Monolithic Power Systems Inc. MP20045DQ-25-LF-P

Overview

MP20045DQ-25-LF-P from Monolithic Power Systems is a fixed-output 2.5V, 1A low-dropout linear regulator with 140mV dropout at full load, 110μA ground current, and 13μVRMS output noise. It uses an internal PMOS pass element and features open-drain power-good (PG) output, thermal shutdown, and current limiting. Designed for battery-powered handheld instruments requiring stable low-noise voltage regulation.

For engineers reviewing the MP20045DQ-25-LF-P datasheet, MP20045DQ-25-LF-P pinout, MP20045DQ-25-LF-P application, or MP20045DQ-25-LF-P equivalent, key selection criteria include dropout voltage at 1A, PSRR at 1kHz, PG threshold accuracy, thermal shutdown hysteresis, and QFN8 package thermal resistance.

Technical Context

The MP20045DQ-25-LF-P implements a super-low-dropout architecture using an internal PMOS pass transistor, enabling operation down to 2.5V input while maintaining 2.5V output. Its feedback loop references a precise 1.5V internal bandgap, ensuring ±2.5% output voltage accuracy across temperature and line/load conditions.

It integrates dual protection mechanisms: foldback current limiting (1.4–3.0A depending on VIN) and thermal shutdown at 150°C with 20°C hysteresis. The EN pin provides logic-level control with 1.5V turn-on threshold and 550kΩ internal pull-up, while the PG pin asserts low when VOUT drops below 80–86% of nominal.

Key Specifications

Pinout & Package

MP20045DQ-25-LF-P is housed in an 8-pin QFN package (3mm × 3mm, 0.5mm pitch) with exposed thermal pad connected to GND for optimal heat dissipation (θJA = 50°C/W on 4-layer board).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar low-noise, 1A LDO applications.

Compared with XC6210B252MR-G and ADP1740ACPZ-2.5-R7, MP20045DQ-25-LF-P delivers the lowest dropout (140mV) and lowest noise (13μVRMS) in its class, making it optimal for battery-critical and RF-sensitive designs where PG signaling and thermal robustness are mandatory.

Availability

MP20045DQ-25-LF-P is available at Aetrix Electronics and suitable for hand-held instruments, cordless telephones, modems, and PDA applications requiring stable component supply, RoHS-compliant packaging, and consistent QFN8 thermal performance.

Supply support for MP20045DQ-25-LF-P 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.

The MP20045 belongs to MPS's low-noise LDO product line, engineered specifically for battery-powered portable electronics demanding ultra-low dropout, minimal quiescent current, and high PSRR in compact QFN packages.

FAQ

What is the minimum input voltage required for MP20045DQ-25-LF-P to regulate 2.5V output at 1A?

The minimum input voltage is 2.64V, calculated as VOUT + dropout = 2.5V + 0.14V. This allows operation from a single Li-ion cell down to ~2.6V, supporting extended battery runtime in portable devices without brownout.

Does MP20045DQ-25-LF-P require an external feedback resistor network?

No. As a fixed-output variant, the FB pin is internally connected to the 2.5V output. External resistors are unnecessary - simplifying layout, reducing BOM count, and eliminating resistor tolerance errors affecting output accuracy.

How does the power-good (PG) pin behave during startup and fault conditions?

The PG pin remains high-impedance until VOUT reaches 80–86% of 2.5V (2.0–2.15V), then pulls low if VOUT drops below that threshold. During startup, it asserts high only after regulation is established, providing reliable power sequencing for microcontrollers.

Can MP20045DQ-25-LF-P be used with input voltages above 5.5V?

No. Absolute maximum VIN is +6V, but recommended operating range is strictly 2.5V to 5.5V. Exceeding 5.5V risks permanent damage per datasheet absolute maximum ratings - external clamping or pre-regulation is required for higher-input systems.

What is the thermal performance difference between QFN8 and SOIC8E packages at 1A load?

At 1A, QFN8 (θJA = 50°C/W) achieves ~25°C lower junction temperature than SOIC8E (same θJA) due to superior thermal pad conduction. With identical PCB layout, QFN8 enables full 1A operation up to +85°C ambient without derating, whereas SOIC8E may require current reduction.

Is the exposed thermal pad electrically isolated or must it be connected to GND?

The exposed pad is electrically connected to the internal GND node and must be soldered to a PCB GND plane. Leaving it unconnected degrades thermal performance by >30°C and violates JEDEC MO-229 mechanical compliance, risking long-term reliability failure.