Monolithic Power Systems Inc. MP20046DN-S-LF

Overview

MP20046DN-S-LF from Monolithic Power Systems is a fast-transient-response, 2A low-dropout linear regulator with 3.3V fixed output, 210mV dropout at 2A, 70dB PSRR at 100Hz, and open-drain power-good (PG) output. It uses an internal PMOS pass element to achieve 75μA ground current at full load and 1μA shutdown current, making it suitable for FPGA and DSP core supplies in telecom infrastructure.

For engineers reviewing the MP20046DN-S-LF datasheet, MP20046DN-S-LF pinout, MP20046DN-S-LF application, or MP20046DN-S-LF equivalent, key selection criteria include dropout voltage under 2A load, PG threshold accuracy (78–86% VOUT), thermal shutdown at +150°C, and compatibility with low-ESR ceramic output capacitors (≤1.5Ω).

Technical Context

The MP20046DN-S-LF implements a PMOS-based LDO architecture with integrated error amplifier, bandgap reference, and current-limiting circuitry. Its fast transient response stems from high-loop-gain compensation optimized for 47μF ceramic output capacitors and low-ESR stability.

It features active power-good monitoring with hysteresis (1.15% VOUT), negative-enable logic (EN low = ON), and thermal foldback that disables the PMOS above +150°C junction temperature, re-enabling only after a 20°C cooldown.

Key Specifications

Pinout & Package

MP20046DN-S-LF is housed in a thermally enhanced SOIC8E package with exposed pad, supporting up to 2.0W power dissipation at +25°C ambient. The exposed pad must be soldered to a PCB ground plane for optimal thermal performance.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS7A4700RGWR and ADM7172ACPZ-R7, MP20046DN-S-LF uniquely combines integrated SENSE, auto-recovering thermal protection, and open-drain PG in SOIC8E-reducing BOM count by 3 passive components while maintaining 210mV dropout and 17μVRMS noise.

Availability

MP20046DN-S-LF is available at Aetrix Electronics and suitable for telecom infrastructure, FPGA power delivery, and battery-powered test equipment requiring stable component supply with RoHS-compliant packaging and tape-and-reel logistics.

Supply support for MP20046DN-S-LF 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 mixed-signal ICs for power management, motion control, and automotive applications.

The MP20046 belongs to MPS's fast-transient LDO product line, engineered specifically for high-current, low-noise point-of-load regulation in space-constrained telecom and computing systems.

FAQ

What is the minimum input voltage required for MP20046DN-S-LF to regulate 3.3V output at 2A?

The minimum input voltage is 3.51V, calculated as VOUT + VDO = 3.3V + 0.21V. This value is confirmed in the Electrical Characteristics table under Dropout Voltage (210mV at 2A, VOUT=3.2V). Operation below this voltage results in unregulated output and PG deassertion.

Can MP20046DN-S-LF operate without the SENSE pin connected?

Yes, but with degraded load regulation. The SENSE pin is optional for local sensing; if left unconnected, the device defaults to local feedback using the VOUT pin, increasing output voltage error by up to 4mV under full 2A load due to PCB trace resistance.

How does the EN pin logic function, and what happens if it is left floating?

The EN pin uses negative logic: low voltage (≤0.4V) enables regulation; high voltage (≥1.5V) disables it. Floating EN is prohibited-it may cause erratic enable/disable behavior due to noise coupling; the datasheet mandates tying EN to GND for always-on operation or to a controlled logic signal.

What is the maximum allowable output capacitance for stable operation?

No upper limit is specified; stability is ensured with ceramic capacitors ≥47μF and ESR ≤1.5Ω. Larger values (e.g., 100μF) improve transient response and reduce noise but increase inrush current and startup time-designers should verify soft-start behavior in their specific layout.

Does MP20046DN-S-LF require an input capacitor, and what value is recommended?

Yes-an input bypass capacitor is mandatory for stability. A 47μF X5R/X7R ceramic capacitor placed within 5mm of VIN/GND pins is recommended. For high-dI/dt applications, a parallel 1nF ceramic capacitor further suppresses high-frequency ringing observed in transient waveforms.

How is power-good (PG) asserted, and what external components are needed?

PG is an open-drain output requiring an external pull-up resistor to a valid logic rail (e.g., 3.3V). It asserts low when VOUT drops below 78% of nominal (2.574V for 3.3V version); typical pull-up is 10kΩ, yielding <1μs delay and compatible with standard CMOS reset inputs.

What thermal derating applies when operating above +25°C ambient?

Derating follows θJA = 50°C/W for SOIC8E: maximum power dissipation drops linearly from 2.0W at +25°C to zero at +125°C ambient. At +70°C ambient, max safe dissipation is (125−70)/50 = 1.1W, limiting practical 2A operation to VIN ≤ 3.85V to stay within thermal limits.