Monolithic Power Systems Inc. MPQ1542DK-LF-P

Overview

MPQ1542DK-LF-P from Monolithic Power Systems is a current-mode, pin-selectable 700 kHz / 1.3 MHz step-up DC/DC converter with an integrated 2 A, 0.18 Ω, 25 V N-channel MOSFET switch. It operates from 2.5 V to 22 V input and delivers up to 12 V at 500 mA from a 5 V supply, supporting LCD bias rails and portable power rails requiring fast transient response and low-noise regulation.

For engineers reviewing the MPQ1542DK-LF-P datasheet, MPQ1542DK-LF-P pinout, MPQ1542DK-LF-P application, or MPQ1542DK-LF-P equivalent, key selection criteria include programmable soft-start timing, external compensation for ceramic-capacitor stability, dual-frequency selection (700 kHz / 1.3 MHz), UVLO hysteresis of 100 mV, and thermal shutdown at 160 °C - all critical for compact, high-efficiency boost designs in space-constrained applications.

Technical Context

The MPQ1542DK-LF-P implements constant-frequency peak-current mode control with internal current sensing and a transconductance error amplifier (350 μA/V, 1000 V/V gain). Its architecture enables stable regulation across wide input/output ranges while supporting fast load-step response via adjustable loop dynamics through the COMP pin.

It features dual fixed-frequency operation selected by FSEL pin logic (GND = 700 kHz, VIN = 1.3 MHz), programmable soft-start via external capacitor on SS pin (charged at 6 μA), and feedback regulation referenced to a precise 1.25 V ±2.5% FB threshold - enabling accurate output voltage setting with resistor dividers.

Key Specifications

Pinout & Package

The MPQ1542DK-LF-P is housed in an 8-pin MSOP package (3.0 mm × 3.0 mm × 1.0 mm height) with exposed thermal pad for enhanced thermal performance in high-power-density layouts.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar boost converter applications.

Compared with TPS61088RHLR and RT8535GJ6, the MPQ1542DK-LF-P uniquely balances programmability (FSEL, SS, COMP), thermal robustness (160 °C shutdown), and compact MSOP-8 packaging - making it optimal for space-constrained, multi-rail portable systems demanding both flexibility and reliability.

Availability

MPQ1542DK-LF-P is available at Aetrix Electronics and suitable for LCD display bias supplies, portable medical instrumentation, handheld industrial scanners, and digital camera power management requiring stable component supply and long-term production continuity.

Supply support for MPQ1542DK-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 over two decades of leadership in DC/DC conversion, motor drivers, and LED lighting controllers.

The MPQ1542 belongs to MPS's high-efficiency, current-mode boost converter product line, designed specifically for compact, low-noise, battery-powered applications requiring wide input range, fast transient response, and minimal external components.

FAQ

What is the maximum achievable output voltage with MPQ1542DK-LF-P?

The absolute maximum output voltage is 22 V, as defined by the SW pin rating and internal MOSFET breakdown voltage. In practice, stable operation up to 18 V is confirmed across temperature with proper compensation and thermal management. Output voltages above 15 V require careful attention to PCB layout, output capacitor voltage rating, and diode reverse voltage specification.

Can MPQ1542DK-LF-P operate in discontinuous conduction mode (DCM)?

Yes - the MPQ1542DK-LF-P naturally transitions into DCM at light loads due to its peak-current mode architecture and lack of forced continuous mode control. This improves light-load efficiency but introduces a right-half-plane zero; compensation must account for RHPZ location, especially below 20% of full load.

Is the 0.18 Ω R_DS(on) specified at 25 °C or over temperature?

The 0.18 Ω typical R_DS(on) is measured at T_J = 25 °C. At 125 °C junction temperature, R_DS(on) increases to approximately 0.26 Ω (based on silicon temperature coefficient). Designers should use the max value of 0.22 Ω (guaranteed over -40°C to +125°C) for worst-case power loss calculations.

How does the FSEL pin behave when left floating?

The FSEL pin has no internal pull-up or pull-down and must not be left floating. An unconnected FSEL may cause unpredictable frequency selection or increased quiescent current. For 700 kHz operation, tie FSEL directly to GND; for 1.3 MHz, connect via 100 kΩ resistor to IN (if VIN > 6 V) or directly to IN (if VIN ≤ 6 V).

What is the minimum recommended output capacitance for stable operation?

A minimum of 4.7 µF ceramic capacitance is required for stable regulation at 1.3 MHz, per MPS application guidance. Lower values risk instability or excessive ripple; larger values (e.g., 10–22 µF) improve transient response and reduce output voltage deviation during load steps.

Does MPQ1542DK-LF-P support synchronous rectification?

No - the MPQ1542DK-LF-P uses an external Schottky diode for asynchronous rectification. It does not integrate a second MOSFET or provide gate drive signals for synchronous operation. Synchronous boost alternatives (e.g., MPQ4332) require different pinouts and compensation approaches.

How is thermal performance affected by the MSOP-8 exposed pad?

The exposed thermal pad (Pin 4 extension) reduces θ_JA from 150 °C/W (no pad) to ~65 °C/W when soldered to ≥2 cm² of 2-oz copper with ≥4 thermal vias. Omitting pad connection degrades thermal resistance by >100%, risking premature thermal shutdown at >350 mW dissipation.