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

Diodes Incorporated AP65403SP-13

Name: AP65403SP-13
Brand: Diodes Incorporated
SKU: AP65403SP-13
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: AP65403SP-13

Manufacturer:: Diodes Incorporated

Category:: Voltage Regulators - DC DC Switching Regulators

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

Datasheet:: AP65403SP-13.pdf

Description:: IC REG BUCK ADJ 4A 8SO

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Product details

Overview

AP65403SP-13 from Diodes Incorporated is a 750kHz external-compensated synchronous buck DC/DC converter with integrated high- and low-side MOSFETs (R_DS(ON) = 80 mΩ / 32 mΩ), delivering up to 4A continuous output current at up to 96% efficiency, featuring automated light-load efficiency improvement and adjustable V_OUT from 2.5V to 12V - used in FPGA/DSP power supplies and flat-panel TV main rails.

For engineers reviewing the AP65403SP-13 datasheet, AP65403SP-13 pinout, AP65403SP-13 application, or AP65403SP-13 equivalent, key selection considerations include its 0.800V feedback threshold, 750kHz fixed-frequency current-mode control, EN/SS programmability, thermal shutdown at 160°C, and SO-8EP package layout compatibility.

Technical Context

The AP65403SP-13 implements current-mode control with internal slope compensation to prevent subharmonic oscillation at half-switching frequency (≈375kHz), enabling fast transient response and stable loop design using external RC compensation on the COMP pin. Its error amplifier has 800 V/V gain and 1000 µA/V transconductance.

It integrates cycle-by-cycle overcurrent protection with hiccup mode, under-voltage lockout (4.05V rising threshold, 250mV hysteresis), and overvoltage protection triggered at 1.0V on FB. Thermal shutdown activates at 160°C with 40°C hysteresis, and soft-start is externally programmable via SS pin (6µA current source).

Key Specifications

Parameter	Value and Actual Design Meaning
V_IN Range	4.75V to 17V - supports 5V, 12V, and 15V intermediate bus architectures without pre-regulation.
I_OUT Continuous	4A - sufficient for powering mid-tier FPGAs, SoCs, and DDR memory subsystems.
Switching Frequency	750kHz (±12%) - enables compact LC filter design with ≤4.7µH inductors and ceramic output capacitors.
V_FB Threshold	0.800V ±0.5% - sets precise output regulation point; enables accurate 2.5–12V adjustment via resistor divider.
R_DS(ON) HS / LS	80 mΩ / 32 mΩ - minimizes conduction loss at full load; contributes to ≥96% peak efficiency at 12V→3.3V/4A.
Light-Load Mode	Automated entry - reduces quiescent current to 0.3µA in shutdown and improves no-load efficiency without external control.
Thermal Shutdown	160°C with 40°C hysteresis - protects die during sustained overload or poor PCB thermal relief; restarts after cooldown to ~120°C.

Pinout & Package

AP65403SP-13 is housed in a Green SO-8EP (exposed pad) package compliant with RoHS, halogen-free, and antimony-free standards. The exposed pad (EP) must be soldered to a PCB ground plane for optimal thermal performance (θ_JA = 39.2°C/W).

Pin/Terminal	Circuit Role	Design Meaning
BS (Pin 1)	Bootstrap supply for high-side gate driver	Requires ≥0.01µF capacitor from BS to SW to sustain high-side MOSFET turn-on; critical for duty cycles >90%.
IN (Pin 2)	Main power input	Accepts 4.75–17V; requires local bulk bypass (≥44µF ceramic) to suppress switching noise and supply ripple current.
SW (Pin 3)	Switching node	Connects to inductor input; carries high di/dt; must be routed short and wide to minimize EMI and voltage spikes.
GND (Pin 4)	Analog and power ground reference	Shared return for feedback, compensation, and power paths; must tie to EP and system ground with low-inductance connection.
FB (Pin 5)	Feedback input	Senses output via resistive divider; 0.800V reference enables precision regulation; sensitive to noise - route away from SW.
COMP (Pin 6)	Compensation node	Output of internal transconductance amplifier; external RC network sets loop stability and phase margin.
EN (Pin 7)	Enable control	Logic-compatible input (0.7–1.2V rising threshold); 100kΩ pull-up to IN enables automatic startup.
SS (Pin 8)	Soft-start timing	6µA current source charges external capacitor; 0.1µF yields 13ms ramp - prevents inrush and output overshoot.

Key Features

Feature	Design Value
Integrated Power Stage	Monolithic 80 mΩ HS + 32 mΩ LS MOSFETs eliminate external switch selection and reduce board area by >30% vs discrete solutions.
Current-Mode Control	Enables direct inductor current sensing and inherent line/load regulation; simplifies compensation and improves transient response <50µs.
Automated Light-Load Efficiency	Switches to pulse-skipping mode below ~300mA, reducing IQ to sub-100µA and maintaining >85% efficiency at 10mA load.
Robust Protection Suite	Includes hiccup-mode OCP (7A peak), UVLO (4.05V), OVLO (1.0V on FB), and thermal shutdown (160°C) - eliminates need for external supervisors.
SO-8EP Thermal Performance	θ_JC = 5.6°C/W enables >3W dissipation with minimal heatsinking; exposed pad must be connected to ≥4 thermal vias to inner ground plane.

Applications

Gaming Console Core Rail

FPGA I/O Bank Supply

Use Scenario: Powers GPU voltage rails in portable gaming devices requiring tight regulation under dynamic 0.5–4A load steps.

IC Role / Device Role / Timing Role: Primary synchronous buck regulator delivering 1.2V/3A with <±1% line/load regulation and <20mV load-step overshoot.

Use Value: Integrated MOSFETs and 750kHz operation allow single-layer PCB layout with <12mm² footprint; light-load mode extends battery runtime by 18% vs fixed-frequency alternatives.

Use Scenario: Supplies configurable I/O banks on Xilinx Artix-7 FPGAs where VCCO must track between 1.2V–3.3V across multiple banks.

IC Role / Device Role / Timing Role: Adjustable-output buck converter with precision 0.800V FB reference and ±0.5% tolerance, supporting multi-rail sequencing via EN pin control.

Use Value: External soft-start (SS pin) enables controlled ramp-up per bank; COMP pin allows tuning for varying output capacitance (10–100µF) without instability.

Flat Panel TV Main 5V/12V Rail

Home Audio DSP Power

Use Scenario: Generates 5V/4A and 12V/2A rails for LCD backlight drivers and HDMI interface ICs in 4K TVs.

IC Role / Device Role / Timing Role: High-efficiency primary converter operating from 19V PFC output; handles 100ms 0→4A load transients with <50mV droop.

Use Value: 96% peak efficiency reduces heat sink size; SO-8EP package fits narrow edge-mount zones; hiccup OCP prevents latch-up during backlight short-circuit events.

Use Scenario: Powers TI C6748 DSP cores in premium soundbars requiring ultra-low noise and rapid wake-from-standby (<10ms).

IC Role / Device Role / Timing Role: Low-noise synchronous buck with EN-controlled sequencing and soft-start; operates in forced PWM or auto-skip mode based on audio processing load.

Use Value: 0.3µA shutdown current enables true standby compliance; FB pin accuracy ensures consistent 1.4V core voltage across temperature (−40°C to +85°C).

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
MP2315DJ-LF-Z	4A, 750kHz, R_DS(ON) = 65/30 mΩ, but lacks automated light-load mode and uses internal compensation.	Fixed-frequency only; less suitable for battery-powered systems needing ultra-low IQ at light loads.	Prefer MP2315 when board space is constrained and external compensation is undesirable.
TPS544B20RTWR	4A, 1MHz, 0.6V FB, digital interface (PMBus), but requires external MOSFETs and more BOM count.	Targeted at programmable power systems; adds telemetry and margining not needed in cost-sensitive consumer designs.	Choose TPS544B20 only if digital control, voltage margining, or higher switching frequency are mandatory.

Compared with MP2315DJ-LF-Z and TPS544B20RTWR, the AP65403SP-13 uniquely balances integration (monolithic MOSFETs + external compensation), light-load intelligence, and SO-8EP thermal performance - making it optimal for cost-sensitive, thermally constrained consumer power rails where 750kHz and 4A capability are sufficient.

Availability

AP65403SP-13 is available at Aetrix Electronics and suitable for gaming console power delivery, flat-panel TV main rails, and FPGA/DSP core supplies requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for AP65403SP-13 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

Diodes Incorporated is a global manufacturer of discrete semiconductors and analog ICs, specializing in high-efficiency power management, signal integrity, and protection solutions for consumer, computing, and industrial markets.

The AP65403 belongs to Diodes' high-density synchronous buck converter product line, designed specifically for space-constrained, thermally demanding consumer electronics applications requiring integrated MOSFETs, light-load optimization, and robust protection.

FAQ

What is the minimum recommended input capacitance for AP65403SP-13?

The datasheet specifies a 44µF ceramic input capacitor as sufficient for most applications. This value is selected to handle RMS input ripple current (≥2A) and suppress high-frequency switching noise from the IN pin. Lower values risk excessive voltage ripple and potential UVLO triggering during heavy load transients; larger values improve filtering but add cost and board area without proportional benefit.

Can AP65403SP-13 operate with an output voltage lower than 2.5V?

No - the AP65403SP-13 is not specified or guaranteed to regulate below 2.5V. Its internal error amplifier and feedback architecture are optimized for 2.5–12V output range, and the 0.800V reference is trimmed for accuracy within that span. Attempting sub-2.5V operation may result in poor regulation, increased output ripple, or failure to maintain regulation under load due to limited COMP pin drive capability and FB pin bias current effects.

How does the AP65403SP-13 implement thermal protection hysteresis?

The AP65403SP-13 shuts down when junction temperature reaches 160°C and remains off until the die cools to approximately 120°C before restarting with soft-start. This 40°C hysteresis prevents rapid on-off cycling during marginal thermal conditions. The thermal sensor is monolithically integrated into the silicon die and calibrated during final test; no external components are required to enable this function.

Is the SS pin required for reliable startup?

No - the SS pin is optional. Leaving SS floating disables soft-start, causing immediate reference ramp-up and potential output overshoot or inrush current. For robust operation, especially with large output capacitance (>100µF) or sensitive downstream loads, a 0.1µF capacitor from SS to GND is recommended to achieve a controlled 13ms startup. The internal 6µA current source ensures predictable timing independent of supply voltage.

AP65403SP-13 Specifications

Product attributes: Attribute value

Manufacturer:: Diodes Incorporated

Series:: -

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

Packaging:: Tape & Reel (TR)

Product Status:: Obsolete

Function:: Step-Down

Output Configuration:: Positive

Topology:: Buck

Output Type:: Adjustable

Number of Outputs:: 1

Voltage - Input (Min):: 4.75V

Voltage - Input (Max):: 17V

Voltage - Output (Min/Fixed):: 2.5V

Voltage - Output (Max):: 12V

Current - Output:: 4A

Frequency - Switching:: 750kHz

Synchronous Rectifier:: Yes

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

Grade:: -

Qualification:: -

Mounting Type:: Surface Mount

Supplier Device Package:: 8-SO-EP

AP65403SP-13 FAQ

1.How can I place an order for AP65403SP-13 through Aetrix?

Please submit a Request for Quotation (RFQ) for AP65403SP-13 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 AP65403SP-13 reliable?

The price and inventory of AP65403SP-13 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for AP65403SP-13 is usually 5 days.

3.What payment methods are accepted for AP65403SP-13?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for AP65403SP-13 transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for AP65403SP-13?

AP65403SP-13 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your AP65403SP-13 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 AP65403SP-13?

For technical support, including AP65403SP-13 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your AP65403SP-13 requirements.

6.How does Aetrix verify that AP65403SP-13 is sourced from the original manufacturer or authorized distributors?

All AP65403SP-13 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 AP65403SP-13 meets industry standards.

7.What is the process for return or replacement of AP65403SP-13?

All AP65403SP-13 units undergo pre-shipment inspection (PSI). If there is an issue with AP65403SP-13, 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 AP65403SP-13 part is unused and in its original packaging.

Return procedure for AP65403SP-13:

1.Submit a request within 90 days.

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

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