Monolithic Power Systems Inc. MP20045DN-33-LF-Z

Overview

MP20045DN-33-LF-Z from Monolithic Power Systems is a low-noise, 1A low-dropout linear regulator with fixed 3.3V output, 140mV dropout at 1A, 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. It powers noise-sensitive analog rails in portable battery-powered systems.

For engineers reviewing the MP20045DN-33-LF-Z datasheet, MP20045DN-33-LF-Z pinout, MP20045DN-33-LF-Z application, or MP20045DN-33-LF-Z equivalent, key selection criteria include dropout voltage under full load, PSRR at 1kHz, quiescent current across temperature, and SOIC8E thermal performance for space-constrained industrial handhelds.

Technical Context

The MP20045DN-33-LF-Z integrates a PMOS-based super-low-dropout regulation architecture with internal 1.5V feedback reference and precision bandgap control. Its fixed 3.3V output eliminates external resistor dividers while maintaining ±2.5% output accuracy over load and line variations.

It implements dual-level protection: foldback current limiting (1.6A short-circuit, 1.4–3.0A in-regulation limit) and thermal shutdown at 150°C with 20°C hysteresis. The open-drain PG pin asserts low when VOUT drops below 94% of nominal, enabling system-level power sequencing and fault monitoring.

Key Specifications

Pinout & Package

MP20045DN-33-LF-Z is housed in an SOIC8E package (5.0mm × 6.2mm × 1.75mm), featuring exposed pad thermal enhancement connected to GND. The 8-pin layout supports high-current routing and efficient heat dissipation on standard 2-layer PCBs.

Key Features

Applications

Equivalent & Alternatives

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

Compared with XC6210B332MR-G and ADP1740ACPZ-3.3-R7, MP20045DN-33-LF-Z uniquely combines 1A capability, 13μVRMS noise, 140mV dropout, and integrated PG in SOIC8E-enabling single-component solutions for noise-critical, thermally constrained, and sequenced-power embedded systems.

Availability

MP20045DN-33-LF-Z is available at Aetrix Electronics and suitable for portable medical sensors, industrial handheld scanners, wireless audio transceivers, and smart meter communication modules requiring stable component supply, RoHS-compliant packaging, and long-term production continuity.

Supply support for MP20045DN-33-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 design centers across Asia and North America.

The MP20045 product line targets battery-powered and noise-sensitive applications, delivering ultra-low-noise, low-quiescent LDOs optimized for portable instrumentation, wireless communications, and industrial handheld equipment.

FAQ

What is the maximum allowable input voltage for MP20045DN-33-LF-Z?

The absolute maximum input voltage is +6V referenced to GND. However, the recommended operating range is 2.5V to 5.5V. Exceeding 5.5V risks permanent damage due to internal overvoltage stress on the PMOS pass element and bandgap reference circuitry, even with brief transients.

Does MP20045DN-33-LF-Z require an external feedback resistor network?

No. As a fixed-output variant, MP20045DN-33-LF-Z has internal feedback tied to generate 3.3V. The FB pin is internally connected to VOUT and must not be externally modified-adding resistors will disrupt regulation and may cause instability or overvoltage.

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

The PG pin remains high-impedance until VOUT reaches 94% of 3.3V (≈3.1V); it then pulls low only when VOUT falls below that threshold. During startup, PG asserts low after ~100μs delay once regulation is achieved; during dropout, it releases high only after VOUT recovers fully and remains stable for >10μs.

Can MP20045DN-33-LF-Z sustain 1A output continuously in SOIC8E package?

Yes, but thermal design is critical: at TA=+25°C with 2-layer board and full GND pad connection, it sustains 1A with junction temperature ≤125°C. At TA=+60°C, derating to ~750mA is required. θJA is 50°C/W; exceeding TJ=125°C triggers thermal shutdown.

Is the EN pin internally pulled up or must it be externally biased?

The EN pin has no internal pull-up; it contains a 550kΩ to 1.1MΩ internal pull-down resistor. To ensure reliable turn-on, EN must be driven above 1.5V (e.g., tied to VIN or MCU GPIO). Leaving EN floating causes unpredictable behavior due to noise susceptibility and undefined logic state.

What output capacitor ESR range ensures stability for MP20045DN-33-LF-Z?

A 2.2μF ceramic capacitor with ESR ≤0.9Ω is required for guaranteed stability across all loads and temperatures. Capacitors with ESR >0.9Ω risk oscillation, especially near 1A load; X7R/X5R dielectrics are preferred over Z5U for consistent ESR over temperature and bias.