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Home > Products > Integrated Circuits (ICs) > Power Management (PMIC) > Voltage Regulators - Linear, Low Drop Out (LDO) Regulators

Diodes Incorporated AP7343-31FS4-7B

Name: AP7343-31FS4-7B
Brand: Diodes Incorporated
SKU: AP7343-31FS4-7B
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: AP7343-31FS4-7B

Manufacturer:: Diodes Incorporated

Category:: Voltage Regulators - Linear, Low Drop Out (LDO) Regulators

Package:: 4-XDFN Exposed Pad

Datasheet:: AP7343-31FS4-7B.pdf

Description:: IC REG LINEAR 3.1V 300MA 4DFN

Quantity:: RFQ Add To RFQ list

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Product details

Overview

AP7343-31FS4-7B from Diodes Incorporated is a 300mA, 3.1V fixed-output low-dropout regulator with ±1% output accuracy, 75dB PSRR at 1kHz, and 60µV_rms output noise (10Hz–100kHz). Built on CMOS process, it features enable control, thermal shutdown, and short-circuit protection, and is optimized for RF supply rails in compact portable electronics.

For engineers reviewing the AP7343-31FS4-7B datasheet, AP7343-31FS4-7B pinout, AP7343-31FS4-7B application, or AP7343-31FS4-7B equivalent, key selection criteria include its 0.22–0.29V dropout at 300mA (for 3.1V output), 35µA quiescent current, X2-DFN1010-4 (Type B) package footprint, and EN-controlled power sequencing capability.

Technical Context

The AP7343-31FS4-7B integrates a precision voltage reference, error amplifier, current-limit circuit, and CMOS pass transistor - enabling stable regulation across 1.7V–5.25V input while maintaining ±1% V_OUT accuracy over temperature (−40°C to +85°C) and load (0–300mA).

Its enable input (EN) provides clean on/off control with defined thresholds (V_IL ≤ 0.5V, V_IH ≥ 1.3V), and internal thermal shutdown activates at +150°C with +20°C hysteresis. The device lacks built-in output discharge (non-D variant), requiring external circuitry if fast V_OUT decay is needed.

Key Specifications

Parameter	Value and Actual Design Meaning
Output Voltage	Fixed 3.1V ±1% at TA = +25°C; maintains stability across −40°C to +85°C ambient.
Max Output Current	300mA continuous - supports moderate-power RF ICs and sensor subsystems without derating at 85°C.
Dropout Voltage	0.22V (typ) to 0.29V (max) at 300mA - enables operation from 3.32V input when powering 3.1V rail.
PSRR	75dB at 1kHz - suppresses switching noise from adjacent DC/DC converters feeding shared input rails.
Output Noise	60µV_rms (10Hz–100kHz) - meets low-noise requirements for RF front-end biasing and ADC reference supplies.
Quiescent Current	35µA (typ) - extends battery life in always-on monitoring circuits and standby modes.
Enable Thresholds	V_{EN_H} ≥ 1.3V, V_{EN_L} ≤ 0.5V - compatible with 1.8V/3.3V GPIO without level-shifting.

Pinout & Package

X2-DFN1010-4 (Type B) package: 1.0mm × 1.0mm, 0.4mm pitch, exposed thermal pad (EP) - requires PCB copper pour connected to GND for optimal thermal performance (R_θJA = 237°C/W).

Pin/Terminal	Circuit Role	Design Meaning
PIN1 (VOUT)	Regulated Power Output	Delivers stable 3.1V to load; must be decoupled with ≥1µF ceramic capacitor placed adjacent to pin.
PIN2 (GND)	Power Ground Reference	Primary return path for load current and internal circuitry; connects to EP for thermal conduction.
PIN3 (EN)	Enable Control Input	Active-high logic input; floating state is undefined - tie to VIN or MCU GPIO to ensure deterministic startup/shutdown.
PIN4 (VIN)	Unregulated Input Supply	Accepts 1.7V–5.25V; requires ≥0.47µF ceramic decoupling capacitor placed within 2mm of pin.
EP (Exposed Pad)	Thermal & Electrical Ground	Not electrically functional as standalone GND electrode; must be soldered and thermally coupled to large PCB copper area tied to system GND.

Key Features

Feature	Design Value
High PSRR (75dB @ 1kHz)	Enables clean power delivery to noise-sensitive RF blocks even when sharing noisy switcher inputs.
Ultra-low 60µV_rms noise	Supports high-resolution analog signal chains (e.g., audio codecs, precision sensors) without additional filtering.
35µA quiescent current	Reduces standby power loss in battery-powered IoT nodes where sleep current directly impacts service life.
±1% output accuracy	Eliminates need for external trimming in applications requiring tight voltage tolerance (e.g., memory I/O, core logic rails).
Thermal shutdown + hysteresis	Prevents latch-up during sustained overload; +20°C hysteresis ensures reliable recovery after fault clearance.

Applications

RF Power Amplifier Bias

Camera Sensor Core Supply

Use Scenario: Providing stable 3.1V bias to GaAs pHEMT power amplifiers in 4G/5G mobile front-ends.

IC Role / Device Role / Timing Role: Low-noise LDO delivering regulated V_PA rail with minimal AM-to-PM distortion under dynamic load.

Use Value: 75dB PSRR rejects PA collector switching noise; 60µV_rms noise prevents EVM degradation in QAM64/256 modulation schemes.

Use Scenario: Powering image sensor analog core (ADC reference, pixel array bias) in smartphone camera modules.

IC Role / Device Role / Timing Role: Precision voltage source ensuring consistent pixel response and low fixed-pattern noise across temperature.

Use Value: ±1% accuracy maintains sensor gain linearity; 35µA IQ enables always-on low-power preview mode without battery drain.

Wireless Adapter SoC I/O Rail

Portable Media Player Audio Codec

Use Scenario: Supplying 3.1V I/O voltage to Wi-Fi/BT combo chips in USB dongles and embedded wireless peripherals.

IC Role / Device Role / Timing Role: Regulator interfacing between host 3.3V rail and SoC I/O pins requiring tighter voltage tolerance.

Use Value: 0.22V dropout allows operation from marginally regulated 3.3V sources; EN pin enables synchronized power-up with host enumeration.

Use Scenario: Generating clean 3.1V supply for stereo audio DAC/ADC in flash-based MP3 players.

IC Role / Device Role / Timing Role: Low-noise analog rail isolating sensitive audio circuitry from digital switching noise.

Use Value: 60µV_rms noise avoids audible hiss; 300mA output supports headphone driver stages without sag during bass transients.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
MCP1700-3102E/TO	300mA, 3.1V, ±2% accuracy, 65dB PSRR @ 1kHz, 3.5µA IQ, TO-92 package.	Larger footprint, lower PSRR, higher noise (80µV_rms); suited for cost-sensitive non-RF applications.	Select when board space is unconstrained and ultra-low noise is not required; avoid in RF or high-speed data paths.
Torex XC6210B312MR-G	300mA, 3.1V, ±1% accuracy, 70dB PSRR @ 1kHz, 45µA IQ, SOT-25 package.	SOT-25 footprint (larger than X2-DFN1010-4); slightly higher IQ and lower PSRR than AP7343-31FS4-7B.	Choose when legacy SOT-25 layout compatibility is mandatory; verify thermal performance with R_θJA = 179°C/W.

Compared with MCP1700-3102E/TO and XC6210B312MR-G, the AP7343-31FS4-7B delivers superior noise/PSRR performance in the smallest footprint, making it optimal for space-constrained RF and imaging systems where signal integrity is critical.

Availability

AP7343-31FS4-7B is available at Aetrix Electronics and suitable for RF power amplifier biasing, camera sensor core supplies, wireless adapter SoC I/O rails, and portable media player audio codecs requiring stable component supply, long-term manufacturability, and RoHS-compliant packaging.

Supply support for AP7343-31FS4-7B 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 semiconductor company specializing in discrete, analog, and mixed-signal devices, with design and manufacturing operations across Asia, Europe, and the Americas.

The AP7343 series belongs to Diodes' high-performance LDO portfolio, engineered specifically for low-noise, high-PSRR power delivery in battery-powered portable electronics and RF subsystems.

FAQ

What is the minimum input voltage required for stable 3.1V output at 300mA?

The AP7343-31FS4-7B requires VIN ≥ 3.32V (3.1V + 0.22V typical dropout) for full 300mA output at room temperature. At 85°C, worst-case dropout rises to 0.29V, so VIN ≥ 3.39V is recommended for guaranteed performance across temperature.

Can the EN pin be left unconnected if enable functionality is not used?

No - the EN pin must never be left floating. To maintain permanent enable, connect EN directly to VIN. Floating EN causes undefined behavior and potential oscillation due to noise coupling into the high-impedance input.

Does AP7343-31FS4-7B include output discharge functionality?

No - the "7B" suffix indicates the standard (non-discharge) version. Output discharge is only available in AP7343D variants (e.g., AP7343D-31FS4-7B), which integrate an internal NMOS switch to actively pull VOUT to GND when disabled.

What is the recommended PCB layout practice for the exposed pad (EP)?

The EP must be soldered and connected to a large GND copper pour on the PCB - not used as a standalone GND electrode. Thermal vias (≥4×0.3mm) should connect the EP to inner-layer ground planes to achieve R_θJB ≈ 85.7°C/W and prevent junction overheating at full load.

AP7343-31FS4-7B Specifications

Product attributes: Attribute value

Manufacturer:: Diodes Incorporated

Series:: -

Package/Case:: 4-XDFN Exposed Pad

Packaging:: Tape & Reel (TR)

Product Status:: Active

Output Configuration:: Positive

Output Type:: Fixed

Number of Regulators:: 1

Voltage - Input (Max):: 5.25V

Voltage - Output (Min/Fixed):: 3.1V

Voltage - Output (Max):: -

Voltage Dropout (Max):: 0.29V @ 300mA

Current - Output:: 300mA

Current - Quiescent (Iq):: 60 µA

Current - Supply (Max):: -

PSRR:: 75dB (1kHz)

Control Features:: Enable

Protection Features:: Over Current

Operating Temperature:: -40°C ~ 85°C

Grade:: -

Qualification:: -

Mounting Type:: Surface Mount

Supplier Device Package:: X2-DFN1010-4

AP7343-31FS4-7B FAQ

1.How can I place an order for AP7343-31FS4-7B through Aetrix?

Please submit a Request for Quotation (RFQ) for AP7343-31FS4-7B 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 AP7343-31FS4-7B reliable?

The price and inventory of AP7343-31FS4-7B are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for AP7343-31FS4-7B is usually 5 days.

3.What payment methods are accepted for AP7343-31FS4-7B?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for AP7343-31FS4-7B transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for AP7343-31FS4-7B?

AP7343-31FS4-7B orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your AP7343-31FS4-7B 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 AP7343-31FS4-7B?

For technical support, including AP7343-31FS4-7B datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your AP7343-31FS4-7B requirements.

6.How does Aetrix verify that AP7343-31FS4-7B is sourced from the original manufacturer or authorized distributors?

All AP7343-31FS4-7B 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 AP7343-31FS4-7B meets industry standards.

7.What is the process for return or replacement of AP7343-31FS4-7B?

All AP7343-31FS4-7B units undergo pre-shipment inspection (PSI). If there is an issue with AP7343-31FS4-7B, 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 AP7343-31FS4-7B part is unused and in its original packaging.

Return procedure for AP7343-31FS4-7B:

1.Submit a request within 90 days.

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

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