Monolithic Power Systems Inc. EVL2491N-QB-00A

Overview

EVL2491N-QB-00A from Monolithic Power Systems is a fully assembled evaluation board for the MP2491N 32V, 6A synchronous step-down converter. It demonstrates high-efficiency DC/DC conversion with 5V fixed output, 540kHz switching frequency, constant-on-time (COT) control, and full protection including OCP, OVP, and thermal shutdown - validated at 91.9% efficiency (24V→5V/6A).

For engineers reviewing the EVL2491N-QB-00A datasheet, EVL2491N-QB-00A pinout, EVL2491N-QB-00A application, or EVL2491N-QB-00A equivalent, this board enables rapid validation of input range (16–32V), load transient response (0–6A), output ripple, thermal rise, and mode selection (PFM/PWM) under real PCB layout and component conditions.

Technical Context

The EVL2491N-QB-00A implements the MP2491N IC in a production-ready QFN-13 (2.5mm×3mm) footprint with optimized 4-layer PCB layout, MPL-AY1050-4R7 inductor (4.7µH, 15A ISAT), and low-ESR ceramic/electrolytic output capacitance (100µF + 4×22µF). Input filtering uses three parallel 10µF X5R 0805 capacitors.

It supports configurable operation modes via the MODE pin (0V = forced PWM; VCC = auto-PFM/PWM), features an EN resistor divider setting VIN UVLO threshold at 16V, and includes optional Schottky diode D1 for light-load efficiency enhancement - all verified per Rev. 1.0 test data at TA = 25°C.

Key Specifications

Availability

EVL2491N-QB-00A is available at Aetrix Electronics and suitable for industrial power supply validation, embedded system DC/DC qualification, and automotive auxiliary rail testing requiring stable component supply, repeatable test setups, and documented thermal performance.

Supply support for EVL2491N-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 power management ICs, with core expertise in DC/DC converters, LED drivers, and motor drivers for industrial, computing, and automotive markets.

The MP2491N product line targets high-voltage, high-current buck conversion in space-constrained applications - designed for reliability across 16–32V input ranges with minimal external components and robust protection.

FAQ

What input voltage range is supported, and how is undervoltage lockout configured?

The board accepts 16V to 32V input. Undervoltage lockout (UVLO) is set to 16V using an EN pin resistor divider (R5 = 24.9kΩ, R2 = 11.3kΩ). This ensures startup only when VIN exceeds 16V, preventing erratic operation during brownout conditions.

How is output voltage accuracy maintained during load transients?

Constant-on-time (COT) control provides sub-microsecond response to load steps up to 6A at 2.5A/µs. The 5V output remains within ±1.5% deviation due to fast loop dynamics, low-impedance output capacitance (100µF + 4×22µF), and Kelvin-sense routing (VOUTSENSE/GNDSEN).

Can the board operate in forced PWM mode, and how is it enabled?

Yes. Forced PWM mode is activated by pulling the MODE pin to 0V (ground). This disables automatic PFM entry at light loads, ensuring consistent switching frequency and predictable EMI behavior - critical for noise-sensitive analog or RF subsystems.

What thermal performance can be expected at full 6A load?

At 24V→5V/6A, case temperature rise is ≤60°C above ambient on a 63.5mm×63.5mm 4-layer PCB. Thermal vias under the MP2491N QFN-13 package and copper pour on inner layers enable reliable conduction cooling without forced airflow.

Is the optional D1 Schottky diode required for basic operation?

No. D1 (1N5819) is optional and improves light-load efficiency by enabling diode emulation in PFM mode. It is omitted by default and only installed when optimizing for ultra-low standby power in battery-backed or energy-harvesting systems.

How are output voltage ripple measurements performed on this board?

Ripple is measured differentially between VOUTSENSE and GNDSEN terminals using AC-coupled oscilloscope channels. Test points are routed with short, symmetric traces to minimize probe-induced noise - yielding <25mVpp ripple at 6A (24V→5V) with proper probing technique.