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

Monolithic Power Systems Inc. MP4558DN-LF

Name: MP4558DN-LF
Brand: Monolithic Power Systems Inc.
SKU: MP4558DN-LF
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: MP4558DN-LF

Manufacturer:: Monolithic Power Systems Inc.

Category:: Voltage Regulators - DC DC Switching Regulators

Package:: 8-SOIC (0.154", 3.90mm Width) Exposed Pad

Datasheet:: MP4558DN-LF.pdf

Description:: IC REG BUCK ADJ 1A 8SOIC

Quantity:: RFQ Add To RFQ list

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Product details

Overview

MP4558DN-LF from Monolithic Power Systems is a non-synchronous step-down DC/DC converter with integrated 250mΩ high-side 55V MOSFET, delivering up to 1A output current at up to 2MHz switching frequency across a 3.8V–55V input range. It features current-mode control, internal soft-start, and 140μA quiescent current-designed for automotive power rails, industrial distributed supplies, and battery-powered systems requiring compact high-voltage regulation.

For engineers reviewing the MP4558DN-LF datasheet, MP4558DN-LF pinout, MP4558DN-LF application, or MP4558DN-LF equivalent, key selection criteria include its 55V max input rating, SOIC8E package thermal performance (θJA = 50°C/W), programmable 0.8–1.2MHz oscillator via FREQ pin, and compatibility with ceramic output capacitors without external compensation complexity.

Technical Context

The MP4558DN-LF implements peak-current-mode PWM control with cycle-by-cycle current limiting and frequency fold-back during startup or short-circuit events. Its error amplifier delivers 400V/V gain and 120μA/V transconductance, referenced to a precision 0.800V ±2% internal feedback voltage.

Operation includes pulse-skipping mode under light load to maintain >90% efficiency down to 1mA, thermal shutdown at 150°C with 20°C hysteresis, and bootstrap driver UVLO (2.2V rising threshold) ensuring gate drive integrity. The 100ns minimum on-time and 100ns minimum off-time constrain practical duty-cycle range at 2MHz.

Key Specifications

Parameter	Value and Actual Design Meaning
Input Voltage Range	3.8V to 55V - supports direct connection to automotive battery (cold crank), 48V industrial rails, and wide-input industrial SMPS.
Max Output Current	1A - limited by internal MOSFET R_DS(ON) (250mΩ typ) and thermal design; derates above +85°C ambient.
Switching Frequency	Programmable 0.8–1.2MHz (via FREQ pin resistor) - enables EMI-sensitive designs (e.g., AM radio band avoidance) and small external magnetics.
Feedback Reference	0.800V ±2% - sets output voltage accuracy; enables adjustable outputs from 0.8V to 52V using standard resistor dividers.
Quiescent Current	140μA - enables >10-year battery life in always-on monitoring nodes powered from coin cells or LiSOCl₂.
Shutdown Current	12μA - ensures minimal leakage in system sleep states; EN pin threshold is 1.55V (rising), 1.4V (falling).
Thermal Shutdown	150°C activation with 20°C hysteresis - protects against sustained overload or poor PCB heatsinking without latch-off behavior.

Pinout & Package

MP4558DN-LF uses the SOIC8E (exposed pad) package, providing enhanced thermal dissipation (θ_JA = 50°C/W, θ_JC = 10°C/W) versus standard SOIC8. The exposed pad must be soldered to a dedicated GND plane for reliable 1A operation.

Pin	Circuit Role	Design Meaning
1 (SW)	Switch Node	Drives external Schottky rectifier; requires low-inductance layout and local ceramic bypass to minimize ringing and EMI.
2 (EN)	Enable Input	Logic-level control: >1.55V enables regulator; <1.4V disables with 12μA shutdown current; internal 1μA pull-up allows floating-enable.
3 (COMP)	Error Amplifier Output	GM amplifier output for loop compensation; connects to RC network setting pole-zero for stability across load/capacitance variations.
4 (FB)	Feedback Input	Senses output voltage divider; referenced to 0.800V internal reference; leakage <1.0μA minimizes divider error.
5 (GND)	Power & Signal Ground	Primary return path; exposed pad must be connected to solid GND plane to manage heat and reduce noise coupling.
6 (FREQ)	Oscillator Programming	Resistor-to-GND sets switching frequency; 95kΩ yields ~1MHz; supports EMI optimization and magnetics size reduction.
7 (VIN)	Main Power Input	Supplies control circuitry and high-side driver; requires local 4.7μF ceramic decoupling adjacent to pin.
8 (BST)	Bootstrap Supply	Charges external BST capacitor (VIN–SW); enables floating gate drive for high-side MOSFET; requires low-ESR ceramic cap.

Key Features

Feature	Design Value
Integrated High-Voltage MOSFET	55V rated, 250mΩ R_DS(ON) - eliminates external switch, reduces BOM count, and simplifies layout for 48V input systems.
Current-Mode Control	Fast transient response with inherent cycle-by-cycle current limiting - enables stable operation with wide output capacitance ranges (10–220μF ceramic).
Internal Soft-Start	0.5ms ramp time - prevents output overshoot and inrush current during power-up or fault recovery.
Ceramic-Capacitor Stable	No external compensation required for typical 22μF X7R output caps - reduces footprint and cost vs. electrolytic-based solutions.
Frequency Fold-Back	Reduces switching frequency under overload/short-circuit - limits power dissipation and maintains thermal safety without latch-off.

Applications

Automotive Body Control Module

Industrial PLC I/O Power

Use Scenario: Regulating 12V battery input to 3.3V for microcontroller, CAN transceiver, and sensor interface in door module.

IC Role / Device Role / Timing Role: Primary non-isolated buck converter supplying core logic rail; operates continuously across -40°C to +125°C junction range.

Use Value: 55V input rating withstands load-dump transients (ISO 7637-2 Pulse 5a); 140μA IQ extends battery backup runtime during ignition-off state.

Use Scenario: Generating 5V/1A from 24V or 48V backplane in modular PLC chassis with multiple I/O cards.

IC Role / Device Role / Timing Role: Point-of-load regulator per slot; handles variable load steps (0–1A) with <5% output deviation due to current-mode control.

Use Value: 2MHz capability allows use of 4.7μH inductors (<7mm × 7mm), reducing board area vs. 500kHz alternatives requiring ≥10μH.

Battery-Powered Telematics Unit

Distributed Telecom Power

Use Scenario: Powering GPS/GSM module from Li-ion (3.0–4.2V) or 12V vehicle supply in fleet tracking device.

IC Role / Device Role / Timing Role: Dual-input buck converter supporting both battery and accessory power; EN pin enables seamless source handover.

Use Value: 12μA shutdown current preserves battery charge during multi-week idle periods; wide VIN accommodates undervoltage cutoff and boost-buck transitions.

Use Scenario: Local 3.3V rail generation for FPGA configuration and SerDes in remote radio head (RRH) powered from -48V telecom supply.

IC Role / Device Role / Timing Role: Intermediate buck stage stepping -48V to 12V, followed by secondary buck to 3.3V; MP4558DN-LF handles first conversion.

Use Value: 3.8V–55V input range accepts rectified -48V (≈68V peak) with margin; SOIC8E package supports conformal coating for outdoor environmental sealing.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
MP4571DN-LF	Successor part: 2A output, 55V input, 2MHz, lower 75μA IQ, integrated synchronous rectifier.	Replaces MP4558DN-LF in new designs requiring higher current or improved efficiency (>94% at 1A).	Select MP4571DN-LF when upgrading for higher load, lower thermal stress, or synchronous efficiency gains.
LM5164QDDARQ1	Automotive-grade (AEC-Q100), 1A, 65V input, 2.2MHz, external MOSFETs, higher BOM count.	Required for ASIL-B functional safety systems where diagnostic coverage or qualification is mandatory.	Choose LM5164QDDARQ1 only when AEC-Q100 qualification, fault reporting, or extended temperature validation is contractually required.

Compared with MP4558DN-LF, MP4571DN-LF offers higher current and synchronous rectification for better light-load efficiency, while LM5164QDDARQ1 adds automotive qualification at the cost of external FETs and increased design complexity-neither is pin-compatible, but both address distinct lifecycle or compliance requirements.

Availability

MP4558DN-LF is available at Aetrix Electronics and suitable for automotive body electronics, industrial PLC power distribution, and battery-backed telematics requiring stable component supply through extended product lifecycles.

Supply support for MP4558DN-LF 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, and global manufacturing partnerships.

The MP45xx series targets high-input-voltage DC/DC conversion for automotive, industrial, and telecom infrastructure, emphasizing integration, thermal robustness, and EMI resilience in compact packages.

FAQ

What does "NOT RECOMMENDED FOR NEW DESIGNS" mean for MP4558DN-LF?

This designation indicates MPS has released a functional successor (MP4571) with improved specifications-including 2A output, synchronous rectification, and lower quiescent current-and recommends it for all new projects. MP4558DN-LF remains fully supported for existing designs and legacy production, with no announced obsolescence date.

Can MP4558DN-LF operate reliably at 2MHz switching frequency?

Yes, but with layout constraints: the 100ns minimum on-time limits practical duty cycle at 2MHz (e.g., 55V→5V requires ~9% duty, feasible only if VIN stays ≥12V). External bootstrap diode addition is recommended per MPS AN-107 to ensure BST capacitor recharge at full 2MHz.

Is the SOIC8E package RoHS-compliant and lead-free?

Yes, MP4558DN-LF carries the "-LF" suffix confirming lead-free, RoHS-compliant construction per EU Directive 2011/65/EU. The exposed pad is nickel-palladium-gold plated, compatible with standard Pb-free reflow profiles (peak 260°C).

How does frequency fold-back improve reliability during short-circuit conditions?

During output short, MP4558DN-LF reduces switching frequency and lowers current limit to ~50% of nominal, decreasing average power dissipation in the internal MOSFET. This prevents thermal runaway and allows indefinite safe operation until fault removal-no latch-off or auto-restart required.

What is the maximum achievable output voltage accuracy over temperature and line/load?

Output voltage accuracy is dominated by the 0.800V ±2% (±16mV) internal reference and FB pin leakage (<1.0μA). With 1% resistors in the feedback divider, total output error remains within ±3% over -40°C to +125°C junction temperature and full line/load range.

Does MP4558DN-LF require an external bootstrap diode for SOIC8E layout?

An external bootstrap diode is not mandatory for SOIC8E at ≤1MHz, but strongly recommended at 2MHz-especially with high duty cycles-to guarantee BST capacitor recharge. MPS AN-107 specifies a 1N4148W or equivalent fast-switching diode connected from VIN to BST, improving reliability in high-frequency, high-VIN applications.

How does the COMP pin function differ from traditional voltage-mode controllers?

In MP4558DN-LF's current-mode architecture, COMP is the error amplifier output driving the current comparator threshold. Its voltage directly sets peak inductor current per cycle. Unlike voltage-mode, this provides inherent slope compensation, faster load transient response, and simplified loop compensation using only one RC network.

MP4558DN-LF Specifications

Product attributes: Attribute value

Manufacturer:: Monolithic Power Systems Inc.

Series:: -

Package/Case:: 8-SOIC (0.154", 3.90mm Width) Exposed Pad

Packaging:: Tube

Product Status:: Active

Function:: Step-Down

Output Configuration:: Positive

Topology:: Buck

Output Type:: Adjustable

Number of Outputs:: 1

Voltage - Input (Min):: 3.8V

Voltage - Input (Max):: 55V

Voltage - Output (Min/Fixed):: 0.8V

Voltage - Output (Max):: 52V

Current - Output:: 1A

Frequency - Switching:: Up to 2MHz

Synchronous Rectifier:: No

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

Grade:: -

Qualification:: -

Mounting Type:: Surface Mount

Supplier Device Package:: 8-SOIC-EP

MP4558DN-LF FAQ

1.How can I place an order for MP4558DN-LF through Aetrix?

Please submit a Request for Quotation (RFQ) for MP4558DN-LF 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 MP4558DN-LF reliable?

The price and inventory of MP4558DN-LF are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MP4558DN-LF is usually 5 days.

3.What payment methods are accepted for MP4558DN-LF?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MP4558DN-LF transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for MP4558DN-LF?

MP4558DN-LF orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your MP4558DN-LF 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 MP4558DN-LF?

For technical support, including MP4558DN-LF datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MP4558DN-LF requirements.

6.How does Aetrix verify that MP4558DN-LF is sourced from the original manufacturer or authorized distributors?

All MP4558DN-LF 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 MP4558DN-LF meets industry standards.

7.What is the process for return or replacement of MP4558DN-LF?

All MP4558DN-LF units undergo pre-shipment inspection (PSI). If there is an issue with MP4558DN-LF, 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 MP4558DN-LF part is unused and in its original packaging.

Return procedure for MP4558DN-LF:

1.Submit a request within 90 days.

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

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