Monolithic Power Systems Inc. MP24971DS-LF

Overview

MP24971DS-LF from Monolithic Power Systems is a monolithic 5V/1.5A fixed-output step-down DC-DC converter with programmable current limit and output line-drop compensation. It operates across an 8V–50V input range, integrates a 0.4Ω internal MOSFET, and delivers stable regulation with 100kHz switching frequency and 2ms–4ms soft-start. Used in automotive power adapters and USB supplies where wide VIN and load-line compensation are critical.

For engineers reviewing the MP24971DS-LF datasheet, MP24971DS-LF pinout, MP24971DS-LF application, or MP24971DS-LF equivalent, key selection criteria include its 50V absolute max input rating, hiccup-mode current limiting, 6V over-voltage protection threshold, and SOIC8 package thermal performance (θJA = 90°C/W).

Technical Context

The MP24971DS-LF implements current-mode control with a 100kHz oscillator and integrated PWM comparator that compares error amplifier output against current-sense voltage plus slope compensation. Its internal 800mV reference and VOS feedback path enable precise 5V regulation independent of trace resistance when paired with VOC-based line-drop compensation.

Protection architecture includes hiccup-mode current limiting triggered at 100mV sense differential, output over-voltage shutdown at 6V (VOVP), and thermal shutdown at 150°C. The device uses an internal bootstrap regulator for high-side gate drive and supports external diode-assisted bootstrapping for high-duty-cycle operation.

Key Specifications

Pinout & Package

MP24971DS-LF is housed in a standard SOIC8 (Small Outline Integrated Circuit, 8-pin) package with exposed pad not present - distinct from the SOIC8E variant. Thermal resistance is θ_JA = 90°C/W and θ_JC = 45°C/W on a 4-layer PCB per JESD51-7. Pin 2 is GND (non-exposed pad); no thermal pad solder connection required.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar fixed-output buck converter applications.

Compared with LM5164QDDARQ1 and TPS54202DRCT, MP24971DS-LF uniquely combines 50V operation, factory-fixed 5V output, programmable current limit, and integrated line-drop compensation - reducing BOM count and improving load-side voltage accuracy in long-trace deployments.

Availability

MP24971DS-LF is available at Aetrix Electronics and suitable for automotive power adapters, USB-C peripheral supplies, and industrial linear charger interfaces requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for MP24971DS-LF 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 core expertise in DC-DC conversion, motor drivers, and LED lighting controllers.

The MP24971 belongs to MPS's industrial-grade buck converter product line, designed specifically for rugged 5V power delivery in automotive, transportation, and industrial equipment where input voltage variation and trace resistance are dominant design constraints.

FAQ

What is the maximum allowable input voltage for MP24971DS-LF?

The absolute maximum input voltage is 60V, but the recommended operating range is 8V to 50V. Operation above 50V risks exceeding internal MOSFET breakdown limits and may trigger over-voltage stress conditions not covered by warranty. The 50V upper limit ensures reliable 1.5A output with margin for transients.

Can MP24971DS-LF operate without an external sense resistor?

Yes - the device functions with R_SENSE = 0Ω, delivering up to 1.5A based on internal current-limit threshold. However, external R_SENSE (e.g., 66mΩ) is required to achieve precise 1.5A limiting and enable line-drop compensation via VOC. Omitting R_SENSE disables hiccup-mode short-circuit protection.

How does the VOC pin implement line-drop compensation?

VOC accepts a resistor-to-GND that sets gain for load-current-proportional voltage injection into the feedback path. With RTOP = 300kΩ and R_SENSE = 66mΩ, selecting R_C per R_C = (6 × R_SENSE × 300kΩ)/R_TRACE cancels trace IR drop - maintaining constant 5V at the load regardless of current draw.

Is an external bootstrap diode required for MP24971DS-LF?

No - the internal bootstrap regulator suffices for most applications. An external diode (e.g., BAT54) is only recommended when duty cycle exceeds 65% (e.g., VIN > 7.5V with 5V output), to ensure sufficient gate drive voltage and prevent high-side MOSFET dropout during continuous conduction mode.

What thermal derating applies to MP24971DS-LF in SOIC8 package?

At 25°C ambient, max continuous power dissipation is 1.38W. Above 25°C, derate linearly at 11.1 mW/°C (1/θ_JA). At 85°C ambient, usable power drops to ~0.72W - limiting practical 1.5A output to cases with forced airflow or low thermal resistance PCB layout.

Does MP24971DS-LF support synchronization to an external clock?

No - the MP24971DS-LF uses a fixed internal 100kHz oscillator with no SYNC pin or frequency adjustment capability. For synchronized multi-rail systems, consider MPS's MPQ4470 or external clocking-compatible alternatives.

What is the purpose of the VOS and VOC pins working together?

VOS provides direct feedback of output voltage to the error amplifier, while VOC injects a current-proportional correction signal into the same node. Together, they enable the regulator to dynamically raise VOUT setpoint as load current increases - counteracting IR drop across PCB traces and connectors to hold constant voltage at the load.