Monolithic Power Systems Inc. MP2305DS-LF

Overview

MP2305DS-LF from Monolithic Power Systems is a monolithic synchronous buck regulator integrating 130mΩ high- and low-side N-channel MOSFETs, delivering 2A continuous output current across a 4.75V–23V input range with adjustable output from 0.923V to 20V. It employs fixed-frequency (340kHz) current-mode control, features programmable soft-start, cycle-by-cycle overcurrent protection, and operates in an 8-pin SOIC package-used in FPGA/DSP power supplies and notebook DC/DC conversion.

For engineers reviewing the MP2305DS-LF datasheet, MP2305DS-LF pinout, MP2305DS-LF application, or MP2305DS-LF equivalent, key selection criteria include its 2A load capability, integrated 130mΩ MOSFETs, 0.923V feedback reference, 340kHz switching frequency, and thermal shutdown at 160°C-critical for compact, high-efficiency point-of-load designs.

Technical Context

The MP2305DS-LF implements current-mode control with internal transconductance error amplifier (GEA = 800μA/V) and COMP pin-based loop compensation. Its functional block includes a 340kHz oscillator, cycle-by-cycle current sensing via GCS = 3.5A/V, and dual overvoltage protection: FB overvoltage comparator (trip at 1.1V) and EN lockout (2.2–2.7V).

It uses bootstrap gate drive architecture requiring a 0.01μF capacitor between SW and BS pins to enable high-side MOSFET operation above VIN. Input under-voltage lockout activates at 3.80–4.40V with 210mV hysteresis, and shutdown supply current is 1μA-enabling low-power standby in portable systems.

Key Specifications

Pinout & Package

MP2305DS-LF is housed in an 8-pin SOIC package (JEDEC MS-012, variation AA), with 1.27mm pitch, 3.9mm × 4.9mm body, and exposed pad not present. Thermal resistance θ_JA = 90°C/W on 4-layer PCB.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MP2305DS-LF, MP2314S offers higher current and input voltage headroom but requires board redesign; LM2678-ADJ trades integration for cost and thermal simplicity-making it viable only in non-space-constrained, low-efficiency applications.

Availability

MP2305DS-LF is available at Aetrix Electronics and suitable for FPGA power supplies, notebook auxiliary rails, networking ASIC biasing, and green appliance control modules requiring stable component supply and long-term industrial support.

Supply support for MP2305DS-LF 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 MP2300-series targets cost-sensitive, space-constrained DC/DC conversion in computing, networking, and consumer electronics-emphasizing integration, efficiency, and ease of use in single-layer or compact multilayer PCBs.

FAQ

Is MP2305DS-LF recommended for new designs?

No. Monolithic Power Systems explicitly states "NOT RECOMMENDED FOR NEW DESIGNS" and directs users to MP2314S as the functional successor. MP2305DS-LF remains available for legacy support and existing production, but new projects should evaluate MP2314S for improved specs and long-term supply assurance.

What is the minimum output voltage achievable with MP2305DS-LF?

The minimum regulated output voltage is 0.923V-the internal feedback reference voltage. This is set by the precision bandgap reference and cannot be lowered; output voltages below this require external circuitry and are unsupported by the control loop.

Can MP2305DS-LF operate with 24V input?

No. The absolute maximum input voltage is 26V, but the recommended operating maximum is 23V. Applying 24V exceeds specification limits and risks reliability degradation or immediate failure-especially under thermal stress or high duty cycle.

Why does MP2305DS-LF require a capacitor between SW and BS pins?

The BS pin supplies gate drive voltage for the high-side N-MOSFET, which must exceed VIN. The SW-to-BS capacitor forms a flying charge pump: when SW is low, the capacitor charges from the internal 5V rail; when SW is high, it boosts gate voltage above VIN to fully enhance the high-side switch.

Does MP2305DS-LF support remote sensing?

No. The FB pin senses voltage only at the IC's local feedback node. Remote sensing-measuring voltage at the load to compensate for PCB trace IR drop-is not supported; output regulation accuracy depends entirely on local FB divider placement and routing.

What is the purpose of the COMP pin, and how is it used?

COMP is the output node of the internal transconductance error amplifier. It connects to an external RC network (and optionally a second capacitor) to set loop gain, phase margin, and transient response-enabling stable regulation across varied output capacitance and ESR values without requiring external op-amps.

How does the EN pin behave during power-up?

The EN pin has a rising threshold of 1.1–2.0V and hysteresis of 210mV. With a 100kΩ pull-up resistor, it ensures reliable startup once input voltage reaches ~4.75V. Below threshold, the IC draws only 1μA; above, full operation begins after soft-start completes.