Monolithic Power Systems Inc. MP6401DQT-25AD3-LF-Z

Overview

MP6401DQT-25AD3-LF-Z from Monolithic Power Systems is a 300mA low-dropout linear regulator with integrated push-pull active-low reset circuit, delivering ±2% output voltage accuracy at 2.5V fixed output, operating from 2.5V–5.5V input, and featuring 114mV dropout at full load. It supports -7.5% reset threshold and 200ms reset delay, targeting power management in space-constrained portable electronics.

For engineers reviewing the MP6401DQT-25AD3-LF-Z datasheet, MP6401DQT-25AD3-LF-Z pinout, MP6401DQT-25AD3-LF-Z application, or MP6401DQT-25AD3-LF-Z equivalent, key selection criteria include fixed 2.5V output, integrated reset timing (200ms), thermal/short-circuit protection, ultra-low 15μVRMS noise, and TQFN8 (3mm×3mm) package compatibility with high-density PCB layouts.

Technical Context

The MP6401DQT-25AD3-LF-Z integrates a precision bandgap reference, error amplifier, and PMOS pass transistor to regulate output with 2% accuracy across -40°C to +85°C. Its reset comparator continuously monitors VOUT against a -7.5% threshold relative to nominal 2.5V, triggering a push-pull RESET signal after a factory-programmed 200ms delay.

EN enables high-side control of regulation, while ADJ is internally tied to GND for fixed 2.5V operation-no external resistors required. Reverse leakage protection actively blocks OUT-to-IN current when VIN < VOUT, limiting reverse current to ≤1μA under specified conditions.

Key Specifications

Pinout & Package

TQFN8 (3mm × 3mm) package with exposed thermal pad; RoHS-compliant, lead-free finish; rated for -40°C to +85°C ambient operation.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar LDO-with-reset applications.

Compared with TPS79925DBVR and MCP1825-2502E/DB, MP6401DQT-25AD3-LF-Z uniquely combines 300mA delivery, factory-trimmed 200ms reset delay, push-pull RESET output, and 114mV dropout-enabling single-chip power sequencing in compact portable designs without design compromises.

Availability

MP6401DQT-25AD3-LF-Z is available at Aetrix Electronics and suitable for smartphone baseband power, portable GPS receivers, wireless headset audio codecs, and PDA application processor rails requiring stable component supply, long-term lifecycle assurance, and RoHS-compliant packaging.

Supply support for MP6401DQT-25AD3-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 in the US, China, and Taiwan, and global manufacturing partnerships.

The MP6401 product line targets space- and power-constrained portable electronics, integrating LDO regulation and microprocessor reset into a single die to eliminate discrete solutions and simplify power architecture.

FAQ

What is the function of the ADJ pin on MP6401DQT-25AD3-LF-Z?

The ADJ pin is internally connected to GND in this variant to select fixed 2.5V output mode. It must not be left floating or externally biased-doing so may cause regulation instability or incorrect reset behavior. No external resistors are required or recommended.

Can MP6401DQT-25AD3-LF-Z operate with input voltage below 2.5V?

No. The absolute minimum input voltage is 2.5V per datasheet specifications. Below this, the UVLO circuit disables regulation and asserts RESET. Input voltage must remain ≥2.5V for functional operation, with dropout headroom required for load current.

How does the reset delay time of 200ms get programmed in MP6401DQT-25AD3-LF-Z?

The 200ms delay is factory-programmed via internal trimming during wafer test and is encoded in the part number suffix "D3". It cannot be modified externally-no pins, registers, or external components adjust this timing. The delay is guaranteed over temperature and process variation.

Is the RESET output truly push-pull, and what are its drive capabilities?

Yes. RESET is a true push-pull output capable of sinking 3.2mA at 0.4V and sourcing 500μA at 0.8×VOUT. This eliminates the need for an external pull-up resistor and ensures fast, rail-to-rail transitions compatible with modern μP reset inputs.

What thermal derating applies to MP6401DQT-25AD3-LF-Z in a typical 4-layer PCB layout?

With standard JEDEC JESD51-7 4-layer board, θJA is 48°C/W. At 85°C ambient and 300mA load with 3.3V input, power dissipation is ~240mW, resulting in ~11.5°C junction rise-well below the 150°C shutdown threshold. No forced airflow or heatsink is required under these conditions.

Does MP6401DQT-25AD3-LF-Z support backup battery operation?

Yes. When main input is removed, reverse leakage protection disables the pass device, allowing external backup sources (e.g., coin cell or supercap) to maintain VOUT. RESET asserts during input removal, enabling controlled system hibernation while preserving RAM contents.

What is the minimum output capacitance required for stability?

A minimum of 3.3μF ceramic capacitor (X5R/X7R dielectric) is required on the OUT pin. Lower values risk oscillation; larger values (e.g., 10μF) improve transient response and PSRR. ESR must be <100mΩ-standard MLCCs meet this requirement.