Monolithic Power Systems Inc. MP38671DL-LF-P

Overview

MP38671DL-LF-P from Monolithic Power Systems is a monolithic synchronous step-down DC/DC converter with integrated 60 mΩ high-side MOSFET and external low-side gate driver, delivering 10 A continuous output current across 4.5–25 V input range, fixed 600 kHz switching frequency, and adjustable 0.8–15 V output voltage-used in flat-panel TV power rails and distributed point-of-load systems.

For engineers reviewing the MP38671DL-LF-P datasheet, MP38671DL-LF-P pinout, MP38671DL-LF-P application, or MP38671DL-LF-P equivalent, key selection criteria include its synchronizable clock interface (300 kHz–1.4 MHz), cycle-by-cycle overcurrent protection, thermal shutdown at 150°C, power-good indicator with 40 mV hysteresis, and QFN14 3×4 mm package with exposed thermal pad.

Technical Context

The MP38671 operates in fixed-frequency peak-current-mode control with internal 0.8 V reference and error amplifier driving COMP node for loop compensation. Its architecture integrates a high-side MOSFET switch and dedicated BG driver output to drive an external synchronous rectifier, enabling up to 95% efficiency.

Functional blocks include a 600 kHz oscillator synchronized via EN/SYNC pin, bootstrap charging circuit for floating gate drive, UVLO (4.1 V rising threshold), soft-start ramp (1–5 ms), and latch-off mode triggered by output undervoltage (<70% nominal) during sustained short-circuit faults.

Key Specifications

Pinout & Package

MP38671DL-LF-P is housed in a thermally enhanced 3 mm × 4 mm, 14-pin QFN package with exposed thermal pad soldered to PCB ground plane for optimal heat dissipation (θ_JA = 48°C/W).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar synchronous buck controller applications.

Compared with MPQ38671-AEC1, the MP38671DL-LF-P offers identical performance at lower cost and qualification overhead for industrial/consumer use; versus RT7295BGJ8F, it trades integrated low-side switching for higher current capability and design flexibility via external MOSFET selection.

Availability

MP38671DL-LF-P is available at Aetrix Electronics and suitable for flat panel television power rails, digital set-top box core supplies, and broadband communications equipment requiring stable component supply, RoHS-compliant packaging, and volume-ready lead times.

Supply support for MP38671DL-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 design centers across Asia and North America and global manufacturing partnerships.

The MP38671 belongs to MPS's high-current synchronous buck controller product line, engineered for compact, efficient point-of-load conversion in space-constrained consumer and industrial systems where thermal performance and reliability are critical.

FAQ

What is the minimum recommended output capacitance for stable operation?

The MP38671DL-LF-P is stable with low-ESR ceramic capacitors ≥22 µF, such as X5R/X7R types. For 3.3 V/10 A operation, a 47 µF/6.3 V X7R capacitor with ≤5 mΩ ESR meets ripple and stability requirements while supporting fast transient response without external compensation.

Can the MP38671DL-LF-P operate without an external synchronous MOSFET?

No-the MP38671DL-LF-P integrates only a high-side MOSFET and requires an external low-side MOSFET driven by the BG pin. Omitting the external FET disables synchronous rectification, causing excessive conduction loss and thermal failure under load; Schottky diode substitution is not supported.

How does the EN/SYNC pin function during clock synchronization?

When used for synchronization, the EN/SYNC pin accepts a CMOS-compatible external clock (300 kHz–1.4 MHz); the internal oscillator aligns its rising edge to the external clock's rising edge. During sync, the part remains enabled-EN functionality is retained only when external clock is absent or below 300 kHz.

What is the purpose of the N/C pin (Pin 7) and how should it be handled?

Pin 7 is internally unconnected and must remain electrically floating-no trace, pull-up, or pull-down is permitted. Routing a trace to this pin risks coupling noise into adjacent high-speed nodes (SW, BG) and violates MPS's validated layout guidelines for EMI and thermal performance.

Does the MP38671DL-LF-P support output voltages below 0.8 V?

No-the internal reference is fixed at 0.808 V, and the feedback network is designed for V_OUT ≥ 0.8 V. Attempting sub-0.8 V operation causes the error amplifier to saturate, disabling regulation; for lower outputs, a different controller with adjustable reference or external reference injection is required.

How is thermal performance affected by the exposed pad connection?

The exposed pad is electrically GND and thermally critical: incomplete soldering or undersized thermal vias increases θ_JA beyond 48°C/W, raising junction temperature by >20°C at 10 A. MPS specifies ≥9 thermal vias (0.3 mm diameter, filled) connecting pad directly to inner ground plane for rated performance.

What happens during a sustained output short-circuit condition?

Under sustained short, FB voltage collapses below 250 mV, triggering frequency foldback (to 150 kHz) and eventual output undervoltage detection. Once V_FB drops below 70% of nominal, the device enters latch-off mode-halting switching until EN is cycled or input power is removed.