Monolithic Power Systems Inc. EVM3805A-QB-00A

Overview

EVM3805A-QB-00A from Monolithic Power Systems is an evaluation board for the MPM3805A synchronous step-down switcher IC, designed to demonstrate high-efficiency 0.6A peak DC/DC conversion from 2.5–6V input to adjustable 0.6–3.3V output in space-constrained automotive and portable applications. It integrates the MPM3805AGQB QFN3.0×2.5mm IC with built-in MOSFETs and power inductor, uses constant-on-time (COT) control for fast transient response, and includes cycle-by-cycle current limiting and thermal shutdown.

For engineers reviewing the EVM3805A-QB-00A datasheet, EVM3805A-QB-00A pinout, EVM3805A-QB-00A application, or EVM3805A-QB-00A equivalent, this board enables rapid validation of low-voltage, high-frequency buck regulation performance-including load/line regulation, efficiency across input voltage ranges (2.5V–6V), startup/shutdown behavior, enable sequencing, and hiccup-mode short-circuit recovery-under real-world PCB layout and thermal conditions.

Technical Context

The EVM3805A-QB-00A implements a complete 0.6A peak COT-controlled buck converter using the MPM3805AGQB IC, which embeds high- and low-side MOSFETs, a shielded power inductor, and internal compensation. Its 3.0×2.5×0.9mm QFN package supports total solution size of just 6×3.8mm.

Test data confirms stable operation across 2.5–6V input, 0.6–3.3V output (default 1.2V), with ≤±1.5% load regulation at 0.6A and ≤±0.5% line regulation over full VIN range at 0.3A load; shutdown current remains below 0.5µA at 6V input.

Key Specifications

Availability

EVM3805A-QB-00A is available at Aetrix Electronics and suitable for automotive ECU power design, portable product system supply, and LDO replacement applications requiring stable component supply, fast technical validation cycles, and traceable reference hardware.

Supply support for EVM3805A-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 expertise in integrated power modules, DC/DC converters, and motor drivers for automotive, industrial, and consumer markets.

The MPM3805A product line delivers fully integrated, ultra-small synchronous buck modules targeting space- and efficiency-critical applications such as automotive infotainment, telematics, and battery-powered IoT sensors where minimal external components and fast transient response are essential.

FAQ

What is the default output voltage and how is it configured?

The default output voltage is 1.2V, set by a 40.2kΩ/40.2kΩ resistor divider on the FB pin. Output can be adjusted from 0.6V upward by changing R2 per the formula R2 = R1 × (0.6/VOUT − 1), with R1 recommended between 40kΩ and 80kΩ for optimal noise immunity and bias current.

Does the board support power sequencing via EN and PG signals?

Yes - the board exposes both EN (enable) and PG (power good) pins from the MPM3805A. EN accepts 1.2–6V logic-level input for controlled startup/shutdown, while PG asserts high when VOUT is within ±7.5% of target, enabling reliable multi-rail sequencing in automotive and industrial systems.

What protection features are implemented and how do they behave under fault?

The board demonstrates cycle-by-cycle current limiting and thermal shutdown from the MPM3805A. During sustained overload or short circuit, it enters hiccup mode - latching off for ~30ms, then attempting restart - verified in test waveforms showing clean recovery without latch-up or thermal runaway at 5V input.

Can this board operate at 100% duty cycle, and what is the minimum dropout voltage?

Yes - the MPM3805A supports 100% duty cycle operation, allowing VOUT to track VIN down to ~100mV dropout. At 2.5V input and 1.2V output, the board maintains regulation with measured line regulation <±0.3% and no observed dropout-induced instability in steady-state or transient tests.

What external components are required to change the output voltage?

Only two external resistors (R1 and R2) forming the feedback divider are needed - no additional capacitors, inductors, or compensation networks. The board already includes all required input/output ceramic capacitors (10µF and 0.1µF) and layout-optimized power paths, making it a true 2-component-adjustable solution.

Is the board RoHS-compliant and lead-free?

Yes - all components on the EVM3805A-QB-00A, including the MPM3805AGQB IC, Murata capacitors, and film resistors, are lead-free, halogen-free, and fully compliant with the EU RoHS directive, as confirmed in the official MPS Bill of Materials and green status documentation.