Monolithic Power Systems Inc. EVM3690-20B-BF-00A

Overview

EVM3690-20B-BF-00A from Monolithic Power Systems is a fully assembled evaluation board for the MPM3690-20B synchronous step-down power module, delivering up to 26A at 1.2V output from a 3.2–16V input. It integrates dual 22μF ceramic output capacitors per phase, fSET resistor network for 400kHz–1MHz frequency selection, and PMBus-compatible control interface. Designed for rapid validation of high-current point-of-load regulation in server CPU/GPU VR applications.

For engineers reviewing the EVM3690-20B-BF-00A datasheet, EVM3690-20B-BF-00A pinout, EVM3690-20B-BF-00A application, or EVM3690-20B-BF-00A equivalent, this board enables direct measurement of efficiency (92.5% @12V_IN/1.2V_OUT/26A), load transient response (0→13A @10A/μs), thermal performance (T_CASE = 57.6°C @26A, no airflow), and startup/shutdown sequencing via EN or VIN.

Technical Context

The EVM3690-20B-BF-00A implements the MPM3690-20B's internally compensated constant-on-time (COT) control architecture, enabling fast transient response without external loop compensation. It supports dual-phase operation with interleaved switching to reduce input/output ripple and improve thermal distribution across the 16mm × 16mm BGA module.

Board-level features include dedicated VOUT sense points (VOSENSE/VOGNDSEN), programmable MODE/PMODE pins for light-load efficiency optimization, RAMP1/RAMP2 test points for slope compensation verification, and a 10-pin PMBus connector for real-time telemetry (voltage, current, temperature, fault status) and configuration.

Key Specifications

Availability

EVM3690-20B-BF-00A is available at Aetrix Electronics and suitable for high-current DC/DC validation, server VRM prototyping, and AI accelerator power subsystem testing requiring stable component supply and documented thermal/measurement reference data.

Supply support for EVM3690-20B-BF-00A 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 and modules, with design centers in the US, China, and Taiwan, and global manufacturing partnerships.

The EVM3690-20B-BF-00A belongs to MPS's high-current integrated power module evaluation platform family, engineered specifically to accelerate adoption of their MPM3690 series in demanding compute and infrastructure applications where compact size, thermal robustness, and digital configurability are critical.

FAQ

What input voltage range is supported, and what happens below 4V?

The board accepts 3.2V to 16V input. When VIN drops below 4V, the internal bias rail cannot be sustained, requiring an external 3.3V supply connected to the VCC pin-this is explicitly noted in the quick start guide and verified in the schematic's VCC routing and decoupling (C1, C7).

How is switching frequency configured, and what resistor value sets 500kHz?

Frequency is set by a resistor between fSET and AGND. Per the datasheet and BOM, R2 = 60.4kΩ configures 500kHz; values from 400kHz to 1MHz are achievable using 30.1kΩ to 75kΩ resistors, as confirmed in the MPM3690-20B's fSET transfer function.

Does the board support PMBus communication, and which signals are exposed?

Yes-it includes a 10-pin PMBus connector (CN7) supporting SMBus 2.0, with SCL, SDA, ALERT#, and VDD exposed. Telemetry includes real-time VOUT, IOUT, temperature, and fault flags, validated in the "EVB TEST RESULTS" section showing VPG monitoring waveforms.

What is the purpose of the MODE and PMODE pins, and how are they configured?

MODE selects CCM/DCM operation; PMODE enables pulse-skipping mode for light-load efficiency. On this board, both are pulled to GND via 0Ω resistors (R3, R4), defaulting to forced CCM and standard PWM-verified in the schematic and BOM.

Can the output voltage be adjusted, and what components define the default 1.2V setting?

Yes-the default 1.2V is set by the FB1/FB2 resistive divider (R9 = R10 = 48kΩ) per phase, yielding VOUT = 0.6V × (1 + R9/R10) = 1.2V. The schematic shows direct access to FB nodes and optional zero-ohm jumpers for reconfiguration.

What thermal performance is measured, and under what conditions?

At 26A load, no forced airflow, and ambient 28°C, case temperature reaches 57.6°C-measured at the thermal pad center of the MPM3690-20B module (U1), as reported in the "Thermal Performance" plot on page 5 of the document.