Monolithic Power Systems Inc. EV8859-Q-00B

Overview

EV8859-Q-00B from Monolithic Power Systems is an evaluation board for the MP8859 synchronous 4-switch integrated buck-boost converter IC, designed to validate USB PD sourcing port implementations. It supports 2.8V–22V input, delivers up to 3A output at 5V (adjustable to 20.47V via I²C), operates at 500kHz, and features programmable CC current limit, hiccup-mode OVP/SCP, and thermal shutdown.

For engineers reviewing the EV8859-Q-00B datasheet, EV8859-Q-00B pinout, EV8859-Q-00B application, or EV8859-Q-00B equivalent, this board enables rapid validation of I²C-configurable buck-boost regulation, load transient response under forced PWM mode, and OTP-programmed startup behavior in USB PD and bus supply designs.

Technical Context

The EV8859-Q-00B implements the MP8859GQ-0000 QFN-16 (3mm×3mm) IC with constant-on-time control in buck mode and constant-off-time control in boost mode, enabling seamless mode transition and fast load transients. It integrates internal sensing FETs for accurate CC current limiting and supports four I²C addresses (ALT pin selectable).

OTP-efuse configuration sets default VOUT=5V, IOUT_LIMIT=3.5A, soft-start=900μs, line-drop compensation=150mV@3A, and forced PWM mode. The board includes full protection: hiccup-mode OVP, SCP, UVP, and thermal warning/shutdown with discharge-enabled output voltage discharge.

Key Specifications

Availability

EV8859-Q-00B is available at Aetrix Electronics and suitable for USB PD sourcing port development, buck-boost bus supply validation, and I²C-programmable power architecture prototyping requiring stable component supply and traceable evaluation hardware.

Supply support for EV8859-Q-00B 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, with design centers across Asia and North America and global distribution.

The MP8859 product line targets USB Power Delivery and adaptive bus supply applications, delivering integrated 4-switch buck-boost conversion with digital configurability, robust protection, and small-footprint QFN packaging.

FAQ

What is the primary function of the EV8859-Q-00B?

The EV8859-Q-00B is a fully assembled evaluation board for the MP8859 4-switch buck-boost converter IC. Its purpose is to accelerate design-in of USB PD sourcing ports and adjustable bus supplies by providing validated schematics, layout, BOM, test waveforms, and I²C programming examples - not a production-ready power module.

Does the board support both buck and boost modes automatically?

Yes. The underlying MP8859 IC uses constant-on-time control in buck mode and constant-off-time control in boost mode, enabling automatic, seamless transitions between modes across the full 2.8V–22V input range while maintaining regulated output voltage - demonstrated in load transient and start-up waveforms on pages 4–7 of the reference document.

How is output voltage programmed on this board?

Voltage is set digitally via I²C interface with 10mV resolution over a 1V–20.47V range. Default is 5V, stored in OTP efuse. The board includes SCL/SDA headers and ALT pin for address selection, and all register maps and command sequences are defined in the MP8859 datasheet (Rev. 1.0, p.12–15).

What protections are implemented and how do they behave?

The board implements hiccup-mode OVP and short-circuit protection, thermal shutdown with warning flag, UVP, and programmable CC current limiting. During overvoltage or short circuit, the device cycles on/off until fault clears - confirmed by SCP entry/recovery waveforms on page 7 showing 10ms hiccup intervals.

Is the MP8859 IC soldered to the board, and what package does it use?

Yes - the MP8859GQ-0000 IC is mounted in a 16-pin QFN package (3mm×3mm, 0.5mm pitch) as specified in the Bill of Materials (page 3). The footprint matches MPS's recommended layout, and thermal pads are exposed on the bottom layer per standard QFN assembly guidelines.

Can the board be used for production power delivery?

No. The EV8859-Q-00B is strictly an evaluation platform - it lacks safety certifications (UL/IEC), has no input/output filtering for conducted EMI compliance, and uses generic passives not qualified for long-term field reliability. It serves only for functional validation and parameter tuning prior to custom design.