Monolithic Power Systems Inc. MPQ8903DJ-2.5-LF-P

Overview

MPQ8903DJ-2.5-LF-P from Monolithic Power Systems is a fixed-output 2.5V, 150mA industrial-grade low-dropout linear regulator operating from 2.7V to 6.5V input, delivering ±2% output accuracy with 100mV dropout at 100mA, thermal shutdown protection, and stable operation with low-ESR ceramic capacitors in TSOT23-5 package - used for powering mobile handset PLLs and audio codecs.

For engineers reviewing the MPQ8903DJ-2.5-LF-P datasheet, MPQ8903DJ-2.5-LF-P pinout, MPQ8903DJ-2.5-LF-P application, or MPQ8903DJ-2.5-LF-P equivalent, key selection criteria include guaranteed –40°C to +85°C operation, FB reference voltage of 1.222V, EN-controlled enable/disable functionality, and compatibility with 1µF–10µF X5R/X7R input/output capacitors.

Technical Context

The MPQ8903DJ-2.5-LF-P uses a PMOS pass transistor architecture enabling low dropout performance and inherent reverse-current blocking. Its internal 1.222V bandgap reference feeds a precision error amplifier that regulates output via feedback from the FB pin.

Thermal protection activates at 155°C with 30°C hysteresis, and the EN pin provides logic-level control (VIH ≥ 1.5V, VIL ≤ 0.4V) for sequencing or power gating. The device supports both fixed-output (2.5V variant) and adjustable configurations via external resistor divider on FB.

Key Specifications

Pinout & Package

MPQ8903DJ-2.5-LF-P is housed in a 5-pin TSOT23 package (2.9mm × 1.6mm × 0.9mm), optimized for space-constrained industrial and portable applications. Thermal resistance θ_JA = 220°C/W on standard 4-layer PCB.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MCP1703T-2502E/MB and TLS850B2LF33, the MPQ8903DJ-2.5-LF-P uniquely balances industrial temperature range, EN control, thermal hysteresis, and minimal external components - making it optimal for portable and embedded systems where sequencing, reliability, and board space are critical.

Availability

MPQ8903DJ-2.5-LF-P is available at Aetrix Electronics and suitable for mobile handset PLL power, audio codec bias supply, and industrial sensor signal conditioning requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for MPQ8903DJ-2.5-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, headquartered in Kirkland, Washington, with global design and support operations.

The MPQ8903 belongs to MPS's industrial-grade linear regulator product line, engineered for robustness in demanding environments - emphasizing thermal resilience, wide input range, and minimal external component count for space-constrained designs.

FAQ

What is the minimum input voltage required to maintain 2.5V output at full 150mA load?

The MPQ8903DJ-2.5-LF-P has a maximum dropout voltage of 150mV at 150mA (per electrical characteristics table). To sustain 2.5V output, VIN must be ≥ 2.65V. At 2.7V minimum rated input, it delivers full-rated current with margin across temperature and process variation.

Can the FB pin be left floating in the fixed-2.5V version?

Yes - the FB pin is internally connected to a precision resistor divider for fixed-output variants. Datasheet explicitly states FB "must remain unconnected" for fixed versions. Floating FB does not affect regulation or stability and avoids unintended voltage adjustment.

Does this regulator require an output capacitor, and what type is recommended?

Yes - a minimum 1µF X5R or X7R ceramic capacitor is required between OUT and GND for stability. Larger values up to 10µF improve load transient response. Other dielectrics (e.g., Y5V) are discouraged due to capacitance drift over temperature and bias.

How does the EN pin behave during power-up, and what is its leakage current?

EN is CMOS-compatible with VIH ≥ 1.5V and VIL ≤ 0.4V. Input bias current is ≤ 2µA over temperature. When left unconnected, internal pull-down ensures default OFF state - preventing unintended startup. For automatic enable, connect EN directly to IN.

Is thermal shutdown reversible, and what happens after it triggers?

Yes - thermal shutdown is fully reversible. When junction temperature exceeds 155°C, the regulator shuts down output. After cooling by ≥30°C (hysteresis), it automatically resumes regulation without external reset. This protects against latch-up and enables self-recovery in intermittent overload conditions.

What is the purpose of the feed-forward capacitor mentioned in the datasheet?

The optional feed-forward capacitor (CBYP) connects across R1 in adjustable configurations to improve transient response by injecting high-frequency error correction. It is not required for fixed-output use or basic stability - only beneficial for dynamic loads exceeding 100mA/µs slew rate.