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

Diodes Incorporated AP7353D-45FS4-7

Name: AP7353D-45FS4-7
Brand: Diodes Incorporated
SKU: AP7353D-45FS4-7
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: AP7353D-45FS4-7

Manufacturer:: Diodes Incorporated

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

Package:: 4-XDFN Exposed Pad

Datasheet:: AP7353D-45FS4-7.pdf

Description:: LDO CMOS LOWCURR X2-DFN1010-4 (T

Quantity:: RFQ Add To RFQ list

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Product details

Overview

AP7353D-45FS4-7 from Diodes Incorporated is a 250mA low-dropout linear regulator with fixed 4.5V output, ±1% accuracy, 90dB PSRR at 1kHz, 10µV_rms output noise (10Hz–100kHz), and 18µA typical quiescent current. It features enable control, thermal shutdown, short-circuit protection, and integrated auto-discharge functionality - designed for RF supply rails and noise-sensitive analog circuits in portable electronics.

For engineers reviewing the AP7353D-45FS4-7 datasheet, AP7353D-45FS4-7 pinout, AP7353D-45FS4-7 application, or AP7353D-45FS4-7 equivalent, key selection considerations include dropout voltage at 250mA (114mV typ. for 4.5V output), EN logic thresholds (0.4V_IL/1.2V_IH), thermal resistance (237°C/W for X2-DFN1010-4), and discharge path resistance (35Ω).

Technical Context

The AP7353D-45FS4-7 implements a CMOS-based LDO architecture with internal voltage reference, error amplifier, current-limit circuit, and NMOS pass transistor. Its auto-discharge function activates upon EN deactivation, using a 35Ω internal N-channel switch to rapidly discharge the output capacitor - critical for power sequencing in multi-rail systems.

It operates across 2.0V–5.5V input range with guaranteed 250mA output, supports ceramic capacitors ≥0.7µF (1µF recommended), and maintains stability without ESR requirements. Fast load transient response (<20µs recovery for 1mA→250mA step) and 180µs turn-on time support dynamic power management in handheld devices.

Key Specifications

Parameter	Value and Actual Design Meaning
Output Voltage	Fixed 4.5V ±1% - eliminates external feedback resistors and ensures precision rail generation for 4.5V analog/RF subsystems.
Max Output Current	250mA - sufficient for powering baseband processors, RF transceivers, or camera ISPs in compact portable designs.
PSRR	90dB @ 1kHz, 70dB @ 10kHz - suppresses switching noise from adjacent DC-DC converters feeding noisy power domains.
Output Noise	10µV_rms (10Hz–100kHz) - enables clean biasing of VCOs, ADC references, and low-noise amplifiers without additional filtering.
Quiescent Current	18µA typical - extends battery life in always-on sensor nodes and standby modes of wearables and IoT endpoints.
Dropout Voltage	114mV typ. @ 250mA, 4.5V V_OUT - allows operation from single-cell Li-ion (3.0V min) while maintaining regulation down to 4.386V output.
Enable Thresholds	V_IL ≤ 0.4V, V_IH ≥ 1.2V - compatible with 1.8V/3.3V GPIOs and supports direct connection to microcontroller wake-up signals.

Pinout & Package

AP7353D-45FS4-7 uses the X2-DFN1010-4 (Type B) package: 1.0mm × 1.0mm, 0.65mm pitch, exposed thermal pad (EP), RoHS-compliant NiPdAu finish. The ultra-compact footprint enables high-density PCB layouts in space-constrained mobile applications.

Pin/Terminal	Circuit Role	Design Meaning
1: IN	Power Input	Accepts 2.0V–5.5V input; requires 1µF ceramic decoupling capacitor placed adjacent to minimize impedance and supply noise coupling.
2: GND	Ground Reference	Primary ground return path; must be connected to low-impedance PCB ground plane to ensure stability and thermal performance.
3: EN	Enable Control	Active-high digital input; floating state is undefined - must be tied high (to IN or system rail) or driven by GPIO to prevent unintended shutdown.
4: OUT	Regulated Output	Delivers stable 4.5V; requires 1µF ceramic output capacitor near pin to maintain loop stability and improve transient response.
EP	Exposed Thermal Pad	Not electrically functional as GND; soldered to large copper pour for thermal dissipation - improves θ_JA from 237°C/W to ~120°C/W in optimized layouts.

Key Features

Feature	Design Value
Auto-Discharge Function	35Ω internal NMOS switch discharges output capacitor when disabled - prevents residual voltage hold-up and enables safe power sequencing in multi-voltage systems.
Low-Noise Regulation	10µV_rms noise floor enables direct powering of RF synthesizers and precision analog front-ends without post-LDO filtering.
High PSRR at High Frequency	70dB rejection at 10kHz supports co-location with high-frequency switching regulators (e.g., 2MHz buck converters) without cross-talk.
Ultra-Low Quiescent Current	18µA typical I_Q reduces no-load power loss to <100µW at 5.5V input - critical for battery runtime in always-on edge sensors.
Robust Protection Suite	Thermal shutdown + short-circuit current limiting (~350mA) + overvoltage-safe EN pin (6V tolerant) - ensures reliability under fault conditions.

Applications

RF Power Amplifier Bias

Camera Image Signal Processor (ISP)

Use Scenario: Providing clean, stable 4.5V bias to GaAs pHEMT power amplifiers in 5G NR sub-6GHz front-end modules.

IC Role / Device Role / Timing Role: Low-noise LDO delivering regulated V_PA rail with minimal phase noise contribution to transmit chain.

Use Value: 90dB PSRR suppresses DC-DC ripple from system PMIC, preventing AM-to-PM distortion and maintaining ACLR compliance.

Use Scenario: Supplying core voltage to image signal processors in smartphone dual-camera modules requiring fast wake/sleep transitions.

IC Role / Device Role / Timing Role: Enable-controlled LDO enabling rapid power gating of ISP logic blocks during frame capture intervals.

Use Value: 180µs turn-on time and 35Ω discharge path allow sub-millisecond rail ramp-up/ramp-down, reducing idle power by >40% vs. non-discharge alternatives.

Portable Media Player Audio Codec

Wearable Heart Rate Monitor Analog Front-End

Use Scenario: Powering stereo audio DACs and headphone amplifiers in Bluetooth-enabled media players where battery life and SNR are critical.

IC Role / Device Role / Timing Role: Ultra-low-noise LDO generating clean 4.5V AVDD for audio signal path components.

Use Value: 10µV_rms output noise contributes <−120dBV residual noise floor, preserving >110dB SNR in 24-bit audio playback.

Use Scenario: Supplying analog sensor interface circuitry (LED drivers, photodiode amps, ADC reference) in optical PPG heart rate sensors.

IC Role / Device Role / Timing Role: Precision LDO ensuring stable 4.5V rail despite varying battery voltage (3.0–4.2V) during discharge cycle.

Use Value: ±1% output accuracy and 0.004%/mA load regulation maintain consistent LED current and ADC reference scaling across battery life.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
AP7361D-45FS4-7	Higher 600mA output current, same 4.5V fixed output, identical X2-DFN1010-4 package and EN/discharge functionality.	Better suited for systems with peak current demands >250mA (e.g., multi-sensor fusion hubs), but higher quiescent current (25µA typ.) reduces battery efficiency.	Select when future-proofing for higher load margins or concurrent peripheral activation; avoid if strict µA-level standby power is required.
Torex XC6210B452MR-G	4.5V fixed output, 200mA rating, 25µA I_Q, no auto-discharge, SOT-25 package (2.9mm × 2.8mm).	Larger footprint and lack of discharge path limit use in space-constrained, fast-sequencing designs; lower PSRR (65dB @ 1kHz) increases susceptibility to switching noise.	Consider only for cost-sensitive, non-sequencing applications where board area and discharge are not constraints - not suitable for RF or wearable timing-critical use cases.

Compared with AP7353D-45FS4-7, AP7361D-45FS4-7 trades 7µA higher quiescent current for 200mA extra output headroom, while XC6210B452MR-G sacrifices 25% current capability, 25dB PSRR, and discharge functionality to fit legacy SOT-25 layouts - making AP7353D-45FS4-7 optimal for size-, noise-, and sequencing-sensitive 4.5V rail generation.

Availability

AP7353D-45FS4-7 is available at Aetrix Electronics and suitable for RF power amplifier biasing, camera ISP power sequencing, portable media player audio codec supplies, and wearable optical sensor analog front-ends requiring stable component supply, long-term lifecycle assurance, and traceable sourcing.

Supply support for AP7353D-45FS4-7 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 protection solutions for consumer, industrial, and automotive markets.

The AP7353 series belongs to Diodes' precision LDO portfolio, engineered specifically for noise-sensitive portable electronics requiring ultra-low quiescent current, high PSRR, and fast transient response in sub-1mm² packages.

FAQ

What is the minimum input voltage required for AP7353D-45FS4-7 to regulate 4.5V output at 250mA?

The typical dropout voltage is 114mV at 250mA and 4.5V output, so minimum input is 4.5V + 0.114V = 4.614V. However, the device guarantees operation down to 2.0V input - meaning it cannot sustain 4.5V output below ~4.614V. For full 250mA load, VIN must exceed 4.614V; lower inputs reduce maximum deliverable current.

Does AP7353D-45FS4-7 require an external discharge resistor?

No. AP7353D-45FS4-7 integrates an auto-discharge NMOS switch (35Ω typical on-resistance) that activates automatically when EN is pulled low. This eliminates need for external resistors, reduces BOM count, and ensures consistent discharge timing - unlike non-D variants (e.g., AP7353-45FS4-7) which lack this feature.

Can AP7353D-45FS4-7 be used with ceramic capacitors smaller than 1µF?

Yes - the device is stable with ≥0.7µF ceramic output capacitance, accounting for temperature, DC bias, and tolerance derating. However, 1µF (X7R/X5R) is recommended to ensure margin across all conditions and optimize transient response. Using <0.7µF risks instability or excessive overshoot during load steps.

Is the exposed pad (EP) on AP7353D-45FS4-7 electrically connected to GND?

No - the EP is thermally conductive but electrically isolated. Diodes' datasheet explicitly states it "must not be used as GND electrode function alone." It should be soldered to a large copper pour for heat dissipation and may be left floating or connected to GND *only* for thermal enhancement - never as the sole GND return path.

AP7353D-45FS4-7 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):: 5.5V

Voltage - Output (Min/Fixed):: 4.5V

Voltage - Output (Max):: -

Voltage Dropout (Max):: 0.117V @ 250mA

Current - Output:: 250mA

Current - Quiescent (Iq):: 27 µA

Current - Supply (Max):: -

PSRR:: 90dB ~ 70dB (100Hz ~ 10kHz)

Control Features:: Current Limit, Enable

Protection Features:: Over Current, Over Temperature, Short Circuit

Operating Temperature:: -40°C ~ 85°C (TA)

Grade:: Automotive

Qualification:: AEC-Q100

Mounting Type:: Surface Mount

Supplier Device Package:: X2-DFN1010-4 (Type B)

AP7353D-45FS4-7 FAQ

1.How can I place an order for AP7353D-45FS4-7 through Aetrix?

Please submit a Request for Quotation (RFQ) for AP7353D-45FS4-7 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 AP7353D-45FS4-7 reliable?

The price and inventory of AP7353D-45FS4-7 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for AP7353D-45FS4-7 is usually 5 days.

3.What payment methods are accepted for AP7353D-45FS4-7?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for AP7353D-45FS4-7 transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for AP7353D-45FS4-7?

AP7353D-45FS4-7 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your AP7353D-45FS4-7 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 AP7353D-45FS4-7?

For technical support, including AP7353D-45FS4-7 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your AP7353D-45FS4-7 requirements.

6.How does Aetrix verify that AP7353D-45FS4-7 is sourced from the original manufacturer or authorized distributors?

All AP7353D-45FS4-7 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 AP7353D-45FS4-7 meets industry standards.

7.What is the process for return or replacement of AP7353D-45FS4-7?

All AP7353D-45FS4-7 units undergo pre-shipment inspection (PSI). If there is an issue with AP7353D-45FS4-7, 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 AP7353D-45FS4-7 part is unused and in its original packaging.

Return procedure for AP7353D-45FS4-7:

1.Submit a request within 90 days.

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

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