Z uniquely combines 50A capability with integrated Accu-Sense™ current sensing, analog VTEMP telemetry, tri-state PWM acceptance, and diode emulation-enabling higher integration, tighter thermal control, and simplified controller interface in next-gen server and AI power systems.

Availability

MP86905GR-Z is available at Aetrix Electronics and suitable for server core voltage regulation, GPU power delivery, AI accelerator modules, and telecom VRMs requiring stable component supply, long-term lifecycle support, and traceable sourcing.

Supply support for MP86905GR-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 MP86905 belongs to MPS's Intelli-Phase™ family of integrated power stages, designed specifically for high-current, high-efficiency, multi-phase buck converters in datacenter and AI infrastructure where power density, thermal visibility, and digital control interoperability are critical.

FAQ

What is the maximum peak current the MP86905GR-Z can handle?

The MP86905GR-Z supports 90A instantaneous current per the Absolute Maximum Ratings table. This is a non-repetitive, short-duration rating (25ns pulse width) validated under worst-case thermal conditions. Continuous operation remains limited to 50A with proper PCB thermal design and airflow.

Does MP86905GR-Z require an external bootstrap diode?

No. The MP86905GR-Z integrates an internal bootstrap diode and requires only an external BST capacitor (0.1–1µF, 0402 size) between BST and SW pins. This eliminates external diode placement and associated parasitics, simplifying layout and improving reliability.

How does the tri-state PWM function enable diode emulation?

When PWM voltage resides in the 1.10–1.90V window for ≥50ns, the MP86905GR-Z immediately turns off the HS-FET and activates LS-FET conduction until zero-current detection occurs. This mimics synchronous rectifier behavior without requiring external ZCD circuitry or controller firmware changes.

Can MP86905GR-Z operate without a VDRV supply?

No. VDRV (3.0–3.6V) is mandatory to power the gate drivers. The datasheet specifies that operation begins only after both VDD and VDRV exceed their respective UVLO thresholds (2.9V and 2.9V). Omitting VDRV prevents HS/LS FET switching and may cause undefined behavior.

What is the recommended PCB layout practice for thermal management?

Use ≥11 thermal vias under the exposed paddle, connect them to an inner-layer PGND plane, and place ≥8 PGND vias adjacent to PGND pins 5–13. Maintain ≥20-mil trace width for VIN/PGND paths and locate input MLCCs within 2mm of VIN/PGND pins to achieve θJB = 2°C/W.

Is the CS output compatible with standard ADC inputs?

Yes. The CS pin outputs a 9.7µA/A current source with linear 0.7–2.1V compliance range. When terminated with a precision resistor (e.g., 100Ω), it generates 0.97–2.1V analog voltage directly compatible with 12-bit+ SAR ADCs found in common PMBus controllers.

How is the FAULT# signal reset after latching?

A latched FAULT# (due to HS over-current or OTP) is cleared only by cycling power on VIN or VDD/VDRV, or by toggling the EN pin low then high. Simply clearing the fault condition (e.g., cooling down) does not auto-reset the latch-ensuring persistent fault indication until deliberate recovery action.