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

Diodes Incorporated AP7343-185FS4-7B

Name: AP7343-185FS4-7B
Brand: Diodes Incorporated
SKU: AP7343-185FS4-7B
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: AP7343-185FS4-7B

Manufacturer:: Diodes Incorporated

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

Package:: 4-XDFN Exposed Pad

Datasheet:: AP7343-185FS4-7B.pdf

Description:: IC REG LINEAR 1.85V 300MA 4DFN

Quantity:: RFQ Add To RFQ list

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Product details

Overview

AP7343-185FS4-7B from Diodes Incorporated is a 300mA, 1.85V fixed-output low-dropout regulator with ±1% output voltage accuracy, 75dB PSRR at 1kHz, and 60µV_rms output noise (10Hz–100kHz), designed for RF supply rails in space-constrained portable electronics using the X2-DFN1010-4 (Type B) package.

For engineers reviewing the AP7343-185FS4-7B datasheet, AP7343-185FS4-7B pinout, AP7343-185FS4-7B application, or AP7343-185FS4-7B equivalent, key selection criteria include its 1.7V–5.25V input range, 35µA quiescent current, enable-controlled shutdown, thermal shutdown at +150°C, and compatibility with 1µF ceramic input/output capacitors.

Technical Context

The AP7343-185FS4-7B integrates a CMOS-based error amplifier, precision voltage reference, current-limit circuit, and thermal shutdown protection. Its architecture delivers fast load transient response (≤100µs recovery) and stable regulation under dynamic current steps from 1mA to 300mA with minimal output deviation.

It operates with an enable input (EN) that accepts logic-level control (0–0.5V low, 1.3–5.25V high), supports shutdown current of ≤1.0µA, and features a non-discharge output configuration-meaning VOUT remains floating during disable, avoiding unintended discharge paths in multi-rail systems.

Key Specifications

Parameter	Value and Actual Design Meaning
Output Voltage	Fixed 1.85V ±1% - ensures stable bias for RF power amplifiers and analog baseband ICs without external feedback resistors.
Max Output Current	300mA - sufficient to power dual-band RF transceivers or image sensor interfaces in smartphones and tablets.
PSRR	75dB at 1kHz - suppresses switching noise from adjacent DC/DC converters feeding noisy system rails.
Output Noise	60µV_rms (10Hz–100kHz) - meets stringent spectral purity requirements for RF front-end LNA and mixer biasing.
Quiescent Current	35µA typical - enables >10-year battery life in always-on sensor nodes or standby modes of portable media players.
Dropout Voltage	0.35V max at 300mA (VOUT = 1.85V) - allows operation from single-cell Li-ion (3.0V min) or 2-cell alkaline (2.4V min) sources.
Operating Temp	−40°C to +85°C ambient - qualified for industrial and consumer handheld environments without derating.

Pinout & Package

X2-DFN1010-4 (Type B) package: 1.0mm × 1.0mm, 0.4mm pitch, exposed thermal pad (EP) - optimized for high-density PCB layouts and thermal dissipation via GND-connected copper area.

Pin/Terminal	Circuit Role	Design Meaning
PIN1 (VOUT)	Regulated Power Output	Delivers clean 1.85V to load; requires local 1µF ceramic capacitor placed within 2mm of pin for stability and transient response.
PIN2 (GND)	Analog/Digital Ground Reference	Primary return path for regulator current; must connect directly to low-impedance ground plane, not shared with noisy digital returns.
PIN3 (EN)	Enable Control Input	Active-high logic interface; must be driven (not floated); 0.5V max low threshold ensures compatibility with 1.8V/3.3V GPIOs.
PIN4 (VIN)	Unregulated Input Supply	Accepts 1.7V–5.25V; requires 0.47µF ceramic decoupling capacitor placed adjacent to pin to suppress supply glitches.
EP (Exposed Pad)	Thermal Conductor / Optional GND Tie	Not electrically functional; soldered to ≥25mm² GND copper pour to reduce θ_JA from 237°C/W to <100°C/W in production layout.

Key Features

Feature	Design Value
High PSRR at RF frequencies	75dB @ 1kHz, >40dB up to 1MHz - preserves signal integrity in LTE/Wi-Fi front-end bias networks.
Ultra-low quiescent current	35µA typical - enables micro-power operation in always-on wake-up circuits without compromising startup time.
Fast load transient response	≤100µs recovery from 30mA ↔ 300mA step with 1µF C_OUT - maintains voltage margin during burst-mode RF transmission.
Robust thermal protection	+150°C shutdown with +20°C hysteresis - prevents latch-up during sustained overload or poor PCB thermal design.
Small-footprint packaging	X2-DFN1010-4 (1.0mm × 1.0mm) - saves >60% board area vs. SOT25, critical for camera modules and wearable sensors.

Applications

RF Power Amplifier Bias

CMOS Image Sensor Core Supply

Use Scenario: Providing clean, low-noise bias to GaAs pHEMT power amplifiers in 4G/5G mobile handsets.

IC Role / Device Role / Timing Role: Primary LDO delivering regulated 1.85V to PA drain supply, rejecting noise from PMIC switching rails.

Use Value: 60µV_rms noise and 75dB PSRR prevent AM-to-PM distortion and EVM degradation in transmit chain.

Use Scenario: Powering analog core and PLL circuits of high-resolution CMOS image sensors in smartphone cameras.

IC Role / Device Role / Timing Role: Low-noise, fast-response LDO supplying sensor analog block and timing generator.

Use Value: Sub-100µs transient recovery maintains pixel clock stability during auto-exposure gain changes.

Portable Media Player Audio Codec

Wireless Adapter Baseband IC

Use Scenario: Supplying DAC/ADC reference voltage and analog front-end in battery-powered MP3 players.

IC Role / Device Role / Timing Role: Precision LDO generating stable 1.85V reference rail for audio signal chain components.

Use Value: ±1% accuracy and low drift (±30ppm/°C) ensure consistent THD+N performance across temperature.

Use Scenario: Regulating supply for Bluetooth/Wi-Fi SoC baseband processors in USB dongles and IoT adapters.

IC Role / Device Role / Timing Role: Enable-controlled LDO powering SoC I/O and memory interface blocks during active/inactive states.

Use Value: 1.0µA shutdown current extends battery runtime in intermittent-connectivity applications.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
MCP1700-1802E/TO	250mA max output, 6µV_rms noise (10Hz–100kHz), no enable pin, TO-92 package	Lacks EN control and thermal shutdown; limited to low-current, non-critical analog rails	Select only when enable functionality and 300mA drive are unnecessary and through-hole assembly is required.
Torex XC6219B182MR-G	300mA, 1.8V output, 45dB PSRR @ 1kHz, 15µV_rms noise, SOT-25 package	Lower PSRR and noise than AP7343-185FS4-7B; lacks thermal hysteresis specification	Prefer for cost-sensitive designs where RF noise rejection is secondary to basic regulation.

Compared with MCP1700-1802E/TO and XC6219B182MR-G, the AP7343-185FS4-7B uniquely combines 300mA drive, 75dB PSRR, 60µV_rms noise, and enable control in a 1.0mm × 1.0mm DFN-making it optimal for RF and imaging subsystems demanding both density and spectral purity.

Availability

AP7343-185FS4-7B is available at Aetrix Electronics and suitable for RF power amplifier biasing, CMOS image sensor core supplies, and portable media player audio codec regulation requiring stable component supply, full traceability, and long-term lifecycle support.

Supply support for AP7343-185FS4-7B 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 solutions for power management, signal integrity, and connectivity applications.

The AP7343 series belongs to Diodes' high-PSRR, low-noise LDO product line, engineered specifically for noise-sensitive RF, imaging, and portable communication systems where compact size and precision regulation are critical.

FAQ

What is the minimum input voltage required for stable 1.85V output at 300mA?

The AP7343-185FS4-7B requires VIN ≥ 2.20V to maintain regulation at 300mA, based on its maximum dropout voltage of 0.35V at that load. Below this, output voltage sags linearly with input; operation below 1.7V is prohibited per absolute maximum ratings.

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

No-the EN pin must never be left floating. If enable control is unused, tie EN directly to VIN to ensure permanent activation. Floating EN causes unpredictable behavior due to internal leakage paths and may result in erratic output or increased quiescent current.

Is the X2-DFN1010-4 (Type B) package lead-free and RoHS compliant?

Yes-AP7343-185FS4-7B is fully RoHS 3 compliant (2015/863/EU), lead-free, halogen-free (<900ppm Br+Cl), and antimony-free, meeting Diodes Incorporated's "Green" device standard per datasheet notes 1–3.

Does this part include output discharge functionality?

No-AP7343-185FS4-7B is the non-discharge variant (no "D" suffix). When disabled, VOUT remains high-impedance and does not actively pull down. For automatic discharge, select AP7343D-185FS4-7B instead.

AP7343-185FS4-7B 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):: 1.85V

Voltage - Output (Max):: -

Voltage Dropout (Max):: 0.39V @ 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

AP7343-185FS4-7B FAQ

1.How can I place an order for AP7343-185FS4-7B through Aetrix?

Please submit a Request for Quotation (RFQ) for AP7343-185FS4-7B 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 AP7343-185FS4-7B reliable?

The price and inventory of AP7343-185FS4-7B are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for AP7343-185FS4-7B is usually 5 days.

3.What payment methods are accepted for AP7343-185FS4-7B?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for AP7343-185FS4-7B transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for AP7343-185FS4-7B?

AP7343-185FS4-7B orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your AP7343-185FS4-7B 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 AP7343-185FS4-7B?

For technical support, including AP7343-185FS4-7B datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your AP7343-185FS4-7B requirements.

6.How does Aetrix verify that AP7343-185FS4-7B is sourced from the original manufacturer or authorized distributors?

All AP7343-185FS4-7B 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 AP7343-185FS4-7B meets industry standards.

7.What is the process for return or replacement of AP7343-185FS4-7B?

All AP7343-185FS4-7B units undergo pre-shipment inspection (PSI). If there is an issue with AP7343-185FS4-7B, 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 AP7343-185FS4-7B part is unused and in its original packaging.

Return procedure for AP7343-185FS4-7B:

1.Submit a request within 90 days.

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

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