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

Diodes Incorporated AP7343-09FS4-7B

Name: AP7343-09FS4-7B
Brand: Diodes Incorporated
SKU: AP7343-09FS4-7B
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: AP7343-09FS4-7B

Manufacturer:: Diodes Incorporated

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

Package:: 4-XDFN Exposed Pad

Datasheet:: AP7343-09FS4-7B.pdf

Description:: IC REG LINEAR 0.9V 300MA 4DFN

Quantity:: RFQ Add To RFQ list

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Product details

Overview

AP7343-09FS4-7B from Diodes Incorporated is a 300mA, 0.9V fixed-output low-dropout linear regulator with ±1% output voltage accuracy, 75dB PSRR at 1kHz, and 60µV_rms output noise (10Hz–100kHz). Built on a CMOS process, it features enable control, thermal shutdown, and short-circuit protection-designed for powering RF circuitry and core logic rails in space-constrained portable devices.

For engineers reviewing the AP7343-09FS4-7B datasheet, AP7343-09FS4-7B pinout, AP7343-09FS4-7B application, or AP7343-09FS4-7B equivalent, key selection criteria include its 0.9V fixed output, 1.7V–5.25V input range, 35µA quiescent current, X2-DFN1010-4 (Type B) package, and high PSRR performance under light-to-moderate load transients.

Technical Context

The AP7343-09FS4-7B integrates a precision voltage reference, error amplifier, current-limit circuit, and NMOS pass transistor in a CMOS-based architecture. Its enable input (EN) provides precise on/off control with defined logic thresholds (V_IL ≤ 0.5V, V_IH ≥ 1.3V), and internal thermal shutdown activates at +150°C with +20°C hysteresis.

It delivers stable 0.9V output across –40°C to +85°C ambient, with dropout voltage as low as 0.51V at 300mA (X2-DFN1010-4 package). The device exhibits low output impedance and fast load transient response-critical for powering noise-sensitive RF ICs and low-voltage microcontroller cores.

Key Specifications

Parameter	Value and Actual Design Meaning
Output Voltage	Fixed 0.9V ±1% at +25°C; supports core logic and I/O rails requiring tight regulation.
Max Output Current	300mA continuous; sufficient for baseband processors, PMIC sub-rails, and sensor interfaces.
Input Voltage Range	1.7V to 5.25V; compatible with single-cell Li-ion, Li-poly, and multi-cell alkaline/battery-backed systems.
PSRR	75dB at 1kHz; suppresses switching noise from DC/DC converters feeding adjacent power domains.
Output Noise	60µV_rms (10Hz–100kHz); enables clean supply for RF transceivers and ADC reference circuits.
Quiescent Current	35µA typical; extends battery life in always-on sensor nodes and standby modes.
Dropout Voltage	0.51V at 300mA (0.9V output); maintains regulation down to 1.41V input-ideal for aging battery operation.

Pinout & Package

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

Pin/Terminal	Circuit Role	Design Meaning
PIN1 (VOUT)	Regulated power output	Delivers stable 0.9V to load; must be decoupled with ≥1µF ceramic capacitor placed adjacent to pin.
PIN2 (GND)	Analog and power ground reference	Primary return path for output current and internal bias; connects to EP for thermal conduction.
PIN3 (EN)	Enable control input	Active-high logic interface; drives regulator ON when ≥1.3V, OFF when ≤0.5V-no pull-up required if tied to VIN.
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 and mechanical anchor	Not electrically functional as GND; must be soldered to large PCB copper pour for thermal relief (R_θJB = 85.7°C/W).

Key Features

Feature	Design Value
High PSRR	75dB at 1kHz ensures minimal coupling of DC/DC ripple into sensitive analog/RF blocks.
Ultra-low noise	60µV_rms (10Hz–100kHz) meets stringent requirements for RF front-end and precision ADC supplies.
Low quiescent current	35µA enables >1-year battery life in IoT sensors operating at 10µA average system current.
Thermal protection	+150°C shutdown with +20°C hysteresis prevents latch-up during sustained overload or poor PCB heatsinking.
Small footprint	X2-DFN1010-4 (1.0mm × 1.0mm) reduces PCB area by 70% vs. SOT25-critical for ultra-thin mobile designs.

Applications

Smartphone Baseband Core Supply

Wi-Fi/Bluetooth RF Transceiver Bias

Use Scenario: Powers ARM Cortex-A/M series application processor core rail in smartphone SoC subsystems.

IC Role / Device Role / Timing Role: Primary LDO delivering 0.9V at up to 300mA with <±1% accuracy and fast load transient recovery.

Use Value: Maintains CPU stability during burst-mode execution while rejecting noise from shared PMIC switchers.

Use Scenario: Supplies clean 0.9V bias to Wi-Fi 6/6E and Bluetooth 5.3 RF transceivers in mobile hotspots.

IC Role / Device Role / Timing Role: Low-noise post-regulator for PA driver stages and mixer LO paths.

Use Value: 60µV_rms noise and 75dB PSRR prevent EVM degradation and adjacent-channel leakage in 2.4/5GHz bands.

Wearable Sensor Hub Power

Industrial Wireless Node MCU Core

Use Scenario: Provides regulated 0.9V to ultra-low-power sensor fusion MCU (e.g., Nordic nRF52/nRF53) in hearables.

IC Role / Device Role / Timing Role: Always-on LDO with 35µA IQ supporting wake-on-motion and BLE advertising cycles.

Use Value: Enables 2-week battery life on CR2032 via minimal quiescent draw and efficient dropout at end-of-life voltage.

Use Scenario: Powers Cortex-M4/M33 core in LoRaWAN or NB-IoT edge node gateways deployed in remote locations.

IC Role / Device Role / Timing Role: Robust 0.9V supply with –40°C to +85°C operation and thermal shutdown for unattended field use.

Use Value: Ensures deterministic reset behavior and avoids brown-out resets during temperature cycling or battery sag.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
AP7343-09W5-7	SOT25 package (3.0mm × 1.7mm); higher R_θJA (179°C/W); same electrical specs.	Less suitable for ultra-dense layouts; better for hand-soldering or legacy board compatibility.	Select when thermal margin allows larger footprint or when SOT25 is preferred for assembly logistics.
Torex XC6210B092MR-G	0.9V fixed, 200mA max, 45µA IQ, 65dB PSRR @ 1kHz, SOT25 package.	Limited current headroom for burst-mode loads; lower PSRR impacts RF supply cleanliness.	Choose only for cost-sensitive, low-current applications where 300mA and 75dB PSRR are not required.

Compared with AP7343-09W5-7, the FS4 variant offers 30% smaller footprint and superior thermal resistance to board; versus XC6210B092MR-G, it delivers 50% higher output current and 10dB better PSRR-critical for next-gen wireless SoCs.

Availability

AP7343-09FS4-7B is available at Aetrix Electronics and suitable for smartphone baseband supplies, Wi-Fi/Bluetooth RF biasing, wearable sensor hub power, and industrial wireless node MCU core rails requiring stable component supply across automotive-grade temperature ranges and long production lifecycles.

Supply support for AP7343-09FS4-7B 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 manufacturer of discrete semiconductors and analog ICs, specializing in high-performance power management, signal integrity, and connectivity solutions for consumer, industrial, and automotive markets.

The AP7343 belongs to Diodes' high-PSRR, low-noise LDO family-engineered specifically for noise-sensitive RF and digital core applications in battery-powered portable electronics.

FAQ

What is the minimum input voltage required for stable 0.9V output at 300mA?

The AP7343-09FS4-7B requires VIN ≥ 1.41V to maintain regulation at 300mA (0.51V dropout + 0.9V output). Below this, output voltage sags nonlinearly; operation below 1.7V is outside recommended conditions per datasheet Section 5.

Can the EN pin be left floating during operation?

No-EN must be actively driven high (≥1.3V) or low (≤0.5V). Floating EN causes undefined output state and potential oscillation due to internal comparator sensitivity; tie to VIN if enable functionality is unused.

Is an external discharge FET needed for fast VOUT decay during shutdown?

No-the AP7343-09FS4-7B is the non-discharge variant (per ordering code "7B"). Output discharges only through load; for active discharge, select AP7343D-09FS4-7B, which integrates a 30Ω NMOS between VOUT and GND when disabled.

What is the maximum allowable PCB trace length between CIN and VIN/GND pins?

Input capacitor CIN (≥0.47µF ceramic) must be placed within 2mm of VIN and GND pins. Longer traces increase inductance, degrading high-frequency PSRR and risking instability during fast load transients per Application Note Section 12.

AP7343-09FS4-7B 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):: 0.9V

Voltage - Output (Max):: -

Voltage Dropout (Max):: 0.8V @ 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

AP7343-09FS4-7B FAQ

1.How can I place an order for AP7343-09FS4-7B through Aetrix?

Please submit a Request for Quotation (RFQ) for AP7343-09FS4-7B 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 AP7343-09FS4-7B reliable?

The price and inventory of AP7343-09FS4-7B are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for AP7343-09FS4-7B is usually 5 days.

3.What payment methods are accepted for AP7343-09FS4-7B?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for AP7343-09FS4-7B transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for AP7343-09FS4-7B?

AP7343-09FS4-7B orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your AP7343-09FS4-7B 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 AP7343-09FS4-7B?

For technical support, including AP7343-09FS4-7B datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your AP7343-09FS4-7B requirements.

6.How does Aetrix verify that AP7343-09FS4-7B is sourced from the original manufacturer or authorized distributors?

All AP7343-09FS4-7B 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 AP7343-09FS4-7B meets industry standards.

7.What is the process for return or replacement of AP7343-09FS4-7B?

All AP7343-09FS4-7B units undergo pre-shipment inspection (PSI). If there is an issue with AP7343-09FS4-7B, 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 AP7343-09FS4-7B part is unused and in its original packaging.

Return procedure for AP7343-09FS4-7B:

1.Submit a request within 90 days.

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

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