Monolithic Power Systems Inc. EV9447-L-00A

Overview

EV9447-L-00A from Monolithic Power Systems is a fully assembled and tested evaluation board for the MP9447GL synchronous step-down converter, delivering 5A continuous output at 5V from a 7–36V input, with 500kHz switching frequency, integrated 65mΩ/30mΩ MOSFETs, and 1.5% reference voltage accuracy.

For engineers reviewing the EV9447-L-00A datasheet, EV9447-L-00A pinout, EV9447-L-00A application, or EV9447-L-00A equivalent, this board enables rapid validation of high-efficiency, fast-transient DC/DC conversion in USB power supplies, cigarette lighter adapters, and consumer charger designs under real load and line conditions.

Technical Context

The EV9447-L-00A implements the MP9447GL IC in a fixed 5V output configuration, leveraging its proprietary switching-loss-reduction technology to maintain >92% peak efficiency across 7–36V input and 0–5A load. It operates in forced PWM mode with low dropout capability and supports programmable soft-start via external capacitor.

Board-level protection includes over-current (OCP), short-circuit (SCP), under-voltage lockout (UVLO) set by R5/R8 divider, and thermal shutdown. The EN pin accepts TTL-compatible logic control (1.25V turn-on, 0.86V turn-off threshold), enabling system-level sequencing and standby management.

Key Specifications

Availability

EV9447-L-00A is available at Aetrix Electronics and suitable for USB power supplies, cigarette lighter adapters, and consumer charger development requiring stable component supply, quick-turn prototyping, and production-ready reference design validation.

Supply support for EV9447-L-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 core expertise in DC/DC conversion, motor drivers, and LED lighting controllers.

The MP9447 product line targets high-density, high-efficiency buck converters for space-constrained consumer and automotive auxiliary power applications, emphasizing fast transient response and integrated MOSFET reliability.

FAQ

What input voltage range does the EV9447-L-00A support?

The board accepts 7V to 36V DC input, validated across this full range with stable 5V/5A output. Input below 7V triggers UVLO; above 36V risks damage to the MP9447GL IC and input capacitors. Operation at 24V nominal yields peak efficiency >93% per test reports.

Can the output voltage be adjusted from 5V?

Yes - the board uses R1 (53.6kΩ) and R2 (10kΩ) to set VOUT = 5V via the MP9447GL's 0.815V feedback reference. Replacing R1 allows adjustment; formula is R1 = 12.27 × (VOUT − 0.815) kΩ. Compensation and output capacitor selection must be re-verified per MPS AN-107.

How is enable/disable controlled on this evaluation board?

The EN pin accepts a digital signal: drive >1.25V to enable regulation, <0.86V to disable. The board includes no pull-up; users must supply external logic or switch. EN is not internally tied, allowing flexible sequencing with microcontrollers or power supervisors.

Does the EV9447-L-00A include input or output reverse polarity protection?

No - the board lacks dedicated reverse-polarity circuitry on VIN or VOUT. Input reverse voltage beyond diode drop may damage input capacitors or the MP9447GL. Users must add external protection (e.g., ideal diode or series MOSFET) if required by application.

What is the thermal performance under full 5A load?

At 24V input and 5A load, the MP9447GL junction temperature rises ~45°C above ambient (measured per Rev. 1.0 test report). The QFN20 package relies on PCB copper pour for heat dissipation; recommended minimum 4-layer board with thermal vias is not implemented on this 2-layer EVB.

Is the schematic and layout file available for this board?

Yes - the official EV9447-L-00A Rev. 1.0 documentation (dated 5/1/2018) includes full schematic, BOM, layer-by-layer PCB layout (Figures 1–5), and bill of materials with manufacturer part numbers for all passives and the MP9447GL IC.