Monolithic Power Systems Inc. MPQ8903DJ-2.85-LF-P

Overview

MPQ8903DJ-2.85-LF-P from Monolithic Power Systems is a fixed-output 2.85V, 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 - deployed in mobile handset PLL power rails and audio codec supplies.

For engineers reviewing the MPQ8903DJ-2.85-LF-P datasheet, MPQ8903DJ-2.85-LF-P pinout, MPQ8903DJ-2.85-LF-P application, or MPQ8903DJ-2.85-LF-P equivalent, key selection criteria include guaranteed –40°C to +85°C operation, TSOT23-5 package compatibility, EN-controlled sequencing, FB-adjustable capability (1.25V–5V), and thermal hysteresis of 30°C for robust system-level power integrity.

Technical Context

The MPQ8903DJ-2.85-LF-P employs 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, supporting both fixed (2.85V) and adjustable configurations using external resistive dividers.

Thermal protection activates at 155°C junction temperature with 30°C hysteresis, and the device maintains stability with 1µF–10µF X5R/X7R ceramic output capacitors. Input line regulation is 0.005–0.11%/V and load regulation is 0.001–0.03%/mA across industrial temperature range.

Key Specifications

Pinout & Package

MPQ8903DJ-2.85-LF-P is housed in a 5-pin TSOT23-5 package (0.95mm pitch, 2.9mm × 1.6mm footprint), optimized for space-constrained industrial and portable applications with exposed thermal pad not present in this variant.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MCP1700T-2852E/TT and TLS850F2BTV50, the MPQ8903DJ-2.85-LF-P uniquely balances industrial temperature assurance, EN controllability, and thermal hysteresis in a minimal 5-pin footprint - making it optimal for cost-sensitive, thermally constrained portable and embedded systems without automotive requirements.

Availability

MPQ8903DJ-2.85-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-2.85-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 interface applications.

The MPQ8903 belongs to MPS's industrial-grade linear regulator product line, designed specifically for reliable, low-noise voltage regulation in thermally demanding environments where precision, small size, and robust protection are mandatory.

FAQ

What is the maximum allowable input voltage for MPQ8903DJ-2.85-LF-P?

The absolute maximum input voltage is +7.0V, but continuous operation must remain within the recommended 2.7V to 6.5V range. Exceeding 6.5V risks permanent damage even briefly, and operation above 7.0V violates absolute maximum ratings and may cause immediate failure.

Can MPQ8903DJ-2.85-LF-P be used in adjustable mode despite its fixed 2.85V marking?

Yes - the FB pin supports adjustable configuration from 1.25V to 5V using an external resistor divider. The internal 2.85V setting results from factory-trimmed resistors; connecting R1 and R2 between OUT and FB overrides this, provided R1 + R2 ≤ 100kΩ to avoid loading the reference.

Does MPQ8903DJ-2.85-LF-P require an output capacitor, and what type is recommended?

Yes - a minimum 2.2µF X5R or X7R ceramic capacitor is required between OUT and GND for stability. Larger values up to 10µF improve load transient response. Tantalum or aluminum electrolytic capacitors are not recommended due to ESR and temperature-dependent capacitance drift.

How does the EN pin function, and what happens when left floating?

The EN pin is active-high with VIH ≥1.5V and VIL ≤0.4V. It must never be left floating: unconnected EN defaults to undefined state and may cause erratic startup or latch-up. For automatic enable, connect EN directly to IN; for controlled sequencing, drive from a logic source with defined voltage levels.

What thermal resistance values apply to the TSOT23-5 package under standard PCB conditions?

θJA is 220°C/W and θJC is 110°C/W, measured per JESD51-7 on a 4-layer PCB. These values assume proper copper pour under the package and adequate thermal vias. Without thermal relief, power dissipation is limited to ~250mW at +25°C ambient before thermal shutdown triggers.

Is MPQ8903DJ-2.85-LF-P RoHS compliant and halogen-free?

Yes - the "-LF" suffix explicitly denotes lead-free and RoHS-compliant packaging. Per MPS documentation, the device meets JEDEC JS709C and IPC-1752A requirements for halogen-free materials (Cl ≤ 900 ppm, Br ≤ 900 ppm).

What is the significance of the 30°C thermal hysteresis specification?

The 30°C hysteresis ensures the device remains off until junction temperature drops to 125°C (155°C – 30°C) after thermal shutdown. This prevents rapid cycling during marginal thermal conditions and extends long-term reliability in enclosed or convection-limited environments.