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

Monolithic Power Systems Inc. MP2181GTL-Z

Name: MP2181GTL-Z
Brand: Monolithic Power Systems Inc.
SKU: MP2181GTL-Z
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: MP2181GTL-Z

Manufacturer:: Monolithic Power Systems Inc.

Category:: Voltage Regulators - DC DC Switching Regulators

Package:: SOT-583

Datasheet:: MP2181GTL-Z.pdf

Description:: IC REG BUCK ADJ 1A SOT583

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Product details

Overview

MP2181GTL-Z from Monolithic Power Systems is a monolithic synchronous step-down DC/DC converter with integrated 90mΩ high-side P-MOSFET and 50mΩ low-side N-MOSFET, delivering 1A continuous output current across 2.5V–5.5V input range while regulating output down to 0.6V. It employs constant-on-time (COT) control for fast transient response, includes power good (PG), external soft-start (SS), output discharge, and hiccup-mode short-circuit protection-ideal for portable instrumentation and battery-powered I/O rails.

For engineers reviewing the MP2181GTL-Z datasheet, MP2181GTL-Z pinout, MP2181GTL-Z application, or MP2181GTL-Z equivalent, key selection criteria include its 1.2MHz switching frequency, 21μA quiescent current, ±1% FB voltage accuracy, 100% duty-cycle capability, and SOT583 package footprint compatibility with space-constrained mobile and wireless designs.

Technical Context

The MP2181GTL-Z uses input-voltage feed-forward COT control to maintain stable 1.2MHz switching across input and output variations, eliminating loop compensation components. Its AAM (Advanced Asynchronous Modulation) + ZCD (Zero-Current Detection) architecture ensures DCM operation at light loads while sustaining regulation down to 0.6V output.

Fault handling includes cycle-by-cycle current limiting (2.5A high-side peak), thermal shutdown at 160°C with 30°C hysteresis, VO OVP (115% VFB threshold), and VIN OVP (6.1V). The open-drain PG pin asserts after 80μs delay when FB reaches 90% of target, with 0.4V sink capability at 1mA.

Key Specifications

Parameter	Value and Actual Design Meaning
Input Voltage Range	2.5V to 5.5V - supports single-cell Li-ion, USB, and 3.3V/5V rail inputs without pre-regulation.
Output Current	1A continuous - sufficient for powering DSP cores, RF transceivers, or multi-rail I/O subsystems.
Switching Frequency	1.2MHz - enables use of compact 1μH shielded inductors and reduces EMI filtering burden.
Quiescent Current	21μA - extends battery life in always-on sensor nodes and standby modes.
Feedback Accuracy	±1% at 25°C - ensures tight output regulation critical for low-voltage logic (e.g., 1.2V core, 1.8V I/O).
MOSFET R_DS(ON)	90mΩ (HS) / 50mΩ (LS) - minimizes conduction loss and thermal rise at full load.
Soft-Start Control	External SS pin with 3μA charge current - allows precise ramp rate tuning via capacitor to prevent inrush.

Pinout & Package

SOT583 package: ultra-small 1.6mm × 2.1mm, 0.5mm pitch, 8-pin leadless package with wettable flanks for automated optical inspection (AOI) and reliable reflow soldering.

Pin/Terminal	Circuit Role	Design Meaning
1 - PG	Open-drain power-good indicator	Asserts high (via external pull-up) when FB ≥ 90% of target; sinks ≤0.4V @ 1mA during fault.
2 - VIN	Main input supply	Accepts 2.5V–5.5V; requires local 10μF ceramic decoupling to suppress switching noise.
3 - SW	Switching node	Drain of internal P-MOSFET; connects directly to inductor; must be routed short and away from sensitive analog traces.
4 - GND	Power and signal ground	Common return for VIN, SW, FB, SS, EN, OUT, PG; requires solid thermal pad connection per layout guidelines.
5 - EN	Enable control	Active-high (≥1.2V); internal 2MΩ pulldown allows floating-disable; controls power sequencing.
6 - SS	Soft-start timing	Charged at 3μA; sets output ramp time; disables output discharge when pulled low during startup.
7 - OUT	Regulated output rail	Delivers up to 1A; connects to load and output capacitor; integrates discharge MOSFET when disabled.
8 - FB	Voltage feedback sense	Monitors resistor divider; 600mV reference enables adjustable outputs from 0.6V using standard 1% resistors.

Key Features

Feature	Design Value
Constant-On-Time (COT) Control	Enables instantaneous load transient response without external compensation components.
Output Discharge Function	Internal MOSFET actively discharges VOUT when EN = low, preventing residual voltage holdup in power sequencing.
100% Duty Cycle Capability	Allows dropout operation down to VOUT ≈ VIN − I_LOAD×R_{DS(ON)_HS}, critical for low-VIN applications like 2.5V input → 1.8V output.
Power Good (PG) with Hysteresis	87–93% rising / 82–88% falling FB threshold ensures clean system reset signaling under line/load variation.
Hiccup-Mode Short-Circuit Protection	Disables switching, discharges SS capacitor, then retries - prevents thermal runaway during sustained overload.

Applications

Wireless Networking Cards

Portable Instrumentation

Use Scenario: Powering 2.4GHz/5GHz Wi-Fi/BT SoCs and RF front-end modules on mini-PCIe or M.2 cards.

IC Role / Device Role / Timing Role: Primary buck regulator supplying 1.2V core and 1.8V I/O rails with fast load-step response to burst transmit cycles.

Use Value: 1.2MHz switching avoids interference with 2.4GHz ISM band; 21μA IQ extends battery runtime in handheld analyzers.

Use Scenario: Providing stable, low-noise supply to precision ADCs, op-amps, and microcontroller peripherals in handheld DMMs or oscilloscopes.

IC Role / Device Role / Timing Role: Point-of-load converter generating 3.3V or 2.5V analog rails with <1% FB accuracy and minimal output ripple.

Use Value: Integrated MOSFETs eliminate external FET layout sensitivity; SOT583 footprint saves board area in compact enclosures.

Battery-Powered IoT Sensors

Low-Voltage I/O System Power

Use Scenario: Regulating single-cell Li-ion (3.0–4.2V) to 1.8V or 3.3V for BLE/Wi-Fi MCU and sensor interface circuits.

IC Role / Device Role / Timing Role: Always-on power stage supporting deep-sleep modes with 21μA quiescent current and automatic light-load AAM mode.

Use Value: Output discharge prevents back-powering during sleep; PG signal synchronizes MCU wake-up with rail stabilization.

Use Scenario: Generating 1.2V, 1.5V, or 1.8V supplies for FPGA I/O banks, DDR termination, or ASIC auxiliary rails.

IC Role / Device Role / Timing Role: Compact, high-efficiency buck converter placed near load to minimize IR drop and noise coupling.

Use Value: 90mΩ/50mΩ R_DS(ON) delivers >90% efficiency at 1A; 100% duty cycle supports 2.5V→1.8V conversion without dropout.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
TPS62865RQYR	Higher 2A rating, 2.5V–5.5V input, but larger 1.2mm × 1.6mm DSBGA package and no PG pin.	Lacks power-good signaling; requires external circuitry for rail monitoring in safety-critical systems.	Select when higher current headroom is needed and PG is not required; verify PCB real estate for DSBGA vs SOT583.
RT7295BGJ8F	Same 1A rating and SOT583 package, but fixed 1.2MHz frequency, no SS pin, and 30μA IQ.	Missing external soft-start control limits flexibility in systems requiring controlled ramp rates or inrush limiting.	Choose for cost-sensitive designs where soft-start timing is not critical and 9μA higher IQ is acceptable.

Compared with TPS62865RQYR and RT7295BGJ8F, the MP2181GTL-Z uniquely combines PG, SS, output discharge, and 21μA IQ in the ultra-compact SOT583 footprint-making it optimal for space- and power-constrained portable electronics requiring full feature integration.

Availability

MP2181GTL-Z is available at Aetrix Electronics and suitable for wireless networking cards, portable instrumentation, battery-powered IoT sensors, and low-voltage I/O system power requiring stable component supply across production lifecycles.

Supply support for MP2181GTL-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 power management ICs, with design centers in the US, China, and Taiwan.

The MP2181 belongs to MPS's ultra-compact, high-efficiency DC/DC converter product line, engineered specifically for portable, battery-operated, and space-constrained applications demanding low IQ, fast transient response, and integrated protection features.

FAQ

What is the minimum output voltage supported by the MP2181GTL-Z?

The MP2181GTL-Z supports output voltages as low as 0.6V, set by the internal 600mV feedback reference and an external resistor divider. This enables direct regulation for modern low-voltage logic such as 0.8V GPU cores or 0.9V FPGA rails when paired with precision 1% resistors.

Does the MP2181GTL-Z require external compensation components?

No. The MP2181GTL-Z uses constant-on-time (COT) control with input-voltage feed-forward, eliminating the need for external loop compensation components like type-II or type-III networks. This simplifies design, reduces BOM count, and improves stability across input/output variations.

How does the output discharge function operate?

When the EN pin is pulled low, the MP2181GTL-Z activates an internal discharge MOSFET between OUT and GND, providing a 150Ω path to rapidly deplete the output capacitor. This prevents residual voltage from interfering with power sequencing or causing latch-up in downstream logic.

Can the MP2181GTL-Z operate with 100% duty cycle?

Yes. The MP2181GTL-Z supports 100% duty cycle operation, allowing it to maintain regulation even when VIN approaches VOUT (e.g., 2.5V input → 1.8V output), which is essential for maximizing battery utilization in single-cell systems.

What is the purpose of the SS pin, and how is soft-start time calculated?

The SS pin accepts an external capacitor to control output voltage ramp rate. With a typical 3μA internal charge current, soft-start time t_SS ≈ (C_SS × 0.6V) / 3μA. For example, a 2.2nF capacitor yields ~440μs ramp time, preventing inrush current and overshoot during startup.

Is the PG pin open-drain, and what pull-up value is recommended?

Yes, PG is an open-drain output requiring an external pull-up resistor. A value between 100kΩ and 500kΩ to VOUT or VIN is recommended. Lower values improve noise immunity but increase static current; higher values reduce current but may slow edge transitions in noisy environments.

What thermal performance can be expected in the SOT583 package?

In a 2-layer JEDEC EV2181-TL-00A evaluation board, the SOT583 package exhibits θ_JA = 58°C/W. At 1A load and 3.6V input, typical power dissipation is ~180mW, resulting in ~10.5°C junction-to-ambient rise above ambient-well within the 125°C max operating junction temperature.

MP2181GTL-Z Specifications

Product attributes: Attribute value

Manufacturer:: Monolithic Power Systems Inc.

Series:: -

Package/Case:: SOT-583

Packaging:: Tape & Reel (TR)

Product Status:: Active

Function:: -

Output Configuration:: Positive

Topology:: Buck

Output Type:: Adjustable

Number of Outputs:: 1

Voltage - Input (Min):: 2.5V

Voltage - Input (Max):: 5.5V

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

Voltage - Output (Max):: 5.5V

Current - Output:: 1A

Frequency - Switching:: 1.2MHz

Synchronous Rectifier:: Yes

Operating Temperature:: -40°C ~ 125°C (TJ)

Grade:: -

Qualification:: -

Mounting Type:: Surface Mount

Supplier Device Package:: SOT-583

MP2181GTL-Z FAQ

1.How can I place an order for MP2181GTL-Z through Aetrix?

Please submit a Request for Quotation (RFQ) for MP2181GTL-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 MP2181GTL-Z reliable?

The price and inventory of MP2181GTL-Z are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MP2181GTL-Z is usually 5 days.

3.What payment methods are accepted for MP2181GTL-Z?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MP2181GTL-Z transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for MP2181GTL-Z?

MP2181GTL-Z orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your MP2181GTL-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 MP2181GTL-Z?

For technical support, including MP2181GTL-Z datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MP2181GTL-Z requirements.

6.How does Aetrix verify that MP2181GTL-Z is sourced from the original manufacturer or authorized distributors?

All MP2181GTL-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 MP2181GTL-Z meets industry standards.

7.What is the process for return or replacement of MP2181GTL-Z?

All MP2181GTL-Z units undergo pre-shipment inspection (PSI). If there is an issue with MP2181GTL-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 MP2181GTL-Z part is unused and in its original packaging.

Return procedure for MP2181GTL-Z:

1.Submit a request within 90 days.

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

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