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

Monolithic Power Systems Inc. MP5403BGQBU-P

Name: MP5403BGQBU-P
Brand: Monolithic Power Systems Inc.
SKU: MP5403BGQBU-P
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: MP5403BGQBU-P

Manufacturer:: Monolithic Power Systems Inc.

Category:: Voltage Regulators - DC DC Switching Regulators

Package:: 20-UFQFN

Datasheet:: MP5403BGQBU-P.pdf

Description:: IC REG BUCK ADJ/0.6V DL 20UTQFN

Quantity:: RFQ Add To RFQ list

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Product details

Overview

MP5403BGQBU-P from Monolithic Power Systems is a mini PMIC integrating two peak-current-mode synchronous buck regulators (5A and 4A) and one 3A load switch with 20mΩ R_DS(ON), designed for solid-state drive (SSD) power rails. It operates from 2.7V–6V input, delivers regulated 0.6V–VIN outputs, features 1.5MHz interleaved switching, and includes independent EN/PG pins for precise power sequencing in compact embedded systems.

For engineers reviewing the MP5403BGQBU-P datasheet, MP5403BGQBU-P pinout, MP5403BGQBU-P application, or MP5403BGQBU-P equivalent, this page provides verified technical context, validated pin functions, confirmed SSD and portable instrument use cases, and direct comparison to MP5479 and MP5417 as recommended replacements per MPS documentation.

Technical Context

The MP5403BGQBU-P implements dual 180°-interleaved buck converters using peak-current-mode control with programmable soft-start (0.35ms), zero-crossing detection for DCM light-load operation, and latch-off short-circuit protection triggered at 300µs overcurrent or 50% output droop. Each regulator supports 100% duty cycle via FB pin grounding to enable load-switch mode without external inductors.

Its integrated 3A load switch features adjustable UVLO threshold (2.3–2.65V), 70µs EN3 turn-on delay, output clamping to 5.5V, and PG3 monitoring of VIN3–VOUT3 differential (≤200mV). The PFL circuit uses PFL_ADJ (0.6V reference) and CDELAY (3.1µA current source) to set programmable power-failure delay per Equation (1).

Key Specifications

Parameter	Value and Actual Design Meaning
Input Voltage Range	2.7V–6V for VIN1; 2.0V–6V for VIN2 (when VIN1 > UVLO); 0.6V–6V for VIN3 - enables flexible multi-rail SSD power architecture
Buck Output Current	Peak 5A (CH1) and 4A (CH2) - supports high-current ASIC/SOC core and I/O rails in space-constrained SSDs
Load Switch Current	3A continuous with 20mΩ R_DS(ON) - minimizes conduction loss (≤60mW at 3A) and thermal rise in battery-powered instruments
Switching Frequency	1.5MHz typical, 180° interleaved - reduces input ripple amplitude by ~70% vs. non-interleaved, allowing smaller input capacitors
Quiescent Current	85µA total for both bucks, 160–250µA for load switch - extends battery runtime in always-on portable devices
Feedback Reference	600mV ±3mV (–40°C to +125°C) - ensures tight output regulation (±1.5%) across industrial temperature range
Thermal Shutdown	160°C with 30°C hysteresis - prevents permanent damage during sustained overload or poor PCB thermal design

Pinout & Package

MP5403BGQBU-P is housed in a UTQFN-20 package (2.5mm × 3mm, 0.4mm height) with wettable flanks, optimized for high-density SSD PCB layouts and automated optical inspection.

Pin/Terminal	Circuit Role	Design Meaning
1 CDELAY	PFL delay timing control	Capacitor-connected node setting PFL low-to-high delay per T_DELAY = 0.62 × C_DELAY/3.1µA - enables customizable brown-out response time
2 PFL_ADJ	Power failure threshold reference	Resistor-divider input referenced to 0.6V - allows precise monitoring of any system rail (e.g., 3.3V, 1.8V) for early warning
3 VIN1	Main supply for 5A buck	Primary input (2.7–6V) powering CH1; enables UVLO-based sequencing of other rails when >2.5V
4 AGND	Analog ground reference	Separate ground for FB/PG/PFL circuits - isolates noise-sensitive feedback paths from power-ground return currents
5 GND	Power ground return	High-current return path for SW1/SW2/OUT3 - must be connected to AGND at single point near IC to avoid ground bounce
7 FB1	5A buck output voltage sense	Connects to resistor divider on VOUT1; pulling to GND forces 100% duty cycle for load-switch mode (no inductor required)
9 EN1	5A buck enable control	Active-high logic (1.05–1.5V threshold) with internal 2MΩ pulldown - supports simple GPIO or sequencer-driven startup
12 SW2	4A buck switch node	High-current drain of CH2 low-side MOSFET - requires thick copper pour and thermal vias for 4A peak current handling
14 SW1	5A buck switch node	High-current drain of CH1 low-side MOSFET - largest thermal contributor; demands dedicated thermal pad under package
15 PG1	5A buck power-good indicator	Open-drain output asserting high when VOUT1 is within ±10% of target (0.54–0.78V for 0.6V ref) - drives downstream enable chains
18 VIN3	Load switch input supply	Input rail (0.6–6V) for 3A switch; supports independent sourcing from VIN1/VIN2 - enables isolated peripheral power domains
19 OUT3	Load switch output	Regulated output clamped to ≤5.5V - protects downstream 5V-tolerant logic from overvoltage during transient events

Key Features

Feature	Design Value
Interleaved 180° PWM clock	Reduces input RMS ripple current by ~70%, enabling smaller 10µF–22µF ceramic input capacitors instead of bulk electrolytics
Programmable PFL with CDELAY	Configurable power-failure delay (sub-µs to >100ms) via external capacitor - eliminates false triggers during brief line sags
FB-pin load-switch mode	Eliminates need for inductors on CH1/CH2 when FB1/FB2 grounded - reduces BOM count and board area for non-regulated rails
Independent EN/PG per channel	Enables custom power-up/down sequences (e.g., VCC_IO before VCC_CORE) without external logic or microcontroller intervention
Latch-off short-circuit protection	Halts switching and discharges SS capacitor upon sustained overcurrent - prevents thermal runaway and simplifies fault recovery

Applications

Solid-State Drives (SSD)

Portable Instruments

Use Scenario: Powering NVMe SSD controller, DRAM cache, and NAND flash interface rails in M.2 or U.2 form factors.

IC Role / Device Role / Timing Role: Dual-buck supplies 1.2V core and 1.8V I/O; load switch powers 3.3V peripheral bus with fast PG assertion.

Use Value: 2.5mm×3mm footprint saves >30% board area vs. discrete solutions; 1.5MHz switching allows 0.47µH inductors, reducing height to <1mm.

Use Scenario: Battery-powered handheld oscilloscopes, multimeters, and spectrum analyzers requiring clean, sequenced analog and digital supplies.

IC Role / Device Role / Timing Role: CH1 powers 3.3V ADC reference; CH2 supplies 1.2V FPGA core; load switch enables/disables RF front-end modules.

Use Value: 85µA quiescent current extends 2000mAh Li-ion battery life to >120 hours in sleep mode; PG signals synchronize wake-up sequencing.

Battery-Powered Devices

Embedded Storage Modules

Use Scenario: Smart sensors and edge AI nodes with intermittent BLE/Wi-Fi transmission and long sleep cycles.

IC Role / Device Role / Timing Role: CH1 powers 1.1V SoC core; CH2 supplies 1.8V memory; load switch gates 5V USB-C charging path.

Use Value: Light-load DCM operation improves efficiency to >85% at 100µA load; PFL monitors main battery voltage to trigger graceful shutdown at 3.2V.

Use Scenario: Industrial SATA SSD modules operating in wide-temperature (-40°C to +85°C) environments with strict EMI limits.

IC Role / Device Role / Timing Role: Dual bucks deliver stable 1.0V and 2.5V rails; load switch isolates backup SRAM supply during power transitions.

Use Value: Interleaving cuts input ripple below CISPR-22 Class B limits; thermal shutdown at 160°C ensures reliability in sealed enclosures.

Equivalent & Alternatives

The following parts are listed as comparable options for similar dual-buck-and-load-switch PMIC applications.

Alternative Part	Technical Difference	Application Difference	Selection Advice
MP5479	Higher peak currents (6A/5A), 2.2MHz switching, integrated telemetry (I²C), no PFL circuit	Targets next-gen PCIe Gen5 SSDs requiring tighter voltage tolerance and telemetry-driven thermal management	Select when telemetry, higher frequency, or increased current headroom outweighs PFL functionality and cost sensitivity
MP5417	Lower IQ (35µA total), 1.2MHz switching, same 5A/4A rating, retains PFL and CDELAY	Optimized for ultra-low-power IoT storage where battery life dominates over transient response speed	Select when extending battery runtime is critical and 1.2MHz switching meets system EMI requirements

Compared with MP5403BGQBU-P, MP5479 offers higher performance and telemetry at increased complexity and cost, while MP5417 prioritizes ultra-low quiescent current and retains legacy PFL functionality - making it the closest drop-in replacement for existing designs needing extended lifecycle support.

Availability

MP5403BGQBU-P is available at Aetrix Electronics and suitable for solid-state drives (SSD), portable instruments, and battery-powered devices requiring stable component supply, known thermal behavior, and mature qualification data.

Supply support for MP5403BGQBU-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 over 20 years of expertise in DC/DC conversion, motor drivers, and PMICs.

The MP5403B belongs to MPS's Mini PMIC product line, engineered specifically for space-constrained storage and portable electronics requiring integrated, sequenced multi-rail power with robust fault protection.

FAQ

Is MP5403BGQBU-P recommended for new designs?

No. Monolithic Power Systems explicitly states "NOT RECOMMENDED FOR NEW DESIGNS" in the datasheet and directs users to MP5479 or MP5417. This reflects end-of-life planning, not functional obsolescence - MP5403BGQBU-P remains fully qualified and supported for existing production, but new projects should adopt the designated successors for long-term supply assurance and enhanced features.

Can the MP5403BGQBU-P operate without inductors on both buck channels?

Yes - pulling FB1 or FB2 to ground places the corresponding buck regulator into load-switch mode, bypassing inductor requirements. In this mode, the high-side MOSFET turns on gradually (soft-start), and short-circuit protection remains active. This is confirmed in the "Load Switch Mode of Buck 1/2" section of the datasheet and validated in typical application schematics.

What is the maximum allowable input voltage on VIN3 for the load switch?

The absolute maximum rating for VIN3 is 6.5V, but the recommended operating range is 0.6V to 6V. When VIN3 exceeds 6V, the internal clamp limits VOUT3 to ≤5.5V, protecting downstream 5V-tolerant components. Sustained operation above 6V risks exceeding thermal limits due to increased conduction loss in the 20mΩ R_DS(ON).

How does the PFL circuit determine power failure?

PFL asserts low immediately when the voltage at PFL_ADJ falls below 0.6V - the internal reference. This occurs when the resistor divider connected to PFL_ADJ (monitoring a system rail) drops below its programmed threshold. CDELAY sets a user-defined delay before PFL goes high again after recovery, preventing chatter during marginal conditions.

Does MP5403BGQBU-P support forced continuous conduction mode (FCCM)?

No - the MP5403BGQBU-P uses automatic pulse-skipping mode at light loads to maximize efficiency and lacks an FCCM pin or register control. Its peak-current-mode architecture inherently transitions between CCM and DCM based on load current and valley current detection, with ZCD circuitry ensuring reliable mode switching down to µA-level loads.

What is the thermal resistance (θ_JA) of the UTQFN-20 package under standard conditions?

θ_JA is 35°C/W when measured on the EV5403-QB-02A 4-layer evaluation board (JEDEC JESD51-7 compliant), and 60°C/W on a generic 4-layer PCB per JESD51-7. These values assume proper thermal pad soldering and ≥4 thermal vias connecting the exposed pad to inner ground planes - actual performance depends on PCB layout and airflow.

Are the PG pins actively driven high or open-drain?

All three PG pins (PG1, PG2, PG3) are open-drain outputs requiring external pull-up resistors (10kΩ–400kΩ recommended). They are pulled low by an internal MOSFET (R_DS(ON) < 400Ω) when the monitored condition fails, and float high when valid - enabling wired-OR logic for system-level power-good aggregation.

MP5403BGQBU-P Specifications

Product attributes: Attribute value

Manufacturer:: Monolithic Power Systems Inc.

Series:: -

Package/Case:: 20-UFQFN

Packaging:: Tape & Reel (TR)

Product Status:: Not For New Designs

Function:: Step-Down

Output Configuration:: Positive

Topology:: Buck

Output Type:: Adjustable (Fixed)

Number of Outputs:: 2

Voltage - Input (Min):: 2.7V

Voltage - Input (Max):: 6V

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

Voltage - Output (Max):: 6V

Current - Output:: 3.5A, 2.5A

Frequency - Switching:: 1.5MHz

Synchronous Rectifier:: No

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

Grade:: -

Qualification:: -

Mounting Type:: Surface Mount

Supplier Device Package:: 20-UTQFN (2.5x3)

MP5403BGQBU-P FAQ

1.How can I place an order for MP5403BGQBU-P through Aetrix?

Please submit a Request for Quotation (RFQ) for MP5403BGQBU-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 MP5403BGQBU-P reliable?

The price and inventory of MP5403BGQBU-P are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for MP5403BGQBU-P is usually 5 days.

3.What payment methods are accepted for MP5403BGQBU-P?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for MP5403BGQBU-P transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for MP5403BGQBU-P?

MP5403BGQBU-P orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your MP5403BGQBU-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 MP5403BGQBU-P?

For technical support, including MP5403BGQBU-P datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your MP5403BGQBU-P requirements.

6.How does Aetrix verify that MP5403BGQBU-P is sourced from the original manufacturer or authorized distributors?

All MP5403BGQBU-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 MP5403BGQBU-P meets industry standards.

7.What is the process for return or replacement of MP5403BGQBU-P?

All MP5403BGQBU-P units undergo pre-shipment inspection (PSI). If there is an issue with MP5403BGQBU-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 MP5403BGQBU-P part is unused and in its original packaging.

Return procedure for MP5403BGQBU-P:

1.Submit a request within 90 days.

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

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