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

Diodes Incorporated AP7351D-25FS4-7B

Name: AP7351D-25FS4-7B
Brand: Diodes Incorporated
SKU: AP7351D-25FS4-7B
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: AP7351D-25FS4-7B

Manufacturer:: Diodes Incorporated

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

Package:: 4-XDFN Exposed Pad

Datasheet:: AP7351D-25FS4-7B.pdf

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

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Product details

Overview

AP7351D-25FS4-7B from Diodes Incorporated is a 2.5V fixed-output, 150mA ultra-low quiescent current (0.5µA typical) LDO regulator in X2-DFN1010-4 (Type B) package with enable control, ±1% output voltage accuracy at +25°C, and 60dB PSRR at 1kHz - designed for power management in wearable electronics and IoT sensor modules.

For engineers reviewing the AP7351D-25FS4-7B datasheet, AP7351D-25FS4-7B pinout, AP7351D-25FS4-7B application, or AP7351D-25FS4-7B equivalent, key selection criteria include dropout voltage (0.22V typ. at 150mA), standby current (0.02µA), EN logic thresholds (VIH ≥1.0V, VIL ≤0.4V), and thermal resistance (θJA = 237°C/W).

Technical Context

The AP7351D-25FS4-7B integrates a precision voltage reference, error amplifier, current-limit circuit, and active output discharge path. Its internal resistor network fixes VOUT to 2.5V, eliminating external feedback components.

Enable functionality supports system-level power sequencing: EN high (≥1.0V) activates regulation; EN low (≤0.4V) forces shutdown with 0.02µA standby current and 35Ω active discharge resistance to rapidly collapse VOUT.

Key Specifications

Parameter	Value and Actual Design Meaning
Output Voltage	Fixed 2.5V ±1% at +25°C; ±2% over −40°C to +85°C - ensures stable MCU core or sensor bias supply.
Max Output Current	150mA - sufficient for BLE SoCs, MEMS sensors, and low-power microcontrollers.
Quiescent Current	0.5µA typical - extends battery life in always-on wearables and remote sensors.
Dropout Voltage	0.22V typical at 150mA - enables operation down to VIN = 2.72V while maintaining 2.5V output.
PSRR	60dB at 1kHz - suppresses switching noise from adjacent DC/DC converters.
EN Thresholds	V_IH ≥ 1.0V, V_IL ≤ 0.4V - compatible with 1.8V/3.3V GPIO without level-shifting.
Thermal Resistance	θ_JA = 237°C/W (X2-DFN1010-4) - requires minimal PCB copper area for thermal management in space-constrained designs.

Pinout & Package

X2-DFN1010-4 (Type B) package: 1.0mm × 1.0mm, 0.65mm pitch, exposed thermal pad (EP) - optimized for ultra-compact wearable PCBs with high thermal efficiency when EP is connected to GND plane.

Pin/Terminal	Circuit Role	Design Meaning
PIN1 (VOUT)	Regulated output node	Delivers 2.5V ±1% to load; requires 0.1µF ceramic capacitor placed adjacent to pin for stability.
PIN2 (GND)	Power ground reference	Primary return path for input/output currents; must connect directly to low-impedance ground plane.
PIN3 (EN)	Active-high enable control	Drives regulator ON/OFF; floating state prohibited; 0.02µA shutdown current enables zero-power sleep modes.
PIN4 (VIN)	Input power supply	Accepts 1.4V–5.5V; minimum 2.72V required for full 150mA at 2.5V output due to dropout.
EP (Exposed Pad)	Thermal dissipation path	Not electrically functional; soldered to GND copper pour to reduce θ_JA and improve reliability under load.

Key Features

Feature	Design Value
Ultra-low quiescent current	0.5µA typical enables >1-year battery life in coin-cell-powered IoT nodes.
Active output discharge	35Ω internal discharge path collapses VOUT within microseconds after EN deactivation - prevents back-powering of upstream circuits.
Wide input voltage range	1.4V–5.5V supports single-cell Li-ion, LiFePO₄, or multi-cell alkaline sources without pre-regulation.
High PSRR at 1kHz	60dB attenuation of ripple from switching regulators - critical for noise-sensitive analog sensors and RF front-ends.
±1% output accuracy	Tight tolerance reduces need for calibration in precision ADC references and voltage-controlled oscillators.

Applications

Wearable Fitness Tracker

IoT Environmental Sensor Node

Use Scenario: Continuous heart-rate monitoring using optical sensor and low-power MCU in wrist-worn device.

IC Role / Device Role / Timing Role: Primary 2.5V supply for analog front-end and MCU core, enabling <1µA sleep current.

Use Value: 0.5µA quiescent current extends CR2032 battery life beyond 12 months in always-on mode.

Use Scenario: Battery-powered temperature/humidity sensor transmitting data via LoRaWAN every 10 minutes.

IC Role / Device Role / Timing Role: Stable 2.5V rail for precision ADC and RF transceiver during brief transmit bursts.

Use Value: 60dB PSRR prevents switching noise from LoRa PA from corrupting 16-bit sensor readings.

Wireless Earbud Charging Case

Smart Camera Module

Use Scenario: Charging case powering embedded battery gauge and Bluetooth LE controller.

IC Role / Device Role / Timing Role: Low-noise 2.5V supply for fuel-gauge IC and BLE SoC during charging status reporting.

Use Value: ±1% output accuracy ensures consistent battery SOC estimation across temperature (-40°C to +85°C).

Use Scenario: Compact USB-C camera module with image sensor and ISP requiring clean 2.5V bias.

IC Role / Device Role / Timing Role: Dedicated LDO for sensor analog supply, isolated from noisy digital rails.

Use Value: 0.22V dropout allows operation from 2.72V input - maximizes usable voltage range of single-cell Li-ion battery.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
MCP1700-2502E/TO	Same 2.5V output, but 1.6µA quiescent current (3.2× higher); no active discharge; SOT23-5 package.	Lacks fast VOUT discharge - unsuitable where back-powering must be avoided during power-down sequences.	Choose if board space permits larger SOT23-5 and active discharge is unnecessary.
Torex XC6219B251MR-G	2.5V output, 1µA quiescent current, 0.25V dropout at 100mA, but no EN pin - always-on operation only.	No enable control eliminates power sequencing capability; requires external MOSFET for shutdown.	Choose only for simple always-on loads where EN functionality is not required.

Compared with MCP1700-2502E/TO and XC6219B251MR-G, the AP7351D-25FS4-7B uniquely combines ultra-low I_Q (0.5µA), active discharge (35Ω), and EN control in a 1.0mm² DFN - making it optimal for space- and energy-constrained portable systems requiring precise power sequencing.

Availability

AP7351D-25FS4-7B is available at Aetrix Electronics and suitable for wearable electronics, IoT sensor nodes, and wireless communication modules requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for AP7351D-25FS4-7B 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, manufacturing, and distribution operations across Asia, Europe, and the Americas.

The AP7351D belongs to Diodes' ultra-low-I_Q LDO family, engineered specifically for extended-battery-life applications in wearables, medical patches, and edge IoT endpoints where micropower efficiency and small footprint are mandatory.

FAQ

What is the minimum input voltage required to maintain 2.5V output at 150mA load?

The AP7351D-25FS4-7B has a typical dropout voltage of 0.22V at 150mA. Therefore, the minimum input voltage is 2.5V + 0.22V = 2.72V. At lower VIN, output regulation degrades; operation below 1.4V is prohibited per Absolute Maximum Ratings.

Does the AP7351D-25FS4-7B require an external pull-up on the EN pin?

No external pull-up is required. The EN pin has no internal pull-up; however, it must never be left floating. For always-on operation, tie EN directly to VIN. For controlled enable, drive it actively high (≥1.0V) or low (≤0.4V) using a GPIO or logic signal.

Can the AP7351D-25FS4-7B be used with ceramic capacitors smaller than 0.1µF?

No. The datasheet specifies stability with ≥0.1µF ceramic output capacitance (X5R/X7R). Using smaller values risks instability and poor transient response. Input capacitor must also be ≥0.1µF ceramic, placed adjacent to VIN and GND pins.

Is the exposed pad (EP) of the X2-DFN1010-4 package electrically connected to GND?

No. The exposed pad is thermally conductive only and not electrically tied to any internal node. It must be soldered to a GND copper pour for thermal performance but should not be used as a functional GND connection - the dedicated PIN2 remains the sole electrical ground terminal.

AP7351D-25FS4-7B 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):: 5.5V

Voltage - Output (Min/Fixed):: 2.5V

Voltage - Output (Max):: -

Voltage Dropout (Max):: 0.48V @ 150mA

Current - Output:: 150mA

Current - Quiescent (Iq):: 1 µA

Current - Supply (Max):: -

PSRR:: 60dB (1kHz)

Control Features:: Current Limit, Enable

Protection Features:: Over Current

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

Grade:: Automotive

Qualification:: AEC-Q100

Mounting Type:: Surface Mount

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

AP7351D-25FS4-7B FAQ

1.How can I place an order for AP7351D-25FS4-7B through Aetrix?

Please submit a Request for Quotation (RFQ) for AP7351D-25FS4-7B 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 AP7351D-25FS4-7B reliable?

The price and inventory of AP7351D-25FS4-7B are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for AP7351D-25FS4-7B is usually 5 days.

3.What payment methods are accepted for AP7351D-25FS4-7B?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for AP7351D-25FS4-7B transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for AP7351D-25FS4-7B?

AP7351D-25FS4-7B orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your AP7351D-25FS4-7B 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 AP7351D-25FS4-7B?

For technical support, including AP7351D-25FS4-7B datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your AP7351D-25FS4-7B requirements.

6.How does Aetrix verify that AP7351D-25FS4-7B is sourced from the original manufacturer or authorized distributors?

All AP7351D-25FS4-7B 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 AP7351D-25FS4-7B meets industry standards.

7.What is the process for return or replacement of AP7351D-25FS4-7B?

All AP7351D-25FS4-7B units undergo pre-shipment inspection (PSI). If there is an issue with AP7351D-25FS4-7B, 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 AP7351D-25FS4-7B part is unused and in its original packaging.

Return procedure for AP7351D-25FS4-7B:

1.Submit a request within 90 days.

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

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