Monolithic Power Systems Inc. MP8903DG-3.3-LF-P

Overview

MP8903DG-3.3-LF-P from Monolithic Power Systems is a fixed-output 3.3V, 150mA low-dropout linear regulator with 2% output accuracy, 100mV dropout at 100mA, and operation from 2.7V to 6.5V input. It features thermal shutdown protection, stable operation with low-ESR ceramic capacitors, and is packaged in a 2×2mm QFN8 for space-constrained mobile power rails such as audio codec and PLL supply.

For engineers reviewing the MP8903DG-3.3-LF-P datasheet, MP8903DG-3.3-LF-P pinout, MP8903DG-3.3-LF-P application, or MP8903DG-3.3-LF-P equivalent, key selection criteria include dropout voltage under load, thermal resistance (θJA = 80°C/W), FB threshold (1.222V), EN logic compatibility, and QFN8 layout requirements for thermal performance.

Technical Context

The MP8903DG-3.3-LF-P uses a PMOS pass transistor architecture enabling low dropout and fast transient response. Its internal bandgap reference (1.222V) feeds a precision error amplifier that regulates output via feedback from the FB pin, supporting both fixed 3.3V output and adjustable configurations using external resistors.

Thermal protection activates at 155°C with 30°C hysteresis, and the device remains stable with 1–10µF X5R/X7R output capacitors. Shutdown current is ≤1μA when EN is pulled low, and PSRR reaches 50dB at 1kHz and 20dB at 1MHz under specified conditions.

Key Specifications

Pinout & Package

MP8903DG-3.3-LF-P is housed in a thermally enhanced QFN8 package (2mm × 2mm, 0.5mm pitch) with exposed thermal pad. The 8-pin layout supports compact routing and efficient heat dissipation into PCB copper planes.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar low-dropout linear regulator applications.

Compared with MCP1700-3302E/TO and XC6206P332MR-G, MP8903DG-3.3-LF-P delivers lower dropout (100mV vs. ≥160mV), integrated EN control, and robust thermal shutdown - making it preferable for portable, thermally constrained, or sequenced power systems.

Availability

MP8903DG-3.3-LF-P is available at Aetrix Electronics and suitable for mobile handset PLL power, audio codec supply, and 802.11 PC card applications requiring stable component supply, RoHS-compliant packaging, and QFN8 thermal performance.

Supply support for MP8903DG-3.3-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 in the US, China, and Taiwan.

The MP8903 belongs to MPS's low-power LDO product line, engineered for ultra-small footprint, low-noise operation, and thermal resilience in portable and battery-powered systems.

FAQ

What is the minimum input voltage required to maintain 3.3V output at 150mA?

The MP8903DG-3.3-LF-P requires VIN ≥ VOUT + VDROPOUT. At 150mA, typical dropout is 125mV (per datasheet Fig. 4), so minimum VIN is 3.425V. For guaranteed regulation across temperature and process variation, design for ≥3.45V input at full load.

Can the MP8903DG-3.3-LF-P be used in adjustable mode?

Yes - though configured as 3.3V fixed, the FB pin is accessible. Replace the internal divider by connecting an external R1/R2 network between OUT and FB, setting VOUT = 1.222V × (1 + R1/R2). Total resistance must stay ≤100kΩ for accuracy.

Is the exposed thermal pad electrically connected?

Yes - the exposed pad on the QFN8 package is internally connected to GND. It must be soldered to a PCB thermal pad tied to the main ground plane to achieve θJA = 80°C/W and enable full 150mA operation.

What is the maximum allowable EN pin voltage?

The EN pin absolute maximum rating is +6V. However, its logic thresholds are defined at VEN_H ≥ 1.5V and VEN_L ≤ 0.4V. Driving EN above 5.5V risks overstress; use clamping or level-shifting for 5V-tolerant microcontroller GPIO.

Does the MP8903DG-3.3-LF-P require an input capacitor?

Yes - a minimum 1µF X5R/X7R ceramic capacitor must be placed between IN and GND, within 2mm of the pins. This stabilizes input impedance, reduces high-frequency noise coupling, and improves line transient response per datasheet Section 6.

How does thermal shutdown behave during overload?

When junction temperature reaches 155°C, the device shuts down output and disables the pass transistor. After cooling by ≥30°C (to ≤125°C), it automatically resumes regulation - no manual reset or power cycle is needed.

What is the recommended output capacitor ESR range?

The MP8903DG-3.3-LF-P is stable with ceramic capacitors having ESR < 100mΩ. X5R/X7R types from 1µF to 10µF are validated; avoid high-ESR electrolytics or Y5V ceramics whose capacitance degrades significantly with DC bias and temperature.