Monolithic Power Systems Inc. MP2145GD-P

Overview

MP2145GD-P from Monolithic Power Systems is a synchronous step-down DC/DC converter IC with integrated 20mΩ high-side and 12mΩ low-side MOSFETs, delivering up to 6A continuous output current from a 2.8V–5.5V input. It features constant-on-time (COT) control, 1.2MHz fixed switching frequency, 40μA quiescent current, and 0.6V adjustable output voltage-optimized for FPGA, SSD, and portable instrument power rails.

For engineers reviewing the MP2145GD-P datasheet, MP2145GD-P pinout, MP2145GD-P application, or MP2145GD-P equivalent, key selection criteria include its COT architecture for fast transient response, 100% duty cycle capability in dropout, ±1% feedback accuracy, and QFN-12 (2mm×3mm) thermal performance with θJA = 70°C/W.

Technical Context

The MP2145GD-P employs input-voltage feed-forward constant-on-time control to maintain stable 1.2MHz switching across its full 2.8V–5.5V input range and 0.6V–5.5V output range. Its internal high-side and low-side MOSFETs enable efficient 6A operation without external switches.

It integrates cycle-by-cycle overcurrent protection, hiccup-mode short-circuit recovery, thermal shutdown at 150°C, and a programmable MODE/VCON pin supporting both PWM/PPM mode selection and analog dynamic output voltage regulation via 0.6V–1.1V input.

Key Specifications

Pinout & Package

MP2145GD-P is housed in a thermally enhanced QFN-12 package (2mm × 3mm, 0.5mm pitch) with exposed thermal pad (Pin 10–12 and EP). The package supports high-current routing and achieves θJA = 70°C/W on standard 4-layer PCBs.

Key Features

Applications

Equivalent & Alternatives

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

Compared with RTQ2131B-QT and TPS546B24A, MP2145GD-P uniquely balances 6A capability, ultra-low IQ, analog VCON programmability, and minimal external component count in a 2mm×3mm footprint-making it optimal for space-constrained, battery-aware, and dynamically regulated embedded systems.

Availability

MP2145GD-P is available at Aetrix Electronics and suitable for SSD power management, FPGA core supplies, and portable instrumentation requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for MP2145GD-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 MP2145 belongs to MPS's high-efficiency, high-density DC/DC converter product line, engineered specifically for compact, battery-conscious, and thermally constrained applications in storage, computing, and portable electronics.

FAQ

What is the minimum recommended output capacitance for stable operation?

The MP2145GD-P is optimized for use with two 22µF X5R/X7R ceramic capacitors (44µF total) at the output. This value ensures stable CCM/DCM transition, limits output ripple to <15mV under 6A step load, and avoids light-load pulse-skipping instability. Larger values may induce sleep-mode oscillation in ultra-light loads.

Does MP2145GD-P support forced PWM mode across all load conditions?

Yes-driving the MODE/VCON pin to ≥1.2V forces continuous PWM operation regardless of load, eliminating frequency variation and minimizing output voltage ripple. This is essential for noise-sensitive analog circuits but increases light-load IQ to ~60µA versus 40µA in auto-PFM mode.

How does the internal 1.5ms soft-start interact with pre-biased outputs?

The MP2145GD-P monitors FB voltage versus internal soft-start ramp. If FB > SS voltage at power-on, the high-side and low-side MOSFETs remain off until SS crosses FB-preventing reverse current flow and ensuring monotonic startup into pre-charged rails without external circuitry.

Can the RAMP pin be left unconnected in standard applications?

Yes-the RAMP pin is optional and may be left floating in most designs. MPS confirms internal compensation is optimized for standard 0.47µH inductors and 22µF ceramic outputs. Only add an external RC network if load transient response exceeds specification or EMI filtering requires additional slope control.

What is the maximum allowable junction temperature during continuous 6A operation?

The absolute maximum junction temperature is 150°C, with thermal shutdown activating at that threshold and 20°C hysteresis. At TA = 85°C and 6A load, the QFN-12 package's θJA = 70°C/W yields ~129°C junction temperature-within safe operating margin when using recommended PCB copper area and airflow.

Is the PG pin compatible with 1.8V logic systems?

No-the PG pin is open-drain with internal 500kΩ pull-up to VIN (2.8–5.5V), so its HIGH state is VIN-referenced. To interface with 1.8V logic, a level-shifting resistor divider or buffer is required; direct connection risks overvoltage damage to downstream 1.8V GPIOs.

How does the output discharge function operate during disable?

When EN is pulled low, the MP2145GD-P activates an internal NMOS sink between OUT and GND, discharging the output capacitor through a controlled 100Ω path. This ensures rapid, predictable VOUT decay (<5ms for 22µF @ 1.2V) without external bleeder resistors or risk of backfeed.