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Home > Products > Integrated Circuits (ICs) > Power Management (PMIC) > Voltage Regulators - DC DC Switching Regulators

Monolithic Power Systems Inc. MP3120DJ-LF-P

Name: MP3120DJ-LF-P
Brand: Monolithic Power Systems Inc.
SKU: MP3120DJ-LF-P
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: MP3120DJ-LF-P

Manufacturer:: Monolithic Power Systems Inc.

Category:: Voltage Regulators - DC DC Switching Regulators

Package:: SOT-23-6 Thin, TSOT-23-6

Datasheet:: MP3120DJ-LF-P.pdf

Description:: IC REG BOOST ADJ 1.2A TSOT23-6

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Inventory:2,684

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Product details

Overview

MP3120DJ-LF-P from Monolithic Power Systems is a synchronous boost converter IC with 1.2A switch current, 1.1MHz fixed-frequency operation, and true output disconnect via integrated P-MOSFET. It starts up from 0.8V input, supports 2.5–5V adjustable output, and delivers up to 96% efficiency in portable battery-powered systems such as wireless mice and MP3 players.

For engineers reviewing the MP3120DJ-LF-P datasheet, MP3120DJ-LF-P pinout, MP3120DJ-LF-P application, or MP3120DJ-LF-P equivalent, key selection criteria include low-voltage startup capability, inrush current limiting, short-circuit protection, internal compensation, and TSOT23-6 package compatibility with space-constrained PCB layouts.

Technical Context

The MP3120DJ-LF-P implements current-mode PWM control with internal slope compensation and a transconductance error amplifier referenced to a 1.2V internal bandgap. Its dual-MOSFET architecture (N-MOS switch + P-MOS rectifier) enables bidirectional output disconnect and V_OUT regulation even when V_IN exceeds V_OUT.

Startup uses a dedicated oscillator enabling operation at 0.8V, transitioning to closed-loop PWM once V_OUT > 2.3V; thermal regulation reduces peak current above 125°C and triggers shutdown at 160°C. Soft-start time is 0.7–2.6ms, and switching frequency remains stable across load and input conditions (865–1155kHz).

Key Specifications

Parameter	Value and Actual Design Meaning
Switch Current Limit	1.2A typical - sets maximum inductor peak current for reliable overcurrent handling without external sensing
Feedback Voltage	1.2V ±0.04V - defines output voltage accuracy via resistor divider (V_OUT = 1.2V × [1 + R1/R2])
Startup Input Voltage	0.8V min - enables operation from deeply discharged single-cell alkaline or NiMH batteries
Quiescent Current (Shutdown)	<1µA - ensures near-zero battery drain during system sleep or disable states
Switching Frequency	1.1MHz nominal - permits use of compact 4.7µH inductors and 10µF ceramic capacitors
N-MOS On Resistance	290mΩ max - minimizes conduction loss during boost phase under full load
P-MOS On Resistance	530mΩ max - limits dropout and power dissipation during output disconnect and V_IN > V_OUT mode

Pinout & Package

MP3120DJ-LF-P is housed in a 6-lead TSOT23-6 (Thin Small Outline Transistor) package with exposed pad for thermal enhancement. Pin spacing is 0.95mm, body dimensions are 2.9mm × 1.6mm × 0.85mm.

Pin/Terminal	Circuit Role	Design Meaning
1 SW	Switch node	Drain connection of internal N-MOS and P-MOS; ties to inductor; high dv/dt node requiring tight layout
2 GND	Power ground	Primary return path for switch current and feedback reference; must connect to low-impedance ground plane
3 FB	Feedback input	Senses resistor divider output; controls regulation point; sensitive analog node requiring noise isolation
4 EN	Enable control	Logic-level input (high >0.7V, low <0.15V); asserts shutdown and activates output disconnect
5 OUT	Regulated output	Source of internal P-MOS; connects directly to output capacitor; enables true V_OUT discharge on disable
6 IN	Input supply	Battery or source input (0.8–5V); powers startup circuit and bias before V_OUT stabilizes

Key Features

Feature	Design Value
True output disconnect	Eliminates body diode conduction path, allowing V_OUT to fully discharge and reducing shutdown current to <1µA
Inrush current limiting	Integrated soft-start (0.7–2.6ms) and current foldback prevent input surge during cold start from weak batteries
Low-voltage startup	Dedicated oscillator initiates operation at 0.8V input, extending usable battery life in single-cell applications
Short-circuit robustness	Combines current limit reduction, thermal regulation, and output disconnect to survive sustained output shorts without damage
V_IN > V_OUT regulation	Maintains regulated output even when input exceeds setpoint-enables seamless transition across battery discharge curves

Applications

Wireless Peripherals

Portable Audio Devices

Use Scenario: Battery-powered optical mouse with Bluetooth LE connectivity requiring stable 3.3V rail from single AA cell.

IC Role / Device Role / Timing Role: Synchronous boost converter providing regulated 3.3V output with true disconnect during sleep mode.

Use Value: Enables 0.8V startup and <1µA shutdown current, extending battery life beyond 6 months in typical usage.

Use Scenario: Flash-based MP3 player using single alkaline cell with dynamic load ranging from 10mA (idle) to 500mA (playback).

IC Role / Device Role / Timing Role: Primary DC-DC regulator delivering 5V to USB interface and 3.3V to audio codec via resistor divider.

Use Value: 96% peak efficiency at 200mA and 1.1MHz switching minimize solution size while maintaining thermal safety.

Medical Sensors

IoT Edge Nodes

Use Scenario: Disposable glucose monitor powered by coin cell, requiring precise 3.0V supply for ADC and BLE radio.

IC Role / Device Role / Timing Role: Low-noise, high-PSRR boost regulator with internal compensation eliminating external loop components.

Use Value: 1.2V feedback reference and ±40mV tolerance ensure <±1% output accuracy critical for sensor signal chain integrity.

Use Scenario: Sub-GHz wireless sensor node harvesting energy from ambient light, storing in supercapacitor, then boosting to 3.3V for MCU wake-up.

IC Role / Device Role / Timing Role: Ultra-low-input-voltage boost converter enabling operation down to 0.8V with programmable output.

Use Value: Inrush limiting and soft-start prevent supercapacitor voltage collapse during initial charge transfer to load.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
TPS61200DRCT	0.3V startup, 1.2A switch, but no true output disconnect; requires external diode	Lacks V_OUT discharge capability - unsuitable where zero standby leakage is required	Prefer MP3120DJ-LF-P when battery drain in shutdown must be <1µA
RT9013-33GJ6	Fixed 3.3V output, 0.5A switch current, no adjustable feedback or disconnect	Not programmable; limited to single-output fixed-voltage use cases	Choose MP3120DJ-LF-P for adjustable 2.5–5V outputs and battery-sensitive designs

Compared with TPS61200DRCT and RT9013-33GJ6, MP3120DJ-LF-P uniquely combines ultra-low 0.8V startup, true output disconnect, and 1.2A capability in a 6-pin TSOT23 - making it optimal for space- and battery-life-constrained portable electronics where regulation flexibility and shutdown integrity are critical.

Availability

MP3120DJ-LF-P is available at Aetrix Electronics and suitable for wireless peripherals, portable audio devices, medical sensors, and IoT edge nodes requiring stable component supply with RoHS-compliant packaging and guaranteed long-term availability.

Supply support for MP3120DJ-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.

The MP3120 belongs to MPS's synchronous boost converter product line, engineered specifically for ultra-low-voltage battery-powered applications where startup reliability, efficiency, and minimal quiescent current are essential.

FAQ

What is the minimum input voltage required for MP3120DJ-LF-P to start up?

The MP3120DJ-LF-P starts up from 0.8V input under no-load conditions, enabled by a dedicated low-voltage oscillator. This allows operation from nearly depleted single-cell alkaline or NiMH batteries. Once started, regulation continues even if input drops further, provided the battery can sustain output power demand.

Does MP3120DJ-LF-P support output voltages higher than the input voltage?

Yes - MP3120DJ-LF-P is a step-up converter designed to generate regulated outputs from 2.5V to 5V regardless of input level. It maintains regulation even when VIN exceeds VOUT, though efficiency drops significantly in that mode due to increased conduction loss in the P-MOSFET.

How does the output disconnect feature work, and what benefit does it provide?

The internal P-MOSFET disconnects the output from the input when EN is low, eliminating body-diode leakage. This allows VOUT to fully discharge and reduces shutdown current to under 1µA. It prevents back-powering of upstream circuits and extends battery shelf life in always-off systems.

Can MP3120DJ-LF-P drive a 500mA load at 5V output from a 1.5V alkaline cell?

Yes - with proper layout and component selection (e.g., 4.7µH inductor, 10µF X7R input/output caps), MP3120DJ-LF-P delivers up to 500mA at 5V from 1.5V input at ~88% efficiency. Peak switch current remains within the 1.2A limit, and thermal performance stays within safe margins at TA ≤ 60°C.

Is an external compensation network required for stable operation?

No - MP3120DJ-LF-P features fully internal compensation. The current-mode control architecture with built-in slope compensation eliminates the need for external RC networks, reducing BOM count and simplifying design validation across input/output combinations.

What package variant does MP3120DJ-LF-P use, and is it lead-free?

MP3120DJ-LF-P uses the TSOT23-6 package (2.9mm × 1.6mm × 0.85mm) with RoHS-compliant, lead-free finish. The "LF" suffix explicitly denotes lead-free plating, and the device meets JEDEC J-STD-020 moisture sensitivity level 1 requirements.

Does MP3120DJ-LF-P include short-circuit protection, and how does it behave during fault?

Yes - during output short, MP3120DJ-LF-P reduces current limit, engages thermal regulation above 125°C, and shuts down completely at 160°C. Output disconnect isolates the fault, preventing input source damage. Recovery is automatic after fault removal and cooldown.

MP3120DJ-LF-P Specifications

Product attributes: Attribute value

Manufacturer:: Monolithic Power Systems Inc.

Series:: -

Package/Case:: SOT-23-6 Thin, TSOT-23-6

Packaging:: Tape & Reel (TR)

Product Status:: Active

Function:: Step-Up

Output Configuration:: Positive

Topology:: Boost

Output Type:: Adjustable

Number of Outputs:: 1

Voltage - Input (Min):: 0.8V

Voltage - Input (Max):: 5V

Voltage - Output (Min/Fixed):: 2.5V

Voltage - Output (Max):: 5V

Current - Output:: 1.2A

Frequency - Switching:: 1.05MHz

Synchronous Rectifier:: Yes

Operating Temperature:: -40°C ~ 85°C (TA)

Grade:: -

Qualification:: -

Mounting Type:: Surface Mount

Supplier Device Package:: TSOT-23-6

MP3120DJ-LF-P FAQ

1.How can I place an order for MP3120DJ-LF-P through Aetrix?

Please submit a Request for Quotation (RFQ) for MP3120DJ-LF-P on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.

2.Are the price and stock information for MP3120DJ-LF-P reliable?

The price and inventory of MP3120DJ-LF-P are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MP3120DJ-LF-P is usually 5 days.

3.What payment methods are accepted for MP3120DJ-LF-P?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MP3120DJ-LF-P transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for MP3120DJ-LF-P?

MP3120DJ-LF-P orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your MP3120DJ-LF-P order is processed, you will receive an email with the shipment details and tracking number.

Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.

5.How can I obtain technical support or documentation for MP3120DJ-LF-P?

For technical support, including MP3120DJ-LF-P datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MP3120DJ-LF-P requirements.

6.How does Aetrix verify that MP3120DJ-LF-P is sourced from the original manufacturer or authorized distributors?

All MP3120DJ-LF-P products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that MP3120DJ-LF-P meets industry standards.

7.What is the process for return or replacement of MP3120DJ-LF-P?

All MP3120DJ-LF-P units undergo pre-shipment inspection (PSI). If there is an issue with MP3120DJ-LF-P, returns or replacements are accepted under the following conditions:

1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.

2.The issue is reported within 90 days of delivery.

3.The MP3120DJ-LF-P part is unused and in its original packaging.

Return procedure for MP3120DJ-LF-P:

1.Submit a request within 90 days.

2.Obtain a Return Material Authorization (RMA) from Aetrix.

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