Monolithic Power Systems Inc. MP2918GL-P

Overview

MP2918GL-P from Monolithic Power Systems is a 4V–40V input, current-mode, synchronous step-down controller IC that drives dual N-channel MOSFETs to regulate output voltage in high-voltage DC/DC conversion. It features 0.8V ±1.5% reference accuracy, programmable 100–1000kHz switching frequency, and Advanced Asynchronous Mode (AAM) for light-load efficiency optimization. Used in automotive cold-crank and industrial power supplies where wide VIN and robust OVP/OCP protection are required.

For engineers reviewing the MP2918GL-P datasheet, MP2918GL-P pinout, MP2918GL-P application, or MP2918GL-P equivalent, key selection considerations include its dual-gate drive capability, 99.5% max duty cycle for low-dropout operation, 75mV current-limit threshold option, thermal shutdown at 170°C, and compatibility with external sync clocks up to 1MHz.

Technical Context

The MP2918GL-P implements peak-current-mode control with slope compensation, using an internal 0.8V reference and error amplifier output on COMP to modulate PWM duty cycle. Its cycle-by-cycle current limit is set by ILIM pin configuration (SGND/VCC1/floating), yielding fixed sense thresholds of 25mV/50mV/75mV respectively.

It supports two operating modes: forced CCM (via floating or VCC1-connected CCM/AAM) and AAM (via SGND-biased CCM/AAM), where switching frequency becomes variable and tied to COMP crossing VAAM. The 180° out-of-phase SYNCO output enables interleaved dual-channel designs without external phase-shift circuitry.

Key Specifications

Pinout & Package

MP2918GL-P is packaged in QFN-20 (3mm × 4mm) with exposed thermal pad. Pin numbering follows standard QFN top-view layout; exposed pad must be connected to both SGND and PGND for optimal thermal performance and noise isolation.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LM5116PWPR and TPS40210DGQR, MP2918GL-P uniquely combines 4V–40V operation, AAM light-load optimization, external sync capability, and integrated PG/SS functions-making it optimal for automotive and industrial applications demanding efficiency across full load range and robust system monitoring.

Availability

MP2918GL-P is available at Aetrix Electronics and suitable for automotive power supplies, industrial motor drives, telecom base stations, and railway signaling systems requiring stable component supply across extended temperature and voltage ranges.

Supply support for MP2918GL-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.

The MP2918 product line delivers high-voltage synchronous buck controllers optimized for automotive and industrial applications requiring wide input range, high efficiency across load conditions, and comprehensive protection features.

FAQ

What is the maximum allowable input voltage for continuous operation?

The MP2918GL-P is rated for continuous operation up to 40V input. Its absolute maximum rating is 65V, but sustained operation above 40V risks damage or premature failure. The internal UVLO rising threshold is 4.5V, and falling threshold is 3.7V, ensuring reliable startup and shutdown within the specified range.

How does the ILIM pin configure current limit thresholds?

The ILIM pin selects one of three fixed current-sense voltage thresholds: 25mV (ILIM = SGND), 50mV (ILIM = VCC1), or 75mV (ILIM = floating). These correspond to peak inductor current limits determined by the external sense resistor value. No external DAC or resistor divider is needed-only a direct connection or open circuit.

Can MP2918GL-P operate without an external VCC2 supply?

Yes. When VCC2 is unconnected or below 4.7V, the internal VCC1 regulator derives power from VIN. A ≥1µF ceramic capacitor between VCC1 and PGND is mandatory. Using VCC2 (4.7V–12V) improves efficiency by reducing VIN-derived dissipation, especially in high-input-voltage applications.

What is the purpose of the SYNCO pin in multi-phase designs?

The SYNCO pin outputs a 180° out-of-phase clock signal synchronized to the internal oscillator. In dual-MP2918 configurations, connecting SYNCO from one device to EN/SYNC of the second enables interleaved operation, halving input/output ripple current and improving thermal distribution across phases.

Does MP2918GL-P support forced continuous conduction mode (CCM)?

Yes. Connecting the CCM/AAM pin to VCC1 or leaving it floating forces CCM operation. This ensures constant switching frequency regardless of load, simplifying EMI filtering and loop compensation. AAM is only active when CCM/AAM is pulled low (≤480mV) via an external resistor to SGND.

How is power-good (PG) timing defined during startup and fault conditions?

PG asserts high after a 37µs delay once VOUT reaches 90% of target; it pulls low within 28µs if VOUT falls below 87% of target. During OVP, PG remains high until VOUT recovers, while hiccup-mode OCP causes PG to toggle with restart cycles. PG is open-drain and requires an external pull-up resistor (e.g., 100kΩ to ≤5V).

What thermal considerations apply to the QFN-20 (3mm×4mm) package?

The QFN-20 package has θJA = 48°C/W and θJC = 10°C/W. For reliable operation at full load, the exposed thermal pad must be soldered to a PCB copper area connected to both SGND and PGND. Thermal vias under the pad (≥6×0.3mm) are recommended to transfer heat to inner layers or heatsink planes.