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

Diodes Incorporated AP7343D-135FS4-7B

Name: AP7343D-135FS4-7B
Brand: Diodes Incorporated
SKU: AP7343D-135FS4-7B
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: AP7343D-135FS4-7B

Manufacturer:: Diodes Incorporated

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

Package:: 4-XDFN Exposed Pad

Datasheet:: AP7343D-135FS4-7B.pdf

Description:: IC REG LINEAR 1.35V 300MA 4DFN

Quantity:: RFQ Add To RFQ list

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Product details

Overview

AP7343D-135FS4-7B from Diodes Incorporated is a 300mA, 1.35V fixed-output low-dropout linear regulator with high PSRR (75dB at 1kHz), ultra-low output noise (60µV_rms, 10Hz–100kHz), and ±1% output voltage accuracy over temperature. Fabricated on a CMOS process, it features enable control, thermal shutdown, short-circuit protection, and integrated auto-discharge functionality-optimized for powering RF sections and precision analog rails in space-constrained portable electronics.

For engineers reviewing the AP7343D-135FS4-7B datasheet, AP7343D-135FS4-7B pinout, AP7343D-135FS4-7B application, or AP7343D-135FS4-7B equivalent, key selection criteria include dropout voltage at 300mA (0.39V max for 1.35V output), quiescent current (35µA typ), EN input thresholds (0.5V low / 1.3V high), and X2-DFN1010-4 (Type B) thermal performance (R_θJA = 237°C/W).

Technical Context

The AP7343D integrates a precision voltage reference, error amplifier, current-limit circuit, and NMOS pass transistor with built-in discharge path-enabling fast turn-off and elimination of residual output voltage during shutdown. Its CMOS architecture delivers stable regulation across 1.7V–5.25V input while maintaining low quiescent current even under light loads.

Designed for high-transient environments, it achieves <30mV load regulation (1mA–300mA) and exhibits robust line regulation (0.02%/V typ). The device includes thermal shutdown at +150°C with +20°C hysteresis and ESD protection (>2kV HBM), supporting reliable operation in handheld and battery-powered systems.

Key Specifications

Parameter	Value and Actual Design Meaning
Output Voltage	Fixed 1.35V ±1% at +25°C; ±30ppm/°C tempco ensures stability across –40°C to +85°C ambient.
Max Output Current	300mA guaranteed continuous output; fold-back short-circuit current ~55mA protects against sustained overloads.
Dropout Voltage	0.39V max at 300mA (1.35V output), enabling operation with VIN as low as 1.74V-critical for single-cell Li-ion or Li-poly systems.
PSRR	75dB at 1kHz, >60dB up to 100kHz-suppresses switching noise from adjacent DC/DC converters feeding sensitive RF or ADC circuits.
Output Noise	60µV_rms (10Hz–100kHz), enabling clean biasing for low-noise amplifiers, PLLs, and high-resolution data converters.
Quiescent Current	35µA typical (60µA max); ISTANDBY <1.0µA when disabled-extends battery life in always-on sensor or standby subsystems.
Enable Thresholds	V_EN(HI) ≥1.3V, V_EN(LO) ≤0.5V; supports direct interfacing with 1.8V/3.3V GPIO without level-shifting.

Pinout & Package

AP7343D-135FS4-7B is housed in the X2-DFN1010-4 (Type B) package-a 1.0mm × 1.0mm, 0.4mm pitch, 4-terminal leadless package with exposed thermal pad (EP). The EP must be connected to GND via large copper area for optimal thermal dissipation (R_θJB = 85.7°C/W).

Pin/Terminal	Circuit Role	Design Meaning
PIN1 (VOUT)	Regulated Power Output	Delivers 1.35V ±1% to load; requires 1µF ceramic capacitor placed adjacent to minimize impedance and ensure transient stability.
PIN2 (GND)	Analog & Power Ground Reference	Primary return path for output current and internal circuitry; must connect directly to low-impedance ground plane to avoid noise coupling.
PIN3 (EN)	Active-High Enable Control	Drives regulator ON/OFF; must not float-tie to VIN if unused; compatible with 1.8V logic levels.
PIN4 (VIN)	Input Power Supply	Accepts 1.7V–5.25V; requires 0.47µF ceramic decoupling capacitor placed within 2mm of pin to suppress supply transients.
EP (Exposed Pad)	Thermal Dissipation Path	Not electrically functional; soldered to PCB GND pour to reduce junction-to-board thermal resistance by >50% vs. no-pad layout.

Key Features

Feature	Design Value
Auto-Discharge Function	Integrated NMOS discharge path (R_ON ≈30Ω) actively pulls VOUT to GND within microseconds after EN deactivation-prevents floating outputs in multi-rail sequencing.
High PSRR at Low Frequencies	75dB rejection at 1kHz enables use downstream of noisy buck converters without additional filtering-reducing BOM count and board area.
Ultra-Low Noise Output	60µV_rms broadband noise meets stringent requirements for RF transceivers, audio codecs, and precision ADC references.
Low Dropout at Full Load	0.39V dropout at 300mA allows operation from 1.74V input-supporting single-cell battery applications down to end-of-life voltage.
Thermal Protection	+150°C shutdown with +20°C hysteresis prevents latch-up during sustained overload or poor heatsinking-ensures safe recovery without external intervention.

Applications

RF Power Amplifier Biasing

Mobile Camera Sensor Core Supply

Use Scenario: Providing clean, stable 1.35V bias to GaAs pHEMT power amplifiers in 4G/5G front-end modules where supply ripple directly impacts EVM and ACLR.

IC Role / Device Role / Timing Role: Low-noise LDO delivering regulated core voltage with minimal PSK/ASK modulation sidebands induced by supply noise.

Use Value: 60µV_rms noise and 75dB PSRR suppress switching artifacts from PMIC DC/DC stages, improving transmit spectral purity by >3dB.

Use Scenario: Powering CIS (CMOS Image Sensor) analog core and PLL circuits in smartphone rear cameras requiring sub-2mV ripple under dynamic exposure control.

IC Role / Device Role / Timing Role: Precision voltage source maintaining 1.35V ±13.5mV across –40°C to +85°C for pixel readout consistency and clock jitter reduction.

Use Value: ±1% initial accuracy and ±30ppm/°C tempco limit voltage drift to <±0.5% over full temperature range-preserving image SNR and color fidelity.

Wireless Adapter Baseband IC Supply

Portable Media Player Audio DAC Reference

Use Scenario: Supplying baseband processor I/O and memory interfaces in USB-C wireless dongles where EMI from host USB traffic must not corrupt digital signaling.

IC Role / Device Role / Timing Role: Isolation barrier between noisy USB VBUS domain and sensitive digital logic-rejecting 1–100MHz common-mode noise via high PSRR.

Use Value: 75dB PSRR at 1kHz and >60dB up to 100kHz attenuates USB packet-induced supply perturbations, reducing bit error rate by 10× vs. standard LDOs.

Use Scenario: Generating ultra-quiet 1.35V reference for stereo DACs in Bluetooth headphones, where supply noise manifests as audible hiss or distortion.

IC Role / Device Role / Timing Role: Low-noise analog rail isolating DAC core from shared system power, minimizing THD+N degradation in audio signal chain.

Use Value: 60µV_rms noise floor ensures DAC SNR remains >110dB-meeting Hi-Res Audio certification requirements without external filtering.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
MCP1700T-1302E/TT	1.3V fixed output, 250mA max, 6µA IQ, no enable or discharge; SOT23-5 package.	Lacks EN control and auto-discharge; unsuitable for power sequencing or fast shutdown.	Select only for ultra-low-IQ, non-sequenced, low-current (<250mA) applications where footprint permits SOT23-5.
Torex XC6210B132MR-G	1.3V fixed output, 300mA, 25µA IQ, no discharge; USP-4 package (1.2×1.2mm).	No discharge function; slightly smaller package but higher R_θJA (300°C/W) limits thermal headroom at full load.	Prefer for space-constrained designs needing lowest IQ, but verify thermal margin with 300mA continuous load.

Compared with MCP1700T-1302E/TT and XC6210B132MR-G, AP7343D-135FS4-7B uniquely combines 1.35V precision, 300mA capability, active discharge, and 75dB PSRR in a 1.0mm² footprint-making it the only choice for RF-biased, sequenced, and noise-sensitive dual-rail mobile subsystems.

Availability

AP7343D-135FS4-7B is available at Aetrix Electronics and suitable for RF power amplifier biasing, mobile camera sensor core supplies, wireless adapter baseband ICs, and portable media player audio DAC references requiring stable component supply, consistent parametric performance, and long-term production continuity.

Supply support for AP7343D-135FS4-7B 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 manufacturer specializing in discrete, analog, and mixed-signal solutions for consumer, computing, communications, industrial, and automotive markets.

The AP7343 series belongs to Diodes' high-performance LDO portfolio, engineered specifically for battery-powered portable electronics demanding ultra-low noise, high PSRR, and compact packaging-addressing critical power integrity challenges in multi-rail mobile SoC architectures.

FAQ

What is the maximum input voltage for AP7343D-135FS4-7B?

The absolute maximum input voltage is 6.0V, but the recommended operating range is 1.7V to 5.25V. Exceeding 5.25V may trigger internal protection or degrade long-term reliability. For 1.35V output, minimum functional VIN is 1.74V (1.35V + 0.39V dropout), making it ideal for single-cell Li-ion (2.5V–4.2V) and Li-poly systems.

Does AP7343D-135FS4-7B require an external discharge resistor?

No. The "D" suffix denotes integrated auto-discharge functionality: an internal 30Ω NMOS switch connects VOUT to GND when EN is low, eliminating need for external components. This reduces BOM count and ensures rapid, controlled VOUT decay-critical for power sequencing compliance in multi-voltage systems.

Can AP7343D-135FS4-7B be used with ceramic output capacitors smaller than 1µF?

Yes-stability is guaranteed with ≥0.47µF ceramic capacitors (X5R/X7R, 6.3V rating). However, 1µF is recommended for optimal transient response under 300mA load steps. Lower values increase output voltage deviation during fast load changes; ESR must remain <10mΩ to stay within stable region per datasheet ESR vs. IOUT graph.

How does thermal performance differ between X2-DFN1010-4 and SOT25 packages?

X2-DFN1010-4 (Type B) has R_θJA = 237°C/W and R_θJB = 85.7°C/W; SOT25 has R_θJA = 179°C/W and R_θJB = 79.2°C/W. Though SOT25 offers better ambient thermal resistance, its larger footprint (2.9mm × 1.6mm) consumes 4.5× more board area. X2-DFN1010-4's superior board-level thermal coupling makes it preferred for dense, thermally constrained layouts despite higher R_θJA.

AP7343D-135FS4-7B 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):: 1.35V

Voltage - Output (Max):: -

Voltage Dropout (Max):: 0.58V @ 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

AP7343D-135FS4-7B FAQ

1.How can I place an order for AP7343D-135FS4-7B through Aetrix?

Please submit a Request for Quotation (RFQ) for AP7343D-135FS4-7B 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 AP7343D-135FS4-7B reliable?

The price and inventory of AP7343D-135FS4-7B are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for AP7343D-135FS4-7B is usually 5 days.

3.What payment methods are accepted for AP7343D-135FS4-7B?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for AP7343D-135FS4-7B transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for AP7343D-135FS4-7B?

AP7343D-135FS4-7B orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your AP7343D-135FS4-7B 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 AP7343D-135FS4-7B?

For technical support, including AP7343D-135FS4-7B datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your AP7343D-135FS4-7B requirements.

6.How does Aetrix verify that AP7343D-135FS4-7B is sourced from the original manufacturer or authorized distributors?

All AP7343D-135FS4-7B 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 AP7343D-135FS4-7B meets industry standards.

7.What is the process for return or replacement of AP7343D-135FS4-7B?

All AP7343D-135FS4-7B units undergo pre-shipment inspection (PSI). If there is an issue with AP7343D-135FS4-7B, 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 AP7343D-135FS4-7B part is unused and in its original packaging.

Return procedure for AP7343D-135FS4-7B:

1.Submit a request within 90 days.

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

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