Send an Inquiry

To receive a quote for your project, please fill in the following information, and we’ll get back to you promptly.

Submit Inventory List

Please fill in the following information, and we’ll get back to you promptly.

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

Diodes Incorporated AP2125K-3.0TRE1

Name: AP2125K-3.0TRE1
Brand: Diodes Incorporated
SKU: AP2125K-3.0TRE1
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

Compare

Part No.:: AP2125K-3.0TRE1

Manufacturer:: Diodes Incorporated

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

Package:: SC-74A, SOT-753

Datasheet:: AP2125K-3.0TRE1.pdf

Description:: IC REG LINEAR 3V 300MA SOT23-5

Quantity:: RFQ Add To RFQ list

Payment:

Shipping:

Inventory:3,037

Please send an inquiry. Send us your inquiry, and we will respond immediately.

Product details

Overview

AP2125K-3.0TRE1 from Diodes Incorporated is a 300mA, fixed 3.0V output CMOS low-dropout (LDO) regulator in SOT-23-5 package, featuring 50µV_rms output noise, 65mV dropout at 100mA, ±2% output voltage accuracy, and active-high enable control. It delivers stable power to noise-sensitive analog circuitry in portable battery-powered systems.

For engineers reviewing the AP2125K-3.0TRE1 datasheet, AP2125K-3.0TRE1 pinout, AP2125K-3.0TRE1 application, or AP2125K-3.0TRE1 equivalent, key selection criteria include ultra-low noise performance, sub-100mV dropout under load, 0.01µA shutdown current, compatibility with ceramic output capacitors, and thermal shutdown protection at +160°C.

Technical Context

The AP2125K-3.0TRE1 integrates a precision voltage reference, error amplifier, resistor network for fixed 3.0V output, CE-controlled enable logic, current-limit protection, and over-temperature shutdown circuitry. Its CMOS process enables low quiescent current (60µA typical) and extremely low noise operation without requiring external bypass capacitors.

It operates across input voltages from 3.5V to 6V (V_OUT + 0.5V minimum), supports output currents up to 300mA, and maintains ±100ppm/°C temperature coefficient and <15mV load regulation across full operating range (–40°C to +85°C).

Key Specifications

Parameter	Value and Actual Design Meaning
Output Voltage	Fixed 3.0V ±2% - ensures stable supply for 3.3V-tolerant I/O or 3.0V core logic without external feedback.
Max Output Current	300mA minimum - sufficient for powering microcontrollers, sensors, and RF front-ends in compact portable devices.
Dropout Voltage	65mV at 100mA - enables high efficiency when input is only 3.065V, extending battery runtime in single-cell Li-ion or dual-cell alkaline systems.
RMS Output Noise	50µV_rms (10Hz–100kHz) - minimizes phase jitter in clock buffers and preserves SNR in ADC/DAC signal chains.
Quiescent Current	60µA typical - reduces standby power loss in always-on subsystems such as real-time clocks or wake-up controllers.
Standby Current	0.01µA typical - enables multi-year shelf life in battery-backed IoT endpoints with infrequent wake cycles.
PSRR	65dB at 1kHz - suppresses switching noise from DC-DC converters feeding the LDO input, critical for mixed-signal SoCs.

Pinout & Package

SOT-23-5 package: 2.9mm × 1.6mm × 1.1mm body, gull-wing leads, RoHS-compliant, halogen-free "Green" construction.

Pin/Terminal	Circuit Role	Design Meaning
1	VIN	Main input supply connection; accepts 3.5V–6V; requires 1µF ceramic input capacitor for stability.
2	GND	Analog/digital ground reference; must be low-impedance connection to minimize noise coupling.
3	CE	Active-high enable input; logic high ≥1.5V enables regulation; logic low ≤0.4V places IC in 0.01µA shutdown mode.
4	NC	No internal connection; left unconnected per design - no routing or grounding required.
5	VOUT	Regulated 3.0V output; requires 1µF ceramic output capacitor with ESR <1Ω for transient response and PSRR optimization.

Key Features

Feature	Design Value
Ultra-low noise regulation	50µV_rms output noise enables clean power for RF receivers, audio codecs, and precision ADCs without added filtering.
High PSRR at 1kHz	65dB rejection of ripple from upstream switching regulators preserves signal integrity in hybrid power architectures.
Low dropout at full load	200mV dropout at 300mA allows operation from 3.2V input - compatible with partially discharged Li-ion cells (3.0–4.2V).
Ceramic capacitor compatible	Stable with 1µF X5R/X7R ceramics on input and output - eliminates need for costly tantalum or electrolytic capacitors.
Thermal shutdown with hysteresis	Shuts down at +160°C with +25°C hysteresis - prevents latch-up during sustained overload while enabling safe auto-recovery.

Applications

Wireless Handset Power

Portable Instrumentation

Use Scenario: Supplies 3.0V bias to GSM/CDMA RF transceivers and baseband processors in space-constrained handsets.

IC Role / Device Role / Timing Role: Primary low-noise post-regulator delivering clean VCC to sensitive RF sections and PLLs.

Use Value: 50µV_rms noise prevents reciprocal mixing and adjacent-channel interference; 65mV dropout extends talk time by 8–12% vs. legacy LDOs.

Use Scenario: Powers analog front-end (AFE), microcontroller, and display driver in handheld multimeters and data loggers.

IC Role / Device Role / Timing Role: Main system regulator providing stable 3.0V rail for precision measurement circuits and low-power MCU cores.

Use Value: ±2% output accuracy ensures consistent ADC reference scaling; 0.01µA shutdown current enables >5-year battery life in storage mode.

Notebook Subsystem Supply

PCMCIA Card Regulation

Use Scenario: Generates 3.0V for USB controller, card reader interface, or embedded security module in ultrabooks and 2-in-1 laptops.

IC Role / Device Role / Timing Role: Dedicated LDO for isolated peripheral domain, decoupled from noisy main CPU VRM.

Use Value: 65dB PSRR isolates USB PHY from CPU switching noise; SOT-23-5 footprint saves PCB area versus larger SO-8 alternatives.

Use Scenario: Provides regulated 3.0V to PCMCIA/CardBus peripherals such as wireless LAN adapters and smart card readers.

IC Role / Device Role / Timing Role: Hot-swap capable regulator with enable control for controlled power sequencing during card insertion/removal.

Use Value: CE pin enables firmware-controlled power gating; thermal shutdown protects against connector short-circuits during hot-plug events.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
MCP1700-3002E/TO	250mA max output, 175mV dropout at 250mA, 30µV_rms noise, TO-92 package	Limited to lower-current analog rails; through-hole mounting only	Select when board-level serviceability or legacy through-hole assembly is required, not for high-density SMT designs.
Torex XC6206P302MR-G	300mA, 3.0V, 150mV dropout at 100mA, 40µV_rms noise, SOT-23-3 (3-pin)	No enable pin; fixed output only; lacks shutdown control	Choose when enable functionality is unnecessary and PCB space is constrained - uses smaller 3-pin footprint but sacrifices power sequencing.

Compared with MCP1700-3002E/TO and XC6206P302MR-G, the AP2125K-3.0TRE1 uniquely balances 300mA capability, ultra-low noise, active enable control, and SOT-23-5 thermal performance - making it optimal for battery-powered systems requiring both precision regulation and intelligent power management.

Availability

AP2125K-3.0TRE1 is available at Aetrix Electronics and suitable for wireless handsets, portable instrumentation, notebook subsystems, and PCMCIA cards requiring stable component supply with guaranteed long-term sourcing.

Supply support for AP2125K-3.0TRE1 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, with emphasis on power management, signal integrity, and protection devices.

The AP2125 series belongs to Diodes' high-performance LDO portfolio, engineered specifically for battery-powered portable electronics where low noise, low dropout, and minimal quiescent current are critical system requirements.

FAQ

What is the minimum input voltage required for AP2125K-3.0TRE1 to maintain regulation?

The AP2125K-3.0TRE1 requires VIN ≥ VOUT + 0.5V = 3.5V for guaranteed regulation across temperature and load. At 100mA output, dropout is 65mV, so 3.065V input sustains 3.0V output - but 3.5V is the specified minimum per recommended operating conditions to ensure stability and accuracy over –40°C to +85°C.

Can AP2125K-3.0TRE1 be used with ceramic capacitors less than 1µF?

No. The datasheet specifies 1µF minimum for both CIN and COUT using X5R/X7R ceramic capacitors. Using smaller values risks instability, degraded PSRR, and poor transient response. The internal compensation is optimized for ≥1µF, and ESR must remain below 1Ω - achievable only with standard 0805 or 0603 1µF ceramics.

Does the NC pin (Pin 4) require any PCB layout consideration?

Pin 4 is internally unconnected and must remain floating - no trace, pad, or solder mask opening is needed. Do not route signals or ground near this pin; avoid placing vias or copper pours directly beneath it to prevent parasitic coupling. Standard SOT-23-5 layout guidelines apply for thermal and electrical performance.

How does thermal shutdown behave during continuous overload?

When junction temperature reaches +160°C, the AP2125K-3.0TRE1 disables output and enters thermal shutdown. It remains off until temperature drops by +25°C hysteresis (to ~+135°C), then automatically resumes regulation. This cycle prevents permanent damage but is not intended for continuous operation - sustained overload requires derating or heatsinking per θ_JA = 200°C/W (SOT-23-5).

AP2125K-3.0TRE1 Specifications

Product attributes: Attribute value

Manufacturer:: Diodes Incorporated

Series:: -

Package/Case:: SC-74A, SOT-753

Packaging:: Tape & Reel (TR)

Product Status:: Active

Output Configuration:: Positive

Output Type:: Fixed

Number of Regulators:: 1

Voltage - Input (Max):: 6V

Voltage - Output (Min/Fixed):: 3V

Voltage - Output (Max):: -

Voltage Dropout (Max):: 0.3V @ 300mA

Current - Output:: 300mA

Current - Quiescent (Iq):: 90 µA

Current - Supply (Max):: -

PSRR:: 65dB (100Hz ~ 1kHz)

Control Features:: Enable

Protection Features:: Over Current, Over Temperature

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

Grade:: -

Qualification:: -

Mounting Type:: Surface Mount

Supplier Device Package:: SOT-23-5

AP2125K-3.0TRE1 FAQ

1.How can I place an order for AP2125K-3.0TRE1 through Aetrix?

Please submit a Request for Quotation (RFQ) for AP2125K-3.0TRE1 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 AP2125K-3.0TRE1 reliable?

The price and inventory of AP2125K-3.0TRE1 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for AP2125K-3.0TRE1 is usually 5 days.

3.What payment methods are accepted for AP2125K-3.0TRE1?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for AP2125K-3.0TRE1 transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for AP2125K-3.0TRE1?

AP2125K-3.0TRE1 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your AP2125K-3.0TRE1 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 AP2125K-3.0TRE1?

For technical support, including AP2125K-3.0TRE1 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your AP2125K-3.0TRE1 requirements.

6.How does Aetrix verify that AP2125K-3.0TRE1 is sourced from the original manufacturer or authorized distributors?

All AP2125K-3.0TRE1 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 AP2125K-3.0TRE1 meets industry standards.

7.What is the process for return or replacement of AP2125K-3.0TRE1?

All AP2125K-3.0TRE1 units undergo pre-shipment inspection (PSI). If there is an issue with AP2125K-3.0TRE1, 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 AP2125K-3.0TRE1 part is unused and in its original packaging.

Return procedure for AP2125K-3.0TRE1:

1.Submit a request within 90 days.

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

Tech Hub

2026-08-28 SR Latch Explained: NOR and NAND Circuits, Truth Tables, and Applications

An SR latch stores one bit through cross-coupled feedback. This engineering reference covers NOR and NAND implementations, truth tables, forbidden-state recovery, gated operation, switch debouncing, fa…

2026-08-27 Latch Circuit: SR and D Latches, Truth Tables, Timing, and Applications

Latch circuits retain one bit through feedback. This technical reference covers SR and D latches, truth tables, transparency, timing limits, latch-versus-flip-flop behavior, applications and common log…

2026-08-21 What Is an LED Driver? Types, Circuits, Dimming, and Selection

An engineering guide to LED driver operation, constant-current and constant-voltage outputs, linear and switching topologies, dimming, IC selection, calculations, replacement compatibility, and fault c…

2026-08-18 Operational Amplifier (Op Amp): Basics, Configurations, Feedback and Applications

Operational amplifier guide covering op amp basics, feedback, ideal vs real op amps, common configurations, buffer circuits, offset, bias current, gain-bandwidth, slew rate, rail-to-rail limits and sel…

2026-08-14 Jumper Cables: How to Use, Connect and Choose Them Safely

Jumper cables guide covering safe connection order, red and black clamp placement, final ground connection, cable gauge, length, clamp quality, copper vs CCA cables, jump starter comparison and battery…

2026-08-11 LDO Regulator: Dropout Voltage, Noise, PSRR and Power Dissipation

LDO regulator guide covering low dropout voltage, power dissipation, thermal design, PSRR, output noise, capacitor stability, adjustable LDO circuits, LDO vs buck converter and datasheet selection chec…

2026-08-06 Conditional Access Module: CAM, CI/CI+ and DVB Security

Conditional Access Module guide covering CAM meaning, CI/CI+ interface, smart card authorization, DVB security workflow, TV and set-top box compatibility, internal electronics, ESD protection, connecto…

2026-08-03 Electronic Component Obsolescence: EOL Risks, Replacement Options and Last-Time Buy Strategy

Guide to electronic component obsolescence covering EOL risk, PCN/PDN notices, last-time buy planning, replacement options, form-fit-function validation, counterfeit risk and BOM lifecycle management.

2026-07-29 18650 Battery: Voltage, Capacity, Charging and Pack Design

18650 battery guide covering lithium-ion cell basics, 3.6V/3.7V voltage, 4.2V charging, mAh and Wh capacity, protected cells, chargers, BMS, series-parallel packs, holders, welding and sourcing checks.…

2026-07-27 Hall Effect Sensor: Working Principle, Types, Circuits and Applications

Hall effect sensor guide covering working principle, linear and digital sensors, Arduino circuits, current sensing, speed detection, automotive applications, A3144 examples, signal filtering and datash…