Monolithic Power Systems Inc. MP24971DS-LF-Z

Overview

MP24971DS-LF-Z from Monolithic Power Systems is a monolithic 5V fixed-output, 1.5A continuous step-down DC/DC converter with programmable current limit and output line-drop compensation. It operates across an 8V–50V input range, features a 0.4Ω internal MOSFET, fixed 100kHz switching frequency, and integrated hiccup-mode over-current protection. It is used in automotive power adapters where stable 5V rail generation under varying load-line conditions is required.

For engineers reviewing the MP24971DS-LF-Z datasheet, MP24971DS-LF-Z pinout, MP24971DS-LF-Z application, or MP24971DS-LF-Z equivalent, key selection criteria include its 5V fixed output regulation, 50V absolute max input rating, SOIC8 package thermal performance (θJA = 90°C/W), and VOC-based line-drop compensation capability for remote load regulation.

Technical Context

The MP24971DS-LF-Z implements a current-mode buck architecture with internal 100kHz oscillator and 800mV reference error amplifier. Its peak-current sensing uses ISP/ISN differential inputs with 100mV threshold, enabling precise 1.5A current limiting and short-circuit hiccup recovery.

It integrates output voltage sense (VOS) feedback, bootstrap gate drive (BST/SW), and VOC pin-based load-line compensation-where external RC network sets gain to offset trace resistance-induced voltage drop at the load. Thermal shutdown activates at 150°C with automatic recovery.

Key Specifications

Pinout & Package

MP24971DS-LF-Z is housed in an 8-pin SOIC package (JEDEC MS-012 AA) with exposed pad not connected internally; thermal performance relies on PCB copper area under Pin 2 (GND). Package dimensions: 4.90mm × 6.00mm × 1.75mm (L×W×H).

Key Features

Applications

Equivalent & Alternatives

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

Compared with MP24971DS-LF-Z, MP24943DJ-LF-Z offers better thermal headroom but forfeits load-point voltage accuracy, while LM5164QDDARQ1 adds automotive qualification at the cost of integration and compensation flexibility.

Availability

MP24971DS-LF-Z is available at Aetrix Electronics and suitable for USB power supplies, automotive power adapters, and industrial IoT sensor nodes requiring stable component supply with full RoHS-compliant packaging and tape-and-reel delivery.

Supply support for MP24971DS-LF-Z 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 MP24971 belongs to MPS's high-voltage buck converter product line, designed specifically for robust 5V rail generation in automotive, industrial, and USB power applications where input transients and trace resistance challenge regulation accuracy.

FAQ

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

The absolute maximum input voltage is 60V, but the recommended operating range is 8V to 50V. Exceeding 50V may trigger internal over-voltage protection or cause reliability degradation. The 50V rating ensures compatibility with 48V industrial systems and automotive load-dump events.

How does the VOC pin enable output line-drop compensation?

The VOC pin accepts a resistor-to-ground that sets gain for the load-line compensation amplifier. When load current flows through PCB trace resistance, the resulting voltage drop is offset by adjusting the feedback reference-ensuring 5V remains stable at the remote load, not just at the IC's VOS pin.

Can MP24971DS-LF-Z operate without an external sense resistor?

Yes-it supports inductor DCR sensing (Figure 3a) using Ra/Ca filter, eliminating R_SENSE. However, the default 1.5A current limit assumes 66mΩ R_SENSE; DCR sensing requires careful inductor selection and calibration to match 100mV threshold accuracy.

What thermal derating applies to the SOIC8 package at 85°C ambient?

With θJA = 90°C/W and T_J(MAX) = 125°C, maximum continuous power dissipation at 85°C ambient is 444mW. At 1.5A output and 5V, this corresponds to ~12V minimum input to stay within thermal limits-higher input voltages require reduced load current or enhanced PCB copper.

Is the BST pin required to be connected externally?

Yes-a 0.1µF ceramic capacitor must connect between BST and SW pins to form the floating gate-drive supply. An external Schottky diode from VIN or VOUT to BST is optional but recommended for duty cycles above 65% to ensure reliable high-side gate turn-on.

Does MP24971DS-LF-Z support synchronization to an external clock?

No-it uses an internal fixed-frequency 100kHz oscillator with no SYNC pin or frequency-adjust capability. For synchronized multi-rail systems, consider MP2494x series or discrete oscillator injection methods, though unsupported in this variant.

What failure modes trigger hiccup-mode protection?

Hiccup mode activates during sustained over-current (e.g., shorted output), over-temperature (>150°C), or output over-voltage (>6V at ISN). The device disables SW, waits for VOS to fall below 1.9V and VCOMP to rise above 3V, then restarts soft-start-repeating until fault clears.