Monolithic Power Systems Inc. EVM3805B-12-QB-00A

Overview

EVM3805B-12-QB-00A from Monolithic Power Systems is an evaluation board for the MPM3805B-12 synchronous step-down switcher IC, delivering a fixed 1.2V output at up to 0.6A peak current from a 2.5–6V input. It integrates power MOSFETs and inductor in a 3.0×2.5×0.9mm QFN package and uses constant-on-time (COT) control for fast transient response, with cycle-by-cycle over-current protection and thermal shutdown-designed for space-constrained low-voltage I/O power applications.

For engineers reviewing the EVM3805B-12-QB-00A datasheet, EVM3805B-12-QB-00A pinout, EVM3805B-12-QB-00A application, or EVM3805B-12-QB-00A equivalent, this board enables rapid validation of the MPM3805B-12's performance in automotive ECUs, portable product power rails, LDO replacement scenarios, and telematics subsystems under real-world load and line transients.

Technical Context

The EVM3805B-12-QB-00A implements the MPM3805B-12 buck converter in a fully assembled, tested layout with two 0.1µF ceramic input/output bypass capacitors (C2/C4), two 10µF bulk capacitors (C1/C3), and 100kΩ feedback resistors (R1/R2) configured for fixed 1.2V output. It supports 100% duty-cycle operation in dropout and operates in forced continuous conduction mode (CCM).

Test results confirm efficiency ≥90% at 0.3A with 5V input, <±0.2% load regulation across 0–0.6A, and <±0.3% line regulation from 2.5V to 6V-all measured at TA = 25°C. Short-circuit protection engages in hiccup mode, and enable (EN) and power-good (PG) signals support precise power sequencing.

Key Specifications

Availability

EVM3805B-12-QB-00A is available at Aetrix Electronics and suitable for automotive ECU development, portable device power validation, telematics subsystem testing, and space-limited embedded system prototyping requiring stable component supply and immediate functional verification.

Supply support for EVM3805B-12-QB-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 analog and power ICs, with design centers in the US, China, and Taiwan, and global manufacturing partnerships.

The MPM3805B-12 product line targets ultra-compact, high-efficiency DC/DC conversion for battery-powered and automotive applications where minimal external components and fast transient response are critical.

FAQ

What is the purpose of the EVM3805B-12-QB-00A evaluation board?

This board is a fully assembled reference design for the MPM3805B-12 integrated buck converter, enabling engineers to verify electrical performance-including efficiency, transient response, and protection behavior-without designing a custom PCB. It ships with all necessary passive components and test points for VIN, VOUT, EN, and PG signals.

Can the output voltage be adjusted from the default 1.2V?

No-the output is fixed at 1.2V by internal feedback resistors. The board lacks external feedback pads or resistor footprints; voltage adjustment requires replacing the IC with a version supporting adjustable output (e.g., MPM3805B-12-A) and redesigning the feedback network.

What input voltage range is validated on this board?

The board is characterized and guaranteed to operate across 2.5V to 6V input, with published efficiency, regulation, and transient data covering that full range. Operation below 2.5V may result in dropout or failure to start; above 6V risks damage to the MPM3805B-12 IC.

How is power sequencing implemented on this evaluation board?

EN and PG pins are routed to test points and support external control: EN enables/disables regulation, while PG asserts high when VOUT is within ±5% of 1.2V. These signals allow synchronization with other rails in multi-rail systems, such as automotive domain controllers or FPGA power trees.

Does this board include thermal management features?

Yes-the MPM3805B-12 IC incorporates thermal shutdown (TSD) that disables switching when die temperature exceeds ~150°C. The board's QFN package and exposed thermal pad (connected to PGND) provide direct heat path to the PCB, and test data confirms stable operation at 0.6A with no heatsink under 25°C ambient.

Are external components required to operate the board?

No-EVM3805B-12-QB-00A is fully populated with all required components: two 0.1µF ceramic bypass caps, two 10µF bulk caps, 100kΩ feedback resistors, and the MPM3805B-12 IC. Only a DC input source (2.5–6V), load, and optional scope probes are needed for functional evaluation.