Monolithic Power Systems Inc. MP3115DT-LF-Z

Overview

MP3115DT-LF-Z from Monolithic Power Systems is a synchronous, fixed-frequency (1.3 MHz), current-mode step-up DC-DC converter optimized for single-cell alkaline battery input (0.95 V startup) to regulated 2.5 V or 3.3 V output at up to 200 mA. It integrates P- and N-channel MOSFETs, provides output-to-input disconnect in shutdown (<1 µA IQ), and eliminates external Schottky diodes. Used in compact portable audio and wireless peripherals.

For engineers reviewing the MP3115DT-LF-Z datasheet, MP3115DT-LF-Z pinout, MP3115DT-LF-Z application, or MP3115DT-LF-Z equivalent, key selection criteria include minimum startup voltage (0.95 V), integrated synchronous rectification (R_PMOS = 600 mΩ, R_NMOS = 300 mΩ), output disconnect capability, thermal shutdown (160 °C), and SOT23-6 package compatibility with space-constrained designs.

Technical Context

The MP3115 employs a fixed 1.3 MHz current-mode control architecture with internal compensation and soft-start, enabling stable regulation across wide load and input ranges. Its dual-MOSFET topology-N-channel switch and P-channel synchronous rectifier-enables high efficiency (>90%) and true output disconnect by breaking the SW–OUT path when disabled.

Startup occurs down to 0.95 V input with inrush limiting; regulation uses a 1.225 V feedback reference and external resistive divider. Thermal shutdown (160 °C, 30 °C hysteresis) and peak current limit (1 A min) provide robust protection under fault conditions without external components.

Key Specifications

Pinout & Package

SOT23-6 package: 2.9 mm × 1.6 mm × 1.1 mm body, 0.95 mm pitch, thermally enhanced pad-less footprint compatible with standard reflow profiles.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MP3414DT-LF-Z, the MP3115DT-LF-Z offers proven reliability in mature consumer designs but lacks newer features like sub-1 V startup and 2 MHz operation; versus TPS61200DRCR, it delivers superior integration (no diode, disconnect) and smaller total solution area despite identical package footprint.

Availability

MP3115DT-LF-Z is available at Aetrix Electronics and suitable for wireless mouse power management, MP3 player battery boost, RFTag sensor node supply, and audio recorder low-voltage operation requiring stable component supply and long-term lifecycle support.

Supply support for MP3115DT-LF-Z 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 core expertise in DC-DC conversion, motor drivers, and LED lighting controllers.

The MP3115 belongs to MPS's high-efficiency, low-voltage boost converter product line, designed specifically for space- and energy-constrained portable electronics powered by primary batteries.

FAQ

What is the minimum input voltage required for MP3115DT-LF-Z to start switching?

The MP3115DT-LF-Z starts switching at a minimum input voltage of 0.95 V under typical conditions (RL = 3 kΩ, rising edge). This allows operation from nearly depleted alkaline cells. Startup behavior is guaranteed down to this voltage; operation below 0.95 V is not functional.

Does MP3115DT-LF-Z require an external Schottky diode?

No. The MP3115DT-LF-Z integrates both N-channel and P-channel MOSFETs to implement synchronous rectification, eliminating the need for an external Schottky diode. This reduces conduction losses, improves efficiency above 90%, and shrinks overall solution size.

How does the output disconnect feature work during shutdown?

When EN is pulled low (<0.4 V), both internal MOSFETs turn off and the P-channel body diode is reverse-biased, breaking the conductive path between OUT and IN. This isolates the output capacitor, allowing it to fully discharge and reducing shutdown current to <1 µA.

Can MP3115DT-LF-Z regulate 4.0 V output from a single AA cell?

Yes. The MP3115DT-LF-Z supports output voltages up to 4.0 V, set via the FB resistive divider. At 200 mA load and 1.5 V input, it maintains regulation at 4.0 V. Output accuracy depends on resistor tolerance and feedback reference (1.225 V ±1%).

What is the recommended inductor value for general-purpose use?

MPS recommends a 4.7 µH inductor for most applications. This value balances peak-to-peak ripple current (30–50% of max input current), size, and saturation margin. Inductor DCR should be minimized, and saturation current rating must exceed 1.3 A peak.

Is MP3115DT-LF-Z RoHS compliant and lead-free?

Yes. The "-LF" suffix indicates lead-free and RoHS-compliant packaging. The device meets JEDEC J-STD-020 moisture sensitivity level 1 and is qualified for standard reflow soldering processes without special handling.

What happens during thermal shutdown, and how does recovery work?

At 160 °C junction temperature, the MP3115DT-LF-Z disables both switches and halts switching. Recovery occurs only after temperature falls by ≥30 °C (to ≤130 °C), ensuring safe restart without thermal cycling. This behavior is guaranteed by design and tested in qualification.