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

Monolithic Power Systems Inc. MP2109DQ-LF-Z

Name: MP2109DQ-LF-Z
Brand: Monolithic Power Systems Inc.
SKU: MP2109DQ-LF-Z
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: MP2109DQ-LF-Z

Manufacturer:: Monolithic Power Systems Inc.

Category:: Voltage Regulators - DC DC Switching Regulators

Package:: 10-VFDFN Exposed Pad

Datasheet:: MP2109DQ-LF-Z.pdf

Description:: IC REG BUCK ADJ 800MA DL 10QFN

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Product details

Overview

MP2109DQ-LF-Z from Monolithic Power Systems is a dual-channel synchronous step-down DC-DC converter with two independent 1.2MHz current-mode PWM regulators, each delivering up to 800mA from 2.5V–6V input and regulating output down to 0.6V; integrates main PFET and synchronous NFET switches per channel, supports 100% duty cycle for low-dropout operation, and targets single-cell Li+-powered portable electronics.

For engineers reviewing the MP2109DQ-LF-Z datasheet, MP2109DQ-LF-Z pinout, MP2109DQ-LF-Z application, or MP2109DQ-LF-Z equivalent, key selection criteria include dual-channel independent feedback (FB1/FB2 = 0.6V), QFN10 (3mm × 3mm) thermal performance (θJA = 50°C/W), shutdown current <0.1µA, and verified short-circuit/thermal protection behavior.

Technical Context

The MP2109DQ-LF-Z implements two fully independent current-mode PWM controllers with slope compensation, enabling stable regulation at duty cycles >50% and fast transient response. Each channel features dedicated EN, FB, SW, IN, and GND terminals, with internal 0.6V reference and ±2% FB voltage accuracy over –40°C to +85°C.

It operates with fixed 1.2MHz switching frequency (±20%), integrates both high-side PFET (R_DS(on) = 0.42Ω) and low-side NFET (R_DS(on) = 0.26Ω), and enters 100% duty-cycle dropout mode when V_IN approaches V_OUT, maintaining regulation without external diode.

Key Specifications

Parameter	Value and Actual Design Meaning
Switching Frequency	1.2MHz ±20%; enables compact 2.2–4.7µH inductor selection and reduces EMI filter size.
Max Output Current (per channel)	800mA continuous; supported by integrated PFET/NFET with R_DS(on) ≤0.42Ω/0.26Ω.
Input Voltage Range	2.5V to 6V; compatible with single-cell Li-ion (2.7–4.2V) and 3.3V/5V rails.
Feedback Reference Voltage	0.600V ±2%; sets output via external resistor divider, enabling precise 0.6–6V regulation.
Shutdown Current	<0.1µA typical; minimizes battery drain in standby mode of portable devices.
Thermal Shutdown Threshold	150°C; protects device under overload or poor PCB thermal design.
UVLO Threshold	2.30V rising edge with 55mV hysteresis; prevents erratic startup near battery depletion.

Pinout & Package

MP2109DQ-LF-Z uses a thermally enhanced 10-pin QFN package (3mm × 3mm, 0.5mm pitch) with exposed thermal pad on underside for PCB heat sinking. Pin numbering follows JEDEC MO-229 VEED-5 standard.

Pin/Terminal	Circuit Role	Design Meaning
EN1	Channel 1 enable control	Logic-level input: >1.5V enables, <0.3V disables with <0.1µA shutdown current.
FB1	Channel 1 feedback sense	Connects to resistor divider midpoint; regulates V_OUT1 to 0.6V reference.
IN2	Channel 2 input supply	Accepts 2.5–6V; requires local 2.2µF+ ceramic bypass to GND2.
GND2	Channel 2 power ground	Separate ground return path for Channel 2 to minimize cross-talk.
SW2	Channel 2 switch node	Drain connection of internal PFET/NFET; connects to inductor and output capacitor.
EN2	Channel 2 enable control	Independent logic-level enable matching EN1 functionality.
FB2	Channel 2 feedback sense	Regulates V_OUT2 independently using same 0.6V reference.
IN1	Channel 1 input supply	Accepts 2.5–6V; requires local 2.2µF+ ceramic bypass to GND1.
GND1	Channel 1 power ground	Separate ground return path for Channel 1; improves PSRR between channels.
SW1	Channel 1 switch node	Drain connection of internal PFET/NFET; connects to inductor and output capacitor.

Key Features

Feature	Design Value
Dual independent regulation	Two fully isolated 1.2MHz PWM channels with separate EN, FB, IN, GND, and SW pins-enables asymmetric rail generation (e.g., 1.8V + 1.2V) without coupling.
Synchronous rectification	Integrated NFET replaces Schottky diode, eliminating forward drop loss and improving efficiency up to 95% at 800mA.
100% duty-cycle operation	Enables dropout mode when V_IN ≈ V_OUT; maintains regulation without external components as input decays near battery end-of-life.
Current-mode control with slope compensation	Provides inherent cycle-by-cycle current limiting, stable loop response at >50% duty, and immunity to sub-harmonic oscillation.
Comprehensive protection	Includes thermal shutdown (150°C), short-circuit foldback (reduced f_OSC and I_LIM), and UVLO-ensures robustness in portable systems.

Applications

Cellular and Smart Phones

Microprocessors and DSP Core Supplies

Use Scenario: Powering application processor cores and memory I/O rails in compact smartphones with single-cell Li-ion battery.

IC Role / Device Role / Timing Role: Dual-channel PMIC providing independent 1.2V (core) and 1.8V (I/O) supplies with tight load transient response.

Use Value: Eliminates need for two discrete converters; 1.2MHz switching allows small 2.2µH inductors and 10µF ceramic output caps, saving board space.

Use Scenario: Delivering clean, regulated voltages to low-power DSPs and microcontrollers in handheld test instruments.

IC Role / Device Role / Timing Role: High-efficiency dual buck regulator supplying core (1.2V) and peripheral (3.3V) rails from shared 3.6V input.

Use Value: Internal compensation and 0.6V FB reference simplify design; <0.1µA shutdown current extends battery life during idle periods.

PDAs

Digital Still and Video Cameras

Use Scenario: Generating multiple low-noise rails for display backlight, image sensor, and baseband ICs in legacy PDA platforms.

IC Role / Device Role / Timing Role: Dual-step-down converter supporting dynamic voltage scaling (DVS) via independent EN control per channel.

Use Value: 100% duty-cycle capability sustains output during battery voltage sag (e.g., 3.0V → 1.8V), avoiding system reset.

Use Scenario: Powering CMOS image sensor analog front-end and digital processing block in compact video cameras.

IC Role / Device Role / Timing Role: Dual buck regulator delivering 1.2V (sensor analog) and 2.8V (digital logic) from 3.7V Li-ion cell.

Use Value: Separate GND1/GND2 pins reduce ground bounce between analog and digital domains, lowering noise on sensitive sensor outputs.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
MP2149DQ-LF-Z	Successor device with improved efficiency (up to 96%), lower quiescent current (350µA vs. 600µA), and extended input range (2.3V–6.5V).	Same pinout and footprint; supports newer designs requiring longer battery runtime and wider VIN tolerance.	Select MP2149DQ-LF-Z for new designs-MP2109DQ-LF-Z is marked "Not Recommended for New Designs" in official documentation.
TPS62400DRVR	TI dual 3MHz buck with 600mA per channel, 2.5V–6V input, but lacks 100% duty-cycle mode and has higher shutdown current (1µA).	Higher switching frequency enables smaller passives but reduced dropout capability limits use in deep-discharge Li-ion scenarios.	Choose only if 3MHz operation and TI ecosystem support outweigh need for 100% duty cycle and ultra-low shutdown current.

Compared with MP2149DQ-LF-Z, the MP2109DQ-LF-Z offers identical pin compatibility but lower efficiency and higher quiescent current; versus TPS62400DRVR, it provides superior dropout behavior and lower shutdown leakage, making it more suitable for battery-critical portable applications despite older architecture.

Availability

MP2109DQ-LF-Z is available at Aetrix Electronics and suitable for cellular phones, portable instrumentation, and digital cameras requiring stable component supply across extended production lifecycles.

Supply support for MP2109DQ-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, headquartered in Kirkland, WA, with global design and support operations.

The MP2109 belongs to MPS's high-frequency synchronous buck converter product line, designed specifically for space-constrained, battery-powered portable electronics demanding high efficiency, minimal external components, and robust protection.

FAQ

What is the maximum recommended output current per channel for MP2109DQ-LF-Z?

The MP2109DQ-LF-Z delivers up to 800mA continuous load current per channel under typical conditions (T_A = 25°C, V_IN = 3.6V, V_OUT = 1.8V). At elevated ambient temperatures or lower input voltages (e.g., 2.5V), derating applies due to thermal limits and increased conduction losses-maximum junction temperature must remain below 150°C.

Does MP2109DQ-LF-Z require external compensation components?

No. The MP2109DQ-LF-Z features internally compensated error amplifiers, eliminating the need for external compensation networks. Designers only need to select appropriate output capacitors (e.g., 10µF X5R/X7R ceramic) and inductors (e.g., 2.2µH) per channel to ensure stability and meet ripple requirements.

Can MP2109DQ-LF-Z operate with only one channel enabled?

Yes. Channels are fully independent-EN1 and EN2 can be controlled separately. Disabling one channel (e.g., pulling EN2 low) reduces total quiescent current to ~440µA while the active channel continues normal regulation, enabling flexible power sequencing in multi-rail systems.

What is the purpose of separate GND1 and GND2 pins?

GND1 and GND2 provide dedicated ground return paths for Channel 1 and Channel 2, respectively. This separation minimizes ground-bounce coupling between channels, especially critical when powering noise-sensitive analog circuits (e.g., image sensors) alongside digital loads, improving PSRR and reducing crosstalk-induced ripple.

Is MP2109DQ-LF-Z RoHS compliant and lead-free?

Yes. The "-LF" suffix explicitly denotes lead-free construction, and the device complies with RoHS Directive 2011/65/EU. The QFN10 package uses matte tin (Sn) termination, and all materials meet JEDEC J-STD-020 moisture sensitivity level (MSL) 3 requirements.

How does short-circuit protection work on MP2109DQ-LF-Z?

Upon output short-to-ground detection, the MP2109DQ-LF-Z reduces switching frequency and lowers the PFET current limit to limit fault current. Once the short is removed and FB voltage recovers to ≥0.6V, normal operation resumes automatically-no latch-off or manual reset required.

What is the minimum output voltage achievable with MP2109DQ-LF-Z?

The MP2109DQ-LF-Z regulates output down to 0.6V, set by its internal feedback reference voltage. Using standard 1% resistors (e.g., R1 = 300kΩ, R2 = 150kΩ), it achieves precise 1.8V output; lower outputs (e.g., 0.8V) are possible but require tighter resistor tolerance to maintain accuracy within ±2% FB voltage drift.

MP2109DQ-LF-Z Specifications

Product attributes: Attribute value

Manufacturer:: Monolithic Power Systems Inc.

Series:: -

Package/Case:: 10-VFDFN Exposed Pad

Packaging:: Tape & Reel (TR)

Product Status:: Not For New Designs

Function:: Step-Down

Output Configuration:: Positive

Topology:: Buck

Output Type:: Adjustable

Number of Outputs:: 2

Voltage - Input (Min):: 2.5V

Voltage - Input (Max):: 6V

Voltage - Output (Min/Fixed):: 0.6V

Voltage - Output (Max):: 6V

Current - Output:: 800mA

Frequency - Switching:: 1.24MHz

Synchronous Rectifier:: Yes

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

Grade:: -

Qualification:: -

Mounting Type:: Surface Mount

Supplier Device Package:: 10-QFN (3x3)

MP2109DQ-LF-Z FAQ

1.How can I place an order for MP2109DQ-LF-Z through Aetrix?

Please submit a Request for Quotation (RFQ) for MP2109DQ-LF-Z 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 MP2109DQ-LF-Z reliable?

The price and inventory of MP2109DQ-LF-Z are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MP2109DQ-LF-Z is usually 5 days.

3.What payment methods are accepted for MP2109DQ-LF-Z?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MP2109DQ-LF-Z transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for MP2109DQ-LF-Z?

MP2109DQ-LF-Z orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your MP2109DQ-LF-Z 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 MP2109DQ-LF-Z?

For technical support, including MP2109DQ-LF-Z datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MP2109DQ-LF-Z requirements.

6.How does Aetrix verify that MP2109DQ-LF-Z is sourced from the original manufacturer or authorized distributors?

All MP2109DQ-LF-Z 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 MP2109DQ-LF-Z meets industry standards.

7.What is the process for return or replacement of MP2109DQ-LF-Z?

All MP2109DQ-LF-Z units undergo pre-shipment inspection (PSI). If there is an issue with MP2109DQ-LF-Z, 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 MP2109DQ-LF-Z part is unused and in its original packaging.

Return procedure for MP2109DQ-LF-Z:

1.Submit a request within 90 days.

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

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