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

Overview

MP6401DQT-25AD3-LF-P from Monolithic Power Systems is a 300mA low-dropout linear regulator with integrated push-pull active-low reset circuit, fixed 2.5V output (±2% accuracy), -7.5% reset threshold, and 200ms reset delay. It operates from 2.5V to 5.5V input, delivers 114mV dropout at full load, and features 15μVRMS output noise and 57dB PSRR at 1kHz. Used in smartphone power rails requiring precise voltage regulation and microprocessor supervision.

For engineers reviewing the MP6401DQT-25AD3-LF-P datasheet, MP6401DQT-25AD3-LF-P pinout, MP6401DQT-25AD3-LF-P application, or MP6401DQT-25AD3-LF-P equivalent, this device supports compact portable designs where simultaneous LDO regulation and deterministic reset timing are required-especially where battery life, low noise, and brownout immunity are critical.

Technical Context

The MP6401 integrates an error amplifier-based LDO control loop with a dedicated reset comparator monitoring the regulated output. Its ADJ pin selects between fixed-output mode (GND-connected) and adjustable mode (resistor-divider-connected), enabling flexible voltage configuration without external components for standard outputs.

The reset function uses a precision voltage threshold detector (-7.5% of nominal VOUT) with four factory-selectable delay options; the D3 suffix confirms 200ms typical assertion-to-deassertion delay. RESET is push-pull, eliminating need for external pull-up and ensuring fast, low-impedance deassertion after recovery.

Key Specifications

Pinout & Package

MP6401DQT-25AD3-LF-P is housed in a 3mm × 3mm TQFN-8 package with exposed thermal pad, optimized for high-density PCB layouts and efficient heat dissipation in space-constrained handheld applications.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS79925DRVR and MCP1826-2502E/DB, MP6401DQT-25AD3-LF-P uniquely integrates accurate output-voltage monitoring, factory-trimmed reset threshold (-7.5%), and fixed 200ms delay-enabling single-chip power-good supervision without external timing or sensing components.

Availability

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

Supply support for MP6401DQT-25AD3-LF-P 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 and global manufacturing partnerships.

The MP6401 belongs to MPS's integrated power management portfolio, designed specifically for space- and power-constrained portable electronics where combining regulation and reset functionality reduces system-level cost and footprint.

FAQ

What is the exact reset threshold voltage for MP6401DQT-25AD3-LF-P?

The reset threshold is -7.5% of the nominal 2.5V output, equating to 2.3125V. The device asserts RESET when VOUT falls below this value and deasserts after the 200ms delay once VOUT recovers above the threshold. This value is factory-trimmed and specified across temperature.

Can the ADJ pin be left unconnected for fixed 2.5V operation?

No. For fixed 2.5V output, the ADJ pin must be connected directly to GND. Leaving it floating violates the datasheet requirement and may cause output instability or incorrect regulation. The impedance between ADJ and GND must remain below 50kΩ in fixed-mode operation.

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

Yes. When main input is removed, the device allows reverse current protection to engage, limiting OUT-to-IN leakage to ≤1μA. With external diodes or current-limiting resistors, a backup battery can maintain VOUT and preserve RAM content, as confirmed in Figure 4 of the datasheet.

What is the minimum output capacitor required for stability?

A minimum 3.3μF low-ESR ceramic capacitor is required at the OUT pin. X5R or X7R dielectrics are recommended. Larger values (e.g., 10μF) improve transient response and PSRR but are not mandatory for basic stability per the datasheet.

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

Yes. RESET is a true push-pull output: it actively drives low (≤0.4V at 3.2mA sink) and high (≥0.8×VOUT at 500μA source). No external pull-up is needed, and it interfaces directly with standard CMOS /RESET inputs without level-shifting.

How does thermal shutdown behave during continuous overload?

Thermal shutdown activates at TJ = 150°C (typical) and releases at TJ = 130°C (20°C hysteresis). During sustained overload, the device cycles on/off, limiting average power dissipation. Junction temperature must be kept ≤125°C for reliable long-term operation.

What package variant does the "DQT" suffix indicate?

"DQT" denotes the 3mm × 3mm TQFN-8 package with exposed thermal pad. This differs from "DGT" (2mm × 2mm TQFN-6) and "DJ" (TSOT23-6); the DQT variant offers superior thermal performance (θJA = 48°C/W) and dual-output/GND pins for lower impedance paths.