Monolithic Power Systems Inc. MP6401DGT-33AD3-LF-P

Overview

MP6401DGT-33AD3-LF-P from Monolithic Power Systems is a 300mA low-dropout linear regulator with integrated push-pull active-low reset circuit, fixed 3.3V output (±2% accuracy), -7.5% reset threshold, and 200ms reset delay. It operates from 2.5V–5.5V input, delivers 114mV dropout at full load, and targets space-constrained portable electronics requiring regulated power and reliable microprocessor supervision.

For engineers reviewing the MP6401DGT-33AD3-LF-P datasheet, MP6401DGT-33AD3-LF-P pinout, MP6401DGT-33AD3-LF-P application, or MP6401DGT-33AD3-LF-P equivalent, this device serves as a single-chip solution for voltage regulation and power-on reset in battery-powered smart phones, GPS modules, and wireless edge devices where quiescent current (80μA), noise (15μVRMS), and thermal protection are critical selection criteria.

Technical Context

The MP6401 integrates an LDO regulator core with a dedicated reset comparator monitoring the OUT pin against a precision internal reference. Its reset logic asserts when VOUT falls below 92.5% of nominal (–7.5% threshold) and deasserts after a factory-programmed 200ms delay, independent of EN state once triggered.

Regulation uses an internal error amplifier driving a PMOS pass element with reverse-current protection, thermal shutdown (150°C trip), and current limiting (500mA). The ADJ pin enables either fixed-output mode (GND-connected) or adjustable mode (resistor-divider feedback), with 1.229V reference voltage and ±2% output accuracy over –40°C to +85°C.

Key Specifications

Pinout & Package

MP6401DGT-33AD3-LF-P is housed in a 2mm × 2mm TQFN6 package with exposed thermal pad, optimized for compact PCB layouts and efficient heat dissipation in handheld devices.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS79933DRVR and MCP1826-3302E/DB, MP6401DGT-33AD3-LF-P uniquely combines fixed 3.3V regulation, autonomous VOUT-monitored reset, and factory-set 200ms delay in one TQFN6 package-reducing bill-of-materials, layout effort, and qualification risk for portable consumer electronics.

Availability

MP6401DGT-33AD3-LF-P is available at Aetrix Electronics and suitable for smartphone baseband power, portable GPS modules, and wireless sensor nodes requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for MP6401DGT-33AD3-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 mixed-signal ICs for power management, motion control, and automotive applications.

The MP6401 belongs to MPS's integrated power-supervision LDO product line, designed specifically to replace discrete regulator + supervisor combinations in space- and power-constrained portable electronics.

FAQ

What is the function of the ADJ pin on MP6401DGT-33AD3-LF-P?

The ADJ pin selects operating mode: when tied to GND, it configures the device for fixed 3.3V output; it is not used for feedback in this variant. Leaving ADJ floating or connecting it to high-impedance nodes may cause regulation instability, so a direct GND connection or ≤50kΩ pull-down is mandatory for reliable fixed-voltage operation.

Does MP6401DGT-33AD3-LF-P require an external capacitor on the RESET pin?

No external capacitor is needed on the RESET pin. The 200ms delay is internally generated and factory-trimmed; the push-pull output drives directly into microcontroller reset inputs without pull-up resistors or timing capacitors, simplifying layout and improving noise immunity compared to open-drain reset ICs.

Can MP6401DGT-33AD3-LF-P operate with input voltage below 2.5V?

No. The absolute minimum input voltage is 2.5V per datasheet specifications. Below this, the internal UVLO circuit disables regulation and asserts RESET. Attempting operation at 2.4V or lower will result in unregulated output and undefined reset behavior, risking system malfunction.

How does the reset threshold tolerance affect system reliability?

The –7.5% threshold has ±2.5% tolerance (90–95% of nominal), meaning RESET asserts between 2.97V and 3.135V for a 3.3V output. This ensures robust detection of marginal supply conditions before microprocessor functional failure, while avoiding nuisance resets during brief transients within specification limits.

Is thermal pad soldering required for MP6401DGT-33AD3-LF-P?

Yes. The exposed thermal pad on the TQFN6 package must be soldered to a PCB thermal pad with ≥4 thermal vias to an internal ground plane. Omitting this compromises thermal resistance (θJA rises from 80°C/W to >120°C/W), increasing junction temperature and triggering premature thermal shutdown under 300mA load.

What happens to RESET output during EN pin deactivation?

When EN is pulled low, the regulator shuts down, VOUT collapses, and RESET asserts within 30μs. The RESET output remains asserted as long as EN is low or VOUT remains below threshold - it does not auto-deassert until both EN is high AND VOUT recovers above the threshold for the full 200ms delay period.

Does MP6401DGT-33AD3-LF-P support backup battery operation?

Yes. Its reverse-current protection allows external backup batteries to maintain VOUT during main input removal. When VIN drops, RESET asserts, and the device draws only 40μA from the backup source - sufficient to retain SRAM contents in most microcontrollers without supplemental circuitry.