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

Diodes Incorporated AP3503FMPTR-G1

Name: AP3503FMPTR-G1
Brand: Diodes Incorporated
SKU: AP3503FMPTR-G1
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: AP3503FMPTR-G1

Manufacturer:: Diodes Incorporated

Category:: Voltage Regulators - DC DC Switching Regulators

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

Datasheet:: AP3503FMPTR-G1.pdf

Description:: IC REG BUCK ADJ 3A 8SO

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Product details

Overview

AP3503FMPTR-G1 from BCD Semiconductor is a 340kHz fixed-frequency, current-mode synchronous buck DC-DC converter in PSOP-8 package, integrating low-R_DS(on) N-channel MOSFETs to deliver up to 3A output current with peak efficiency of 95% at 12V_IN/3.3V_OUT. It features programmable soft-start, over-voltage protection (OVP) triggered at 1.1V on FB, and thermal shutdown at 160°C - deployed in LCD TV power rails for stable 3.3V core supply.

For engineers reviewing the AP3503FMPTR-G1 datasheet, AP3503FMPTR-G1 pinout, AP3503FMPTR-G1 application, or AP3503FMPTR-G1 equivalent, key selection criteria include input voltage range (4.5–18V), fixed 340kHz switching frequency, current-mode control loop stability, PSOP-8 thermal resistance (θ_JA = 60°C/W), and integrated protection functions including UVLO (4.0V threshold), OVP, and OTP.

Technical Context

The AP3503FMPTR-G1 implements a current-mode PWM architecture with internal transconductance error amplifier (G_EA = 800 μA/V) and slope-compensated current comparator, enabling fast load transient response and cycle-by-cycle current limiting. Its oscillator operates at 340kHz (±18%) with short-circuit foldback to 90kHz.

Feedback regulation uses a precision 0.925V reference (±1.8% over temperature) sensed at the FB pin; output voltage is set via external resistor divider. The COMP pin provides access to the error amplifier output for loop compensation using an RC network to GND, supporting stable operation with 10μH inductors and ceramic output capacitors.

Key Specifications

Parameter	Value and Actual Design Meaning
Input Voltage Range	4.5V to 18V - supports wide-input industrial and consumer DC supplies including 5V, 12V, and 15V rails.
Switching Frequency	340kHz (typ.) - balances EMI performance and inductor size; enables use of compact 10μH shielded inductors.
Output Current	3A continuous - sufficient for powering SoC cores, DDR memory, and display logic in set-top boxes and digital photo frames.
Feedback Reference	0.925V ±1.8% - sets output voltage accuracy; 1.1V OVP threshold ensures safe rail shutdown during feedback fault.
High-Side R_DS(on)	100mΩ (typ., 25°C) - reduces conduction loss at full load; thermal derating modeled via θ_JA = 60°C/W.
Soft-Start Time	15ms with 0.1μF SS-to-GND capacitor - prevents inrush current into downstream capacitance during power-up.
UVLO Threshold	4.00V rising edge with 200mV hysteresis - ensures clean startup after input stabilization and avoids brown-out oscillation.

Pinout & Package

AP3503FMPTR-G1 is housed in a thermally enhanced PSOP-8 package with exposed pad (EP) for PCB-level heat dissipation. The 8-pin layout supports high-current routing and compact layout with dedicated bootstrap (BS), switch node (SW), and feedback (FB) pins.

Pin/Terminal	Circuit Role	Design Meaning
1 - BS	Bootstrap supply	Drives gate of internal high-side MOSFET via external bootstrap capacitor connected to SW; enables 100% duty cycle capability.
2 - IN	Main power input	Accepts 4.5–18V; requires local 10μF/25V ceramic input capacitor to suppress high-frequency ripple and supply transient current.
3 - SW	Power switch node	Connects to inductor and bootstrap capacitor; carries high di/dt switching current - must be routed with minimal loop area.
4 - GND	Analog/digital ground	Common return for power, feedback, and compensation; EP pad must be soldered to solid GND plane for thermal and noise control.
5 - FB	Voltage feedback sense	Monitors output via resistor divider; 0.925V reference enables precise V_OUT setting; 1.1V OVP triggers immediate shutdown.
6 - COMP	Error amplifier output	Loop compensation point - requires RC network to GND to stabilize phase margin; optional extra capacitor improves transient response.
7 - EN	Enable control	Digital ON/OFF control; 1.5V threshold with 350mV hysteresis; internal pull-up enables automatic start if left floating.
8 - SS	Soft-start timing	Capacitor-to-GND sets ramp time; 0.1μF yields 15ms; open-circuit disables soft-start for immediate regulation.

Key Features

Feature	Design Value
Integrated dual N-MOSFETs	100mΩ high-side + 100mΩ low-side R_DS(on) - eliminates external power switches and reduces BOM count and board space.
Current-mode control	Fast transient response with inherent cycle-by-cycle current limiting - maintains stability under dynamic load steps up to 3A.
Comprehensive protection suite	UVLO, OVP (1.1V FB), OTP (160°C), and short-circuit foldback (90kHz) - prevents damage during fault conditions without external circuitry.
Programmable soft-start	Capacitor-controlled ramp (15ms typical) - limits inrush current into 22μF output capacitance and avoids input droop.
PSOP-8 thermal design	Exposed pad + θ_JA = 60°C/W - enables 3A operation at 85°C ambient with 2-layer PCB and 1-in² copper pour under EP.

Applications

LCD TV Power Supply

Set-Top Box Core Rail

Use Scenario: Generating stable 3.3V supply for main SoC and HDMI interface circuitry in 32–55" LCD TVs.

IC Role / Device Role / Timing Role: Primary synchronous buck regulator stepping down 12V intermediate bus to 3.3V with tight load regulation (<±1.5% at 3A).

Use Value: 95% peak efficiency minimizes heatsink requirements; current-mode control maintains <50mV output deviation during 1.5A→3A load transients.

Use Scenario: Providing regulated 3.3V to MPEG decoder, tuner IC, and USB PHY in cable/satellite STBs.

IC Role / Device Role / Timing Role: Main DC-DC converter with enable-controlled power sequencing; EN pin synchronized to system reset signal.

Use Value: Programmable soft-start prevents brown-out of microcontroller during cold boot; UVLO ensures clean restart after AC dropout.

Portable DVD Player

Digital Photo Frame

Use Scenario: Converting single-cell Li-ion (4.2V max) or 5V USB input to 3.3V for video processor and SD card interface.

IC Role / Device Role / Timing Role: High-efficiency step-down regulator operating down to 4.5V input; supports battery-powered runtime extension.

Use Value: 1.4mA quiescent current extends standby time; thermal shutdown protects against enclosure overheating during extended playback.

Use Scenario: Delivering 3.3V to LCD controller, flash memory, and touch controller in wall-mounted or tabletop photo frames.

IC Role / Device Role / Timing Role: Always-on power stage with EN pin controlled by motion sensor; low-noise operation avoids display flicker.

Use Value: Fixed 340kHz frequency simplifies EMI filtering; FB OVP prevents damage to sensitive TFT bias circuitry during feedback disconnection.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
MP2307DN-LF-Z (Monolithic Power)	400kHz switching frequency, 3A rating, but lacks programmable soft-start and has higher R_DS(on) (120mΩ/150mΩ).	Requires external soft-start circuit for inrush control; less suitable for battery-powered devices needing precise startup timing.	Preferred where higher frequency allows smaller magnetics, and thermal margin permits higher conduction loss.
TPS5430DDAR (Texas Instruments)	3.5A rating, adjustable frequency (200–500kHz), but larger SO-8 package and no integrated low-side FET (external diode required).	Needs external Schottky diode and compensation components; increases solution size and cost vs. AP3503F's fully integrated PSOP-8.	Chosen when design requires adjustable frequency tuning or >3A headroom, accepting added complexity and footprint.

Compared with MP2307DN-LF-Z and TPS5430DDAR, the AP3503FMPTR-G1 delivers tighter output voltage accuracy (0.925V ref), lower thermal resistance in PSOP-8, and full protection integration - making it optimal for space-constrained consumer electronics requiring robust, turnkey 3A buck conversion.

Availability

AP3503FMPTR-G1 is available at Aetrix Electronics and suitable for LCD TV power supplies, set-top box core rails, and portable media player designs requiring stable component supply, RoHS-compliant green packaging, and tape-and-reel delivery for automated SMT assembly.

Supply support for AP3503FMPTR-G1 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

BCD Semiconductor Manufacturing Limited is a Shanghai-based analog and power IC designer specializing in high-performance, cost-optimized power management solutions for consumer and industrial markets.

The AP3503F belongs to BCD's AP3xxx synchronous buck converter product line, engineered for high-efficiency, low-BOM-count DC-DC conversion in space- and cost-sensitive consumer electronics such as displays and media players.

FAQ

What is the minimum input voltage required for reliable operation of AP3503FMPTR-G1?

The AP3503FMPTR-G1 specifies a minimum input voltage of 4.5V under recommended operating conditions. Its UVLO circuit disables the regulator below 3.65V (rising threshold) and re-enables only after crossing 4.00V with 200mV hysteresis, preventing unstable operation near dropout. Operation below 4.5V risks reduced output current capability and degraded regulation.

How does the COMP pin function in loop compensation?

The COMP pin is the output of the internal transconductance error amplifier and serves as the control node for the current-mode PWM comparator. A series RC network from COMP to GND sets dominant pole location for phase margin; adding a small capacitor (e.g., 1nF) directly to GND further attenuates high-frequency noise and improves transient recovery without compromising stability.

Can AP3503FMPTR-G1 drive a 5V output from a 12V input?

Yes - the AP3503FMPTR-G1 supports any output voltage ≥0.925V via external resistor divider on the FB pin. For 5V output, use R1 = 44.2kΩ and R2 = 10kΩ (V_OUT = 0.925 × (1 + R1/R2)). Ensure the feedback divider draws ≤100nA to avoid accuracy degradation, and verify thermal performance at full load due to increased duty cycle (~42%).

Is the exposed pad (EP) electrically connected internally?

No - the exposed pad on the PSOP-8 package is not internally connected to any die node; it is a thermal pad only. It must be soldered to a dedicated GND copper pour on the PCB for effective heat dissipation and EMI reduction, but no electrical connection (e.g., vias to internal GND planes) is required beyond thermal conduction.

AP3503FMPTR-G1 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):: 4.5V

Voltage - Input (Max):: 18V

Voltage - Output (Min/Fixed):: 0.925V

Voltage - Output (Max):: 16.2V

Current - Output:: 3A

Frequency - Switching:: 340kHz

Synchronous Rectifier:: Yes

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

Grade:: -

Qualification:: -

Mounting Type:: Surface Mount

Supplier Device Package:: 8-SO-EP

AP3503FMPTR-G1 FAQ

1.How can I place an order for AP3503FMPTR-G1 through Aetrix?

Please submit a Request for Quotation (RFQ) for AP3503FMPTR-G1 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 AP3503FMPTR-G1 reliable?

The price and inventory of AP3503FMPTR-G1 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for AP3503FMPTR-G1 is usually 5 days.

3.What payment methods are accepted for AP3503FMPTR-G1?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for AP3503FMPTR-G1 transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for AP3503FMPTR-G1?

AP3503FMPTR-G1 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your AP3503FMPTR-G1 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 AP3503FMPTR-G1?

For technical support, including AP3503FMPTR-G1 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your AP3503FMPTR-G1 requirements.

6.How does Aetrix verify that AP3503FMPTR-G1 is sourced from the original manufacturer or authorized distributors?

All AP3503FMPTR-G1 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 AP3503FMPTR-G1 meets industry standards.

7.What is the process for return or replacement of AP3503FMPTR-G1?

All AP3503FMPTR-G1 units undergo pre-shipment inspection (PSI). If there is an issue with AP3503FMPTR-G1, 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 AP3503FMPTR-G1 part is unused and in its original packaging.

Return procedure for AP3503FMPTR-G1:

1.Submit a request within 90 days.

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

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