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

Monolithic Power Systems Inc. MP2159GJ-P

Name: MP2159GJ-P
Brand: Monolithic Power Systems Inc.
SKU: MP2159GJ-P
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: MP2159GJ-P

Manufacturer:: Monolithic Power Systems Inc.

Category:: Voltage Regulators - DC DC Switching Regulators

Package:: SOT-23-8 Thin, TSOT-23-8

Datasheet:: MP2159GJ-P.pdf

Description:: IC REG BUCK ADJ 1A TSOT23-8

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Product details

Overview

MP2159GJ-P from Monolithic Power Systems is a synchronous step-down DC/DC converter IC with integrated 118mΩ high-side and 88mΩ low-side MOSFETs, delivering 1A continuous output current from 2.5V–6V input while regulating output down to 0.6V. It employs Constant-On-Time (COT) control for fast transient response, features 17μA quiescent current, 1.5MHz switching frequency, and integrated power-good (PG) and enable (EN) functions - ideal for powering FPGAs, DSPs, and portable instrumentation.

For engineers reviewing the MP2159GJ-P datasheet, MP2159GJ-P pinout, MP2159GJ-P application, or MP2159GJ-P equivalent, key selection criteria include its TSOT23-8 package footprint, COT-based light-load efficiency optimization, ±10% PG threshold accuracy, 60ns minimum off-time constraint, and compatibility with low-ESR ceramic output capacitors without external compensation.

Technical Context

The MP2159GJ-P implements a proprietary Constant-On-Time control architecture with input-voltage feedforward, enabling near-constant 1.5MHz switching across 2.5V–6V input and 0.6V–VIN output ranges. Its on-time is approximated as T_ON ≈ 0.667 μs × V_OUT/V_IN, while a fixed 60ns minimum off-time prevents inductor current runaway during transients.

It integrates cycle-by-cycle overcurrent protection with ~2A PFET current limit, hiccup-mode short-circuit recovery, thermal shutdown at 150°C (30°C hysteresis), and a dedicated analog ground (AGND) pin to isolate noise-sensitive feedback circuitry from power ground (PGND).

Key Specifications

Parameter	Value and Actual Design Meaning
Input Voltage Range	2.5V to 6V - supports single-cell Li-ion, USB-powered, and multi-rail intermediate bus systems.
Output Voltage Range	0.6V to VIN - enables core voltage regulation for modern low-V_DD processors and I/O rails.
Max Output Current	1A continuous - sufficient for FPGA I/O banks, ARM Cortex-A/M cores, and sensor hubs.
Quiescent Current	17μA - extends battery life in always-on subsystems like RTC or BLE wake-up circuits.
Switching Frequency	1.5MHz ±20% - allows compact 1μH inductors and reduces EMI filtering burden.
Feedback Accuracy	±3% at 25°C, ±3.5% over –40°C to +85°C - ensures stable regulation under thermal stress.
Power Good Threshold	±10% of 0.6V (i.e., 0.54V–0.66V) - provides reliable sequencing signal for downstream logic.

Pinout & Package

MP2159GJ-P is housed in an 8-pin TSOT23-8 package (2.9mm × 1.6mm × 0.85mm), optimized for space-constrained portable designs. The thermally enhanced layout places PGND and AGND on adjacent pins to minimize ground bounce, and SW is isolated from FB to suppress noise coupling.

Pin/Terminal	Circuit Role	Design Meaning
1 - PG	Open-drain power-good indicator	Pulled up to VIN via internal 500kΩ resistor; asserts high only when FB is within ±10% of 0.6V - used for system power sequencing and fault detection.
2 - VIN	Main input supply	Accepts 2.5V–6V unregulated input; requires local 10μF ceramic decoupling to suppress high-frequency switching noise.
3 - SW	Switch node	Connects to external inductor; carries high di/dt pulsed current - must be routed short and away from sensitive analog traces (FB, AGND).
4 - PGND	Power ground return	Low-impedance return path for high-current switch loop (VIN → PFET → SW → inductor → PGND); separate from AGND to avoid noise injection.
5 - OUT	Output voltage sense	Direct connection to output capacitor anode; improves load regulation by compensating for PCB trace resistance between IC and load.
6 - AGND	Analog ground reference	Reference for internal error amplifier and feedback comparator; must be tied to PGND at single point near IC to prevent ground loops.
7 - FB	Feedback input	Monitors output via external resistor divider; sets V_OUT = 0.6V × (1 + R1/R2); high-impedance (10–50nA bias) minimizes divider current loss.
8 - EN	Enable control	Active-high logic input (1.2V threshold); internal 1MΩ pull-down allows default disable; supports controlled power-up sequencing.

Key Features

Feature	Design Value
Constant-On-Time (COT) Control	Enables zero-phase-margin compensation-free design and <10μs load transient recovery - critical for burst-mode processor workloads.
100% Duty Cycle Operation	Permits dropout mode when V_IN ≤ V_OUT + V_RDSON×I_LOAD, maintaining regulation during brownout without external LDO fallback.
Light-Load DCM Optimization	Proprietary ZCD-based low-side gate turn-off eliminates reverse inductor current, reducing switching losses and improving >85% efficiency at 1mA load.
Integrated Power-Good (PG)	Open-drain PG with internal 500kΩ pull-up and <100Ω sink capability enables direct interfacing with FPGA configuration logic or microcontroller reset inputs.
Robust Fault Protection	Cycle-by-cycle current limiting (2A typ), thermal shutdown (150°C), and hiccup-mode short-circuit recovery prevent latch-up and field failures.

Applications

Portable Medical Sensors

FPGA Core Voltage Supply

Use Scenario: Wearable ECG patch requiring ultra-low-power 1.2V rail for analog front-end and BLE SoC.

IC Role / Device Role / Timing Role: Primary buck regulator supplying regulated 1.2V from 3.6V Li-ion battery; PG signals MCU when rail is stable.

Use Value: 17μA I_Q extends battery runtime beyond 7 days in sleep mode; COT control maintains <1% output deviation during BLE transmit bursts.

Use Scenario: Low-cost industrial FPGA board needing clean 1.0V core supply with tight sequencing relative to I/O bank rails.

IC Role / Device Role / Timing Role: Dedicated core voltage regulator with EN/PG pins synchronized to system power manager for safe configuration startup.

Use Value: ±3% FB accuracy and 1.5MHz switching ensure minimal voltage droop during FPGA configuration; TSOT23-8 footprint saves PCB area vs. larger QFN alternatives.

USB-Powered Test Instruments

Automotive Infotainment I/O Rails

Use Scenario: Handheld oscilloscope powered from 5V USB port, requiring 3.3V and 1.8V rails from single input.

IC Role / Device Role / Timing Role: Secondary buck stage generating 1.8V from intermediate 3.3V rail; operates in CCM for low-noise analog section.

Use Value: Stable operation with ceramic capacitors eliminates need for tantalum or polymer caps; 60ns min-off-time prevents subharmonic oscillation at light loads.

Use Scenario: In-vehicle display module needing 2.5V I/O supply compliant with automotive temperature range (–40°C to +125°C).

IC Role / Device Role / Timing Role: Point-of-load regulator converting 5V domain to 2.5V for LVDS transmitter interface; thermal shutdown protects against enclosure overheating.

Use Value: Guaranteed ±3.5% FB accuracy over full junction temperature range ensures reliable LVDS eye diagram integrity; 118mΩ/88mΩ MOSFETs limit self-heating at 800mA load.

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
TPS62865RVL	Higher 2A output, 2.5V–5.5V input, 2.4MHz f_SW, but 25μA I_Q; uses voltage-mode control requiring external compensation.	Better suited for higher-current FPGA cores; less optimal for battery longevity due to higher I_Q and no 100% duty cycle.	Select if peak current >1A is required and PCB area allows larger 1.2mm × 1.6mm WCSP package.
RT7290BZSP	1.2A output, 4.5V–18V input, 500kHz f_SW, 30μA I_Q; lacks PG and EN pins; requires external bootstrap capacitor.	Targeted at industrial 12V input systems; unsuitable for USB or single-cell Li-ion due to higher VIN min.	Choose only for cost-sensitive 12V intermediate bus applications where sequencing and ultra-low I_Q are non-critical.

Compared with TPS62865RVL and RT7290BZSP, MP2159GJ-P uniquely balances ultra-low quiescent current (17μA), 100% duty cycle capability, integrated PG/EN, and TSOT23-8 footprint - making it the optimal choice for space- and battery-limited portable electronics requiring precise, sequenced low-voltage rails.

Availability

MP2159GJ-P is available at Aetrix Electronics and suitable for portable medical sensors, FPGA core supplies, USB-powered test instruments, and automotive infotainment I/O rails requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for MP2159GJ-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 across Asia and North America and global manufacturing partnerships.

The MP2159 belongs to MPS's COT-controlled monolithic buck converter product line, engineered specifically for battery-powered and space-constrained applications demanding high efficiency at light loads, fast transient response, and minimal external component count.

FAQ

What is the maximum allowable input voltage for MP2159GJ-P, and what happens above that limit?

The absolute maximum input voltage is 6.5V. Exceeding this rating risks permanent damage to the internal PFET and control circuitry. The device incorporates under-voltage lockout (UVLO) with a rising threshold of 2.3V (±150mV), but no overvoltage protection circuitry - external TVS or clamp diodes are recommended if input transients exceed 6.5V.

Can MP2159GJ-P operate with 100% duty cycle, and under what conditions?

Yes - MP2159GJ-P supports 100% duty cycle operation when input voltage drops near the output voltage plus I_LOAD × R_{DS(ON)_P}. This allows continued regulation during brownout events without requiring a parallel LDO, provided the thermal limit (150°C junction) is not exceeded at high ambient temperatures and full load.

How does the Power Good (PG) pin behave during startup and fault conditions?

PG is an open-drain output pulled up to VIN via an internal 500kΩ resistor. It asserts high only when FB voltage remains within ±10% of 0.6V for ≥50μs after soft-start completes. During startup, PG stays low until output settles; during overcurrent or thermal shutdown, PG pulls low within microseconds to signal fault to host controller.

What is the recommended output capacitor type and minimum value for stable operation?

MPS recommends X5R/X7R ceramic capacitors with ≤10mΩ ESR. A minimum of 10μF is required for most 1.2V–3.3V outputs; for 5V outputs or high-transient loads, 22μF is advised. The capacitor must be placed directly between OUT and PGND pins, with short, wide traces to minimize ESL and ensure <10mV peak-to-peak ripple at 1A load.

Does MP2159GJ-P require external compensation components, and why?

No - MP2159GJ-P uses Constant-On-Time (COT) control with built-in input-voltage feedforward, eliminating the need for external compensation networks. This simplifies design, reduces BOM count, and guarantees stability with standard ceramic output capacitors (10–47μF), unlike voltage-mode buck controllers that require careful loop compensation.

What is the thermal resistance (θ_JA) of the TSOT23-8 package, and how does it affect power dissipation?

The specified θ_JA is 100°C/W on a 4-layer JEDEC JESD51-7 PCB. At 25°C ambient and 1A load with 5V input → 1.2V output, power dissipation is ~0.3W, resulting in ~30°C junction rise - well below the 125°C max operating temperature. For continuous 1A operation at 6V→1.2V, derating or improved copper pour is advised to maintain TJ < 125°C.

How does the soft-start function work, and can its duration be adjusted?

MP2159GJ-P has a fixed 1.5ms typical soft-start time implemented via internal current source charging an external capacitor on the SS pin (not present on MP2159GJ-P - soft-start is fully internal). The output voltage ramps linearly from 0V to final setpoint, preventing inrush current and overshoot. Duration cannot be adjusted externally; no SS pin is provided in TSOT23-8 variant.

MP2159GJ-P Specifications

Product attributes: Attribute value

Manufacturer:: Monolithic Power Systems Inc.

Series:: -

Package/Case:: SOT-23-8 Thin, TSOT-23-8

Packaging:: Tape & Reel (TR)

Product Status:: Active

Function:: Step-Down

Output Configuration:: Positive

Topology:: Buck

Output Type:: Adjustable

Number of Outputs:: 1

Voltage - Input (Min):: 2.5V

Voltage - Input (Max):: 6V

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

Voltage - Output (Max):: 6V

Current - Output:: 1A

Frequency - Switching:: 1.5MHz

Synchronous Rectifier:: Yes

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

Grade:: -

Qualification:: -

Mounting Type:: Surface Mount

Supplier Device Package:: TSOT-23-8

MP2159GJ-P FAQ

1.How can I place an order for MP2159GJ-P through Aetrix?

Please submit a Request for Quotation (RFQ) for MP2159GJ-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 MP2159GJ-P reliable?

The price and inventory of MP2159GJ-P are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MP2159GJ-P is usually 5 days.

3.What payment methods are accepted for MP2159GJ-P?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MP2159GJ-P transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for MP2159GJ-P?

MP2159GJ-P orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your MP2159GJ-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 MP2159GJ-P?

For technical support, including MP2159GJ-P datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MP2159GJ-P requirements.

6.How does Aetrix verify that MP2159GJ-P is sourced from the original manufacturer or authorized distributors?

All MP2159GJ-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 MP2159GJ-P meets industry standards.

7.What is the process for return or replacement of MP2159GJ-P?

All MP2159GJ-P units undergo pre-shipment inspection (PSI). If there is an issue with MP2159GJ-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 MP2159GJ-P part is unused and in its original packaging.

Return procedure for MP2159GJ-P:

1.Submit a request within 90 days.

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

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