Monolithic Power Systems Inc. MP20051DQ-LF-Z

Overview

MP20051DQ-LF-Z from Monolithic Power Systems is a low-noise, high-PSRR 1A linear regulator with 140mV dropout at 1A, 110μA ground current, and adjustable 0.8V–5V output across 2.5V–5.5V input. It uses an internal PMOS pass element and integrates thermal shutdown, short-circuit protection, and enable control-designed for power-sensitive RF and portable applications such as Wi-Fi transceivers and smartphone baseband supplies.

For engineers reviewing the MP20051DQ-LF-Z datasheet, MP20051DQ-LF-Z pinout, MP20051DQ-LF-Z application, or MP20051DQ-LF-Z equivalent, key selection criteria include dropout voltage under full load, PSRR at 1kHz (63dB), output noise (13μVRMS), thermal resistance (θJA = 50°C/W), and compatibility with ceramic output capacitors without external compensation.

Technical Context

The MP20051DQ-LF-Z implements a PMOS-based LDO architecture with fixed 0.8V feedback reference and externally adjustable output via resistor divider. Its low-quiescent-current design maintains regulation down to 110μA ground current at no load while delivering up to 1A continuous output.

It features integrated protection including thermal shutdown (150°C trip with 20°C hysteresis), current limiting (1.6A short-circuit limit), and UVLO (2.25V rising threshold). The EN pin provides logic-level on/off control with 1.5V high/0.4V low thresholds, and the exposed pad must be connected to GND for thermal performance.

Key Specifications

Pinout & Package

MP20051DQ-LF-Z is housed in a thermally enhanced 3mm × 3mm 8-pin QFN package with exposed GND pad on the underside. The package requires soldering the exposed pad directly to a PCB ground plane for optimal thermal performance (θJC = 12°C/W).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar LDO regulator applications.

Compared with XC6210B122MR-G and ADM7172ACPZ-R7, MP20051DQ-LF-Z delivers superior RF-grade noise performance (13μVRMS) and balanced PSRR (63dB) in a compact QFN-8, making it optimal for space-constrained, noise-sensitive portable designs where 1A capability and thermal efficiency are jointly critical.

Availability

MP20051DQ-LF-Z is available at Aetrix Electronics and suitable for notebook computers, cellular phones, wireless communication equipment, and hand-held instruments requiring stable component supply across production lifecycles.

Supply support for MP20051DQ-LF-Z 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 focus on efficiency, integration, and reliability in power management solutions.

The MP20051 belongs to MPS's low-noise, high-PSRR LDO product line, engineered specifically for powering noise-sensitive RF, analog, and mixed-signal circuits in portable and battery-operated systems.

FAQ

What is the minimum input voltage required for MP20051DQ-LF-Z to regulate a 1.1V output?

The MP20051DQ-LF-Z requires a minimum input voltage of 1.24V (1.1V + 140mV dropout) to maintain regulation at 1A load. However, its absolute minimum specified input is 2.5V per datasheet operating conditions-below which UVLO disables operation regardless of dropout margin.

Can MP20051DQ-LF-Z operate without an external feedback resistor divider?

No. The MP20051DQ-LF-Z has no fixed-output variant-it requires an external R1/R2 divider connected to the FB pin to set output voltage. The feedback threshold is fixed at 0.8V, so omitting the divider leaves the regulator unregulated.

Is the exposed pad on the QFN package electrically connected to GND internally?

Yes-the exposed pad is internally tied to the GND terminal and must be soldered to a PCB ground plane. It serves both as the primary thermal conduction path (θJC = 12°C/W) and as part of the electrical GND return, not merely a mechanical heatsink.

What is the maximum allowable output capacitance for MP20051DQ-LF-Z?

The datasheet specifies stability with ≥4.7μF ceramic output capacitors and does not define an upper limit. Larger values (e.g., 10–22μF) improve load transient response and reduce output ripple but increase inrush current and startup time-designers should verify soft-start behavior in their specific layout.

Does MP20051DQ-LF-Z support reverse-voltage protection?

No. The MP20051DQ-LF-Z lacks reverse-voltage protection. Absolute maximum rating for OUT-to-GND is –0.5V; applying reverse polarity to VOUT or VIN can damage the internal PMOS pass device and bandgap circuitry.

How does the EN pin behave during power-up when VIN ramps slowly?

The EN pin has hysteresis: it turns ON when VIN reaches ~1.5V (EN threshold) and remains ON until VIN drops below ~0.4V. During slow VIN ramp, the regulator activates only after VIN exceeds the EN high threshold-not at POR or UVLO release-ensuring controlled sequencing.