Monolithic Power Systems Inc. MP8718EN-LF-P

Overview

MP8718EN-LF-P from Monolithic Power Systems is a synchronous step-down DC/DC converter with integrated 120mΩ high-side and 20mΩ low-side MOSFETs, delivering 4A continuous output current across 4.5V–21V input range, fixed 500kHz switching frequency, and adjustable 0.8V–21V output voltage-used in notebook I/O power and flat-panel display bias rails.

For engineers reviewing the MP8718EN-LF-P datasheet, MP8718EN-LF-P pinout, MP8718EN-LF-P application, or MP8718EN-LF-P equivalent, key selection criteria include internal MOSFET R_DS(on), thermal shutdown at 150°C, EN/SYNC dual-function pin for enable control or external clock synchronization, and SOIC8E exposed-pad package for thermal management.

Technical Context

The MP8718EN-LF-P operates in peak-current-mode control with internal compensation, enabling fast transient response and stable regulation without external loop components. Its proprietary switching loss reduction technique and synchronous rectification deliver >92% efficiency at 4A load with 12V input and 1.2V output.

It integrates a 5V internal VCC regulator powered from VIN, bootstrap circuitry for high-side gate drive, and hiccup-mode overcurrent protection triggered when FB falls below 500mV-ensuring robust short-circuit recovery in distributed power systems.

Key Specifications

Pinout & Package

The MP8718EN-LF-P is housed in an 8-pin SOIC package with exposed thermal pad (SOIC8E), where the pad must be soldered to a GND copper plane using multiple vias for optimal thermal performance (θ_JA = 50°C/W).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar synchronous step-down converter applications.

Compared with RT7290BZSP and TPS544B20RVFT, the MP8718EN-LF-P uniquely combines SOIC8E thermal performance, SYNC functionality, and internal compensation-making it optimal for cost-sensitive, thermally constrained analog-rich designs where simplicity and reliability outweigh digital configurability.

Availability

MP8718EN-LF-P is available at Aetrix Electronics and suitable for notebook I/O power, flat panel display bias, and distributed telecom power requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for MP8718EN-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 in the US, China, and Taiwan, and global manufacturing partnerships.

The MP8718 belongs to MPS's high-efficiency DC/DC converter product line, engineered for compact, thermally robust point-of-load regulation in computing, consumer, and communications equipment where integrated MOSFETs and minimal external components are essential.

FAQ

What is the minimum recommended input capacitance for MP8718EN-LF-P?

A 22µF X5R/X7R ceramic capacitor is recommended at the IN pin, placed as close as possible to pins 1 and 8. For high-RMS current handling, use parallel 10µF + 10µF or add a 0.1µF ceramic directly at the IC for high-frequency decoupling. Electrolytic or tantalum types require a local 0.1µF ceramic bypass.

Can MP8718EN-LF-P operate with input voltage below 4.5V?

No. The absolute minimum operating input voltage is 4.5V per datasheet specifications. Below this, the internal VCC regulator cannot sustain 5V bias, causing erratic operation or shutdown. The UVLO rising threshold is 4.0V, but functional regulation begins only above 4.5V.

How is output voltage set, and what tolerance does the FB pin provide?

Output voltage is set using a resistor divider from VOUT to GND, with the midpoint connected to FB. The internal reference is 0.805V ±12mV (±1.5%), yielding ≤±1% total output error when using 0.5% resistors. For 1.2V output, typical values are R1 = 4.99kΩ and R2 = 10.2kΩ.

Does MP8718EN-LF-P require an external bootstrap diode?

An external bootstrap diode (e.g., IN4148) is optional and recommended only when duty cycle exceeds 65% (e.g., VOUT > 13.65V at VIN = 21V). It improves efficiency by reducing BST capacitor charging losses but is unnecessary for typical 1.2V–3.3V outputs.

What thermal derating applies above 25°C ambient?

With θ_JA = 50°C/W, maximum continuous output current decreases linearly above 25°C: I_OUT(T_A) = 4A × (1 − (T_A − 25)/75). At 85°C ambient, rated output drops to ~2.4A assuming no additional PCB copper area or airflow.

Is the EN/SYNC pin 5V-tolerant when used for external clock input?

Yes. When used as SYNC input, the EN/SYNC pin accepts 300kHz–2MHz square-wave clocks with 1.5V–5.5V amplitude and 50% ±15% duty cycle. It is not 5V-tolerant in enable mode-logic-high threshold is 1.3V, and absolute max rating is 6V.

What failure modes trigger hiccup mode versus immediate shutdown?

Hiccup mode activates only during sustained overcurrent events that cause FB voltage to fall below 500mV for >100µs-indicating output short or severe overload. Thermal shutdown (150°C) and UVLO (<4.0V VCC) cause immediate, non-restarting shutdown until fault clears.