Monolithic Power Systems Inc. MP2040DU-LF-Z

Overview

MP2040DU-LF-Z from Monolithic Power Systems is a dual-supply, very low dropout linear regulator delivering up to 3A output current with 150mV dropout at full load, adjustable output from 0.9V to 3.3V, and fast transient response optimized for post-regulation of switching supplies in DSP/ASIC/μC power rails.

For engineers reviewing the MP2040DU-LF-Z datasheet, MP2040DU-LF-Z pinout, MP2040DU-LF-Z application, or MP2040DU-LF-Z equivalent, key selection criteria include dual-supply architecture (VIN + BIAS), ultra-low ESR capacitor stability (≥1µF ceramic), 0.51V feedback threshold, open-drain PGOOD signaling, and thermal/current protection behavior under high-current transient loads.

Technical Context

The MP2040DU-LF-Z employs a dual-rail architecture: the BIAS supply (3.3–5.5V) powers internal reference and control circuitry, while VIN (1.1–5.5V) feeds the NMOS pass device directly-enabling regulation even when VIN is only ~200mV above VOUT. This decouples drive efficiency from input headroom.

Its feedback loop uses a precision 0.51V reference with ±2% output accuracy, supports soft-start (280µs), and delivers 40dB PSRR at 100kHz. The open-drain PGOOD asserts after VOUT reaches 90% of target with 80µs delay and sinks ≥230µA when active low.

Key Specifications

Pinout & Package

MP2040DU-LF-Z is housed in a RoHS-compliant 5mm × 5mm QFN-32 package with exposed thermal pad (Pin 8). Pin count and layout match Monolithic Power's standard QFN32 footprint for industrial-grade thermal performance (θJA = 36°C/W on 4-layer PCB).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar dual-supply LDO applications.

Compared with TPS7A8300RGRT and ADM7172ACPZ-R7, MP2040DU-LF-Z uniquely supports 3A output with <200mV dropout via its dual-supply topology-making it the only viable option among the three for high-current, low-headroom digital core regulation where efficiency and thermal margin are prioritized over ultra-low noise.

Availability

MP2040DU-LF-Z is available at Aetrix Electronics and suitable for telecom infrastructure, industrial process control, and embedded computing applications requiring stable component supply, RoHS-compliant packaging, and long-term production continuity.

Supply support for MP2040DU-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 power management ICs, including DC/DC converters, LDOs, LED drivers, and motor drivers for industrial, telecom, and computing markets.

The MP2040 belongs to MPS's high-current, fast-transient LDO product line-designed specifically for post-regulation of switching power supplies in digital signal processing, ASIC, and microcontroller applications demanding tight voltage accuracy and rapid load-step response.

FAQ

What is the minimum required voltage difference between BIAS and VOUT?

The BIAS supply must be at least 2.5V greater than the regulated output voltage (VOUT) to ensure proper internal circuit operation and gate drive for the NMOS pass device. For example, setting VOUT = 3.3V requires BIAS ≥ 5.8V-exceeding the device's absolute maximum BIAS rating of 6V. Therefore, maximum VOUT is limited to 3.3V only when BIAS = 5.5V, per datasheet specification.

Can MP2040DU-LF-Z operate with VIN equal to VOUT?

No-VIN must exceed VOUT by at least the dropout voltage (150mV at 3A) to maintain regulation. However, due to the dual-supply architecture, VIN can be as low as VOUT + 150mV while BIAS remains at 3.3–5.5V, enabling operation with significantly less headroom than conventional single-supply LDOs.

How does the BYPASS pin function, and what capacitor value is required?

The BYPASS pin connects to a 1nF capacitor to control internal soft-start timing (280µs). This capacitor must be placed directly at the pin with no series resistance; resistive loading will disrupt soft-start behavior and may cause startup failure. It does not serve as a noise filter or reference bypass.

Is the PGOOD output compatible with 1.8V logic systems?

Yes-the PGOOD pin is open-drain and requires an external pull-up resistor. To interface with 1.8V logic, connect the pull-up to a 1.8V supply (within the pin's 0–5.5V rating). When active low, PGOOD sinks ≥230µA, ensuring reliable logic-level assertion across voltage domains.

What thermal derating applies above 85°C ambient?

At TA = 85°C, maximum continuous power dissipation is limited to 1.96W (calculated as (125°C − 85°C)/36°C/W). Exceeding this causes thermal shutdown. Derating is linear: for every 1°C rise in TA above 85°C, allowable power drops by 27.8mW. PCB copper area and airflow significantly impact real-world thermal margin.

Does MP2040DU-LF-Z support remote sensing?

No-MP2040DU-LF-Z lacks dedicated sense pins and relies on FB-connected resistive divider at the output node. For applications requiring compensation of PCB trace IR drop, external Kelvin sensing must be implemented using discrete op-amp circuitry; the IC itself does not provide remote-sense functionality.