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

Diodes Incorporated AP3503EMPTR-G1

Name: AP3503EMPTR-G1
Brand: Diodes Incorporated
SKU: AP3503EMPTR-G1
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: AP3503EMPTR-G1

Manufacturer:: Diodes Incorporated

Category:: Voltage Regulators - DC DC Switching Regulators

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

Datasheet:: AP3503EMPTR-G1.pdf

Description:: IC REG BUCK ADJ 3A 8SO

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Product details

Overview

AP3503EMPTR-G1 from Diodes Incorporated is a 340kHz fixed-frequency, current-mode PWM synchronous buck DC-DC converter in PSOP-8 package, delivering up to 3A output current with peak efficiency of 95% across 4.5V–18V input range. It integrates low-R_DS(on) N-channel MOSFETs, supports programmable soft-start, and provides hiccup-mode short-circuit protection, overvoltage/undervoltage lockout, and thermal shutdown - deployed in LCD TV power rails.

For engineers reviewing the AP3503EMPTR-G1 datasheet, AP3503EMPTR-G1 pinout, AP3503EMPTR-G1 application, or AP3503EMPTR-G1 equivalent, key selection criteria include its 340kHz switching frequency, 0.925V feedback reference voltage, 100mΩ high-side/low-side R_DS(on), 15ms soft-start time with 0.1μF capacitor, and PSOP-8 thermal pad layout requirements.

Technical Context

This IC implements current-mode control with cycle-by-cycle current limiting and fast transient response, using an internal transconductance error amplifier (800μA/V) and slope-compensated PWM comparator. The oscillator operates at 340kHz under normal conditions and drops to 90kHz during short-circuit events for hiccup-mode recovery.

The functional block includes integrated high-side and low-side power MOSFETs, bootstrap-driven gate drive for the high-side switch, and dedicated pins for loop compensation (COMP), voltage feedback (FB), enable control (EN), and soft-start timing (SS). Protection logic triggers shutdown at +160°C with 20°C hysteresis and disables operation below 3.65V input (UVLO).

Key Specifications

Parameter	Value and Actual Design Meaning
Switching Frequency	340kHz fixed - enables compact magnetics and predictable EMI profile
Output Current	3A continuous - supports mid-power applications like set-top box core rails
Input Voltage Range	4.5V to 18V - compatible with 5V, 12V, and 15V intermediate bus architectures
Feedback Reference	0.925V ±1.8% - sets output voltage via external resistor divider (e.g., 3.3V with 26.1k/13k)
Efficiency Peak	95% - achieved at medium load with 12V input → 3.3V output using 10μH inductor
R_DS(on) (HS/LS)	100mΩ each - reduces conduction loss and improves light-load efficiency
Soft-Start Time	15ms with 0.1μF SS-to-GND capacitor - prevents inrush current during power-up

Pinout & Package

AP3503EMPTR-G1 is housed in a thermally enhanced PSOP-8 package with exposed pad (EP) requiring PCB connection to GND for optimal thermal performance (θ_JA = 60°C/W). Pin assignments are validated per Diodes DS41539 Rev. 3–4.

Pin/Terminal	Circuit Role	Design Meaning
1 BS	Bootstrap supply	Drives high-side MOSFET gate via external capacitor between BS and SW; enables 100% duty cycle capability
2 IN	Main power input	Accepts 4.5–18V; requires local ceramic bypass capacitor to suppress high-frequency noise
3 SW	Power switch node	Connects to inductor and bootstrap capacitor; carries high di/dt switching current
4 GND	Analog/digital ground	Reference for FB, COMP, EN, SS; must be low-impedance and tied to EP for thermal stability
5 FB	Voltage feedback input	Senses output via resistive divider; trips OVP at 1.1V and enters SCP mode below 0.3V
6 COMP	Loop compensation node	Output of error amplifier; connects to RC network for Type II/III compensation
7 EN	Enable control	Digital input: >1.5V enables regulator; <1.1V disables; 100kΩ pull-up ensures startup
8 SS	Soft-start timing	Current source charges external capacitor; 0.1μF yields 15ms ramp; open = disabled
EP	Exposed thermal pad	Must be soldered to GND plane for thermal dissipation and EMI reduction

Key Features

Feature	Design Value
Current-mode PWM control	Enables stable operation with fast load transient response and inherent cycle-by-cycle current limiting
Hiccup-mode short-circuit protection	Reduces power dissipation during sustained overload by pulsing ON/OFF instead of latching off
Integrated 100mΩ HS/LS MOSFETs	Eliminates external power switches and associated gate drivers, reducing BOM count and layout area
Programmable soft-start	Prevents output overshoot and limits input inrush by controlling FB reference ramp rate
Thermal shutdown with hysteresis	Shuts down at +160°C and re-enables only after cooling to +140°C, preventing thermal cycling damage

Applications

LCD TV Power Supply

Set-Top Box Core Rail

Use Scenario: Provides stable 3.3V rail for main SoC and video processing ICs in 32–55" LCD TVs.

IC Role / Device Role / Timing Role: Primary synchronous buck regulator converting 12V intermediate bus to 3.3V system rail.

Use Value: High 95% efficiency minimizes heatsink requirements; hiccup-mode SCP protects against panel backlight fault conditions.

Use Scenario: Powers MPEG decoder, tuner, and HDMI interface in cable/satellite STBs operating from 12V wall adapter.

IC Role / Device Role / Timing Role: Step-down regulator with tight line/load regulation (<±1%) for noise-sensitive AV subsystems.

Use Value: 0.925V precision feedback reference ensures accurate 3.3V output; PSOP-8 EP improves thermal margin in sealed enclosures.

Portable DVD Player

Digital Photo Frame

Use Scenario: Generates 3.3V logic supply from single-cell Li-ion (4.2V max) or 5V USB input in portable DVD players.

IC Role / Device Role / Timing Role: Buck converter supporting wide-input operation (4.5–18V) with light-load efficiency optimization.

Use Value: Maintains >85% efficiency at 10mA load, extending battery runtime; UVLO prevents brownout operation below 3.65V.

Use Scenario: Supplies 3.3V to display controller and flash memory in wall-mounted digital photo frames powered from 12V AC/DC adapter.

IC Role / Device Role / Timing Role: Compact, thermally robust DC-DC solution replacing linear regulators to reduce heat in enclosed plastic housing.

Use Value: PSOP-8 exposed pad lowers junction temperature rise by ~25°C vs. SO-8; EN pin enables remote power sequencing.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
AP62300WU-7	Higher 2.2MHz switching frequency, 6A output, smaller 2mm×2mm WLCSP package, no exposed pad	Better suited for space-constrained, high-density designs requiring faster transient response	Select when board area is critical and input voltage ≤17V; verify thermal design without EP
MP2315DJ-LF-Z	3.3A rating, 500kHz frequency, 0.8V reference, different pinout (no BS pin), no hiccup-mode SCP	Lacks bootstrap architecture and hiccup protection; uses external high-side driver	Choose only if existing layout accommodates non-PSOP-8 footprint and hiccup protection is not required

Compared with AP62300WU-7 and MP2315DJ-LF-Z, AP3503EMPTR-G1 offers proven thermal reliability via PSOP-8 EP, deterministic 340kHz EMI behavior, and robust hiccup-mode fault handling - making it preferable for cost-sensitive, thermally demanding consumer power supplies where long-term availability is managed via Aetrix lifecycle coordination.

Availability

AP3503EMPTR-G1 is available at Aetrix Electronics and suitable for LCD TV, set-top box, and portable DVD power supply designs requiring stable component supply and legacy design continuity.

Supply support for AP3503EMPTR-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

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

The AP3503E belongs to Diodes' synchronous buck regulator product line, designed specifically for cost-effective, high-efficiency mid-power DC-DC conversion in consumer electronics with strict thermal and reliability requirements.

FAQ

What is the recommended minimum output capacitance for AP3503EMPTR-G1?

The datasheet specifies 22μF (25V) as the minimum bulk output capacitance, using low-ESR ceramic or polymer types. This value ensures stable loop response and limits output ripple to <10mV_p-p at 3A load. Lower capacitance may cause instability or excessive ripple, especially with high ESR electrolytics.

Can AP3503EMPTR-G1 operate with input voltage below 4.5V?

No - the absolute minimum input voltage is 4.5V per Recommended Operating Conditions. Below this, UVLO prevents startup, and operation below 3.65V (UVLO threshold) forces shutdown. Attempting sub-4.5V operation risks erratic regulation or failure to initiate switching.

Is the exposed pad (EP) electrically connected to GND internally?

Yes - the EP is internally tied to the substrate GND and must be soldered to a PCB GND plane. It serves both thermal dissipation (θ_JA = 60°C/W) and EMI suppression. Leaving it unconnected degrades thermal performance by >30°C and increases radiated emissions.

How does the short-circuit protection behave during sustained overload?

Under sustained short-circuit, AP3503EMPTR-G1 enters hiccup mode: it shuts down for ~10ms, then attempts restart. If fault persists, it repeats the cycle. This limits average power dissipation to <1W, preventing thermal runaway while allowing automatic recovery once the fault clears.

AP3503EMPTR-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

AP3503EMPTR-G1 FAQ

1.How can I place an order for AP3503EMPTR-G1 through Aetrix?

Please submit a Request for Quotation (RFQ) for AP3503EMPTR-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 AP3503EMPTR-G1 reliable?

The price and inventory of AP3503EMPTR-G1 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for AP3503EMPTR-G1 is usually 5 days.

3.What payment methods are accepted for AP3503EMPTR-G1?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for AP3503EMPTR-G1 transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for AP3503EMPTR-G1?

AP3503EMPTR-G1 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your AP3503EMPTR-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 AP3503EMPTR-G1?

For technical support, including AP3503EMPTR-G1 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your AP3503EMPTR-G1 requirements.

6.How does Aetrix verify that AP3503EMPTR-G1 is sourced from the original manufacturer or authorized distributors?

All AP3503EMPTR-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 AP3503EMPTR-G1 meets industry standards.

7.What is the process for return or replacement of AP3503EMPTR-G1?

All AP3503EMPTR-G1 units undergo pre-shipment inspection (PSI). If there is an issue with AP3503EMPTR-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 AP3503EMPTR-G1 part is unused and in its original packaging.

Return procedure for AP3503EMPTR-G1:

1.Submit a request within 90 days.

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

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