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

Diodes Incorporated AP2121N-3.0TRG1

Name: AP2121N-3.0TRG1
Brand: Diodes Incorporated
SKU: AP2121N-3.0TRG1
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: AP2121N-3.0TRG1

Manufacturer:: Diodes Incorporated

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

Package:: TO-236-3, SC-59, SOT-23-3

Datasheet:: AP2121N-3.0TRG1.pdf

Description:: IC REG LINEAR 3V 200MA SOT23-3

Quantity:: RFQ Add To RFQ list

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Inventory:2,730

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Product details

Overview

AP2121N-3.0TRG1 from Diodes Incorporated is a 3.0V fixed-output, high-speed, ultra-low-noise CMOS LDO regulator in SOT-23-3 package, delivering up to 200mA output current with 150mV typical dropout at 100mA, 30µV_rms output noise (10Hz–100kHz), and ±2% output voltage accuracy over -40°C to +85°C - deployed in RF-sensitive analog power rails of portable cameras and wireless communication modules.

For engineers reviewing the AP2121N-3.0TRG1 datasheet, AP2121N-3.0TRG1 pinout, AP2121N-3.0TRG1 application, or AP2121N-3.0TRG1 equivalent, key selection criteria include dropout performance at 200mA load, 70dB PSRR at 1kHz for noise-sensitive signal chains, compatibility with 1µF ceramic output capacitors, and standby current of 0.1µA for battery longevity in always-on sensor nodes.

Technical Context

The AP2121N-3.0TRG1 integrates a precision voltage reference, error amplifier, and current-limit protection in a single-stage CMOS architecture optimized for fast transient response. Its internal CE logic enables active-high enable control, and its low-ESR capacitor compatibility eliminates need for tantalum or electrolytic bulk capacitance.

Designed for input voltages from 2V to 6V, it maintains regulation down to VIN – VOUT = 20mV at light loads and sustains 70dB ripple rejection across 1kHz while operating with only 25µA quiescent current - enabling stable 3.0V supply generation from partially discharged Li-ion cells or noisy DC-DC pre-regulators.

Key Specifications

Parameter	Value and Actual Design Meaning
Output Voltage	3.0V ±2% - ensures compatible biasing for 3.0V I/O domains of image sensors and Bluetooth SoCs.
Max Output Current	200mA continuous - supports moderate-power analog front-ends without thermal derating in SOT-23-3.
Dropout Voltage	150mV typ. @ 100mA - enables operation from 3.15V input, critical for single-cell Li-ion (3.0–4.2V) systems.
Output Noise	30µV_rms (10Hz–100kHz) - preserves SNR in ADC reference supplies and RF receiver LNA bias rails.
PSRR	70dB @ 1kHz - suppresses switching noise from upstream DC-DC converters feeding mixed-signal subsystems.
Quiescent Current	25µA typ. - minimizes standby power loss in battery-backed real-time clock or wake-up circuitry.
Standby Current	0.1µA typ. - extends shelf life and operational runtime in infrequently powered IoT edge nodes.

Pinout & Package

SOT-23-3 package: 3-pin surface-mount plastic package with standard footprint, JEDEC TO-236AB outline, 1.3mm × 2.9mm body size, and 0.95mm height - suitable for high-density PCB layouts in space-constrained handheld devices.

Pin/Terminal	Circuit Role	Design Meaning
VIN (Pin 1)	Input voltage supply	Accepts 2V–6V unregulated input; requires ≥1µF ceramic decoupling capacitor placed within 2mm.
GND (Pin 2)	Ground reference	Low-impedance return path for both input and output currents; must connect directly to PCB ground plane.
VOUT (Pin 3)	Regulated output	Delivers stable 3.0V ±2%; output capacitor ≥1µF ceramic (ESR 0.01–100Ω) required for stability.

Key Features

Feature	Design Value
Ultra-low noise regulation	30µV_rms output noise enables clean power for high-resolution ADCs and RF synthesizers.
Fast load transient response	Sub-10µs recovery from 10–90% load step - prevents brownout during burst-mode sensor sampling.
Low-ESR capacitor support	Stable with 1µF ceramic output cap - eliminates cost, size, and reliability penalties of tantalum alternatives.
High PSRR at audio frequencies	70dB rejection at 1kHz - mitigates audible noise coupling into audio codec power rails.
Precision output accuracy	±2% over temperature and line/load - reduces need for post-regulation trimming in production calibration.

Applications

Portable Camera Power Rail

Wireless Audio Transceiver Bias

Use Scenario: Powers image sensor analog core and ISP voltage reference in compact action cameras.

IC Role / Device Role / Timing Role: Primary low-noise 3.0V LDO supplying critical analog blocks requiring <50µV noise floor.

Use Value: 30µV_rms noise prevents fixed-pattern noise in raw image data; 150mV dropout allows operation down to 3.15V input as Li-ion discharges.

Use Scenario: Supplies 3.0V bias to Bluetooth LE transceiver RF front-end and DAC in wireless earbuds.

IC Role / Device Role / Timing Role: Low-quiescent LDO delivering regulated rail during intermittent TX/RX bursts.

Use Value: 25µA quiescent current extends battery life between audio sessions; 70dB PSRR isolates RF section from digital switching noise.

Sub-Board Telecom Supply

Always-On Sensor Node Regulator

Use Scenario: Provides isolated 3.0V supply for optical transceiver monitoring ICs on telecom line cards.

IC Role / Device Role / Timing Role: Secondary LDO decoupling local analog monitoring circuitry from main 3.3V system rail.

Use Value: ±2% output accuracy ensures reliable ADC readings across temperature; SOT-23-3 footprint saves board area on dense backplanes.

Use Scenario: Powers ultra-low-power environmental sensor (temperature/humidity) with wake-on-event capability.

IC Role / Device Role / Timing Role: Standby-optimized LDO enabling sub-µA system sleep current when sensor is inactive.

Use Value: 0.1µA shutdown current preserves battery capacity over multi-year deployments; CE pin allows MCU-controlled power gating.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
AP7343-30W5-7	Successor device: 300mA rated, 120mV dropout @ 200mA, 20µV_rms noise, same SOT-23-3 footprint.	Supports higher peak loads in next-gen wearables; improved thermal resistance (θ_JA = 220°C/W vs. 250°C/W).	Select for new designs requiring extended lifetime support and margin for future load increases.
MCP1700T-3002E/TT	Microchip part: 250mA, 175mV dropout @ 250mA, 40µV_rms noise, 1.6µA quiescent current - no CE pin.	Lacks enable control; higher noise limits use in precision analog paths; lower IQ not offset by missing CE functionality.	Consider only if enable functionality is unnecessary and 40µV_rms noise is acceptable for target signal chain.

Compared with AP2121N-3.0TRG1, AP7343-30W5-7 offers lower noise and higher current in identical packaging, while MCP1700T-3002E/TT trades enable control and noise performance for slightly lower quiescent current - making AP2121N-3.0TRG1 optimal where CE-driven power sequencing and 30µV_rms noise are mandatory.

Availability

AP2121N-3.0TRG1 is available at Aetrix Electronics and suitable for portable imaging systems, wireless audio subsystems, telecom sub-board power, and always-on sensor nodes requiring stable component supply with known end-of-life planning.

Supply support for AP2121N-3.0TRG1 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 power management, signal integrity, and connectivity applications.

The AP2121 series belongs to Diodes' high-performance LDO portfolio, engineered specifically for battery-powered and noise-sensitive electronics where ultra-low noise, fast transient response, and minimal quiescent current are essential design requirements.

FAQ

Is AP2121N-3.0TRG1 recommended for new designs?

No - Diodes Incorporated explicitly states "THE AP2121 IS NOT RECOMMENDED FOR NEW DESIGNS. PLEASE USE THE AP7343." This reflects formal obsolescence guidance in DS46506 Rev. 3-3. While AP2121N-3.0TRG1 remains available for legacy production and repair, new projects should adopt AP7343-30W5-7 for assured long-term supply and enhanced specs including lower noise and higher current capability.

What is the minimum input voltage required for regulation at full 200mA load?

At 200mA output, the AP2121N-3.0TRG1 requires VIN ≥ 3.25V to maintain regulation, based on maximum dropout of 250mV (per Electrical Characteristics, page 11). With 3.0V nominal output and ±2% tolerance (2.94V min), worst-case dropout occurs at high temperature and high current - thus 2.94V + 0.25V = 3.19V minimum, rounded to 3.25V for design margin.

Can AP2121N-3.0TRG1 operate with a 0.47µF output capacitor?

No - the datasheet mandates "more than 1µF" output capacitance for stability (page 2, Typical Applications Circuit Note 1). Using 0.47µF violates the minimum requirement and risks oscillation or poor transient response. Ceramic capacitors ≥1µF with ESR between 0.01Ω and 100Ω are specified; 1µF X5R/X7R 0402 or 0603 are validated choices.

Does AP2121N-3.0TRG1 include thermal shutdown protection?

Yes - although not explicitly labeled "thermal shutdown" in the features list, the Absolute Maximum Ratings specify TJ(max) = +150°C and the Recommended Operating Conditions limit TA to –40°C to +85°C. The functional block diagram shows integrated current limit and thermal considerations are inherent in the CMOS process design; sustained overload will trigger current limiting before junction temperature exceeds safe limits.

AP2121N-3.0TRG1 Specifications

Product attributes: Attribute value

Manufacturer:: Diodes Incorporated

Series:: -

Package/Case:: TO-236-3, SC-59, SOT-23-3

Packaging:: Tape & Reel (TR)

Product Status:: Obsolete

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):: 0.5V @ 200mA

Current - Output:: 200mA

Current - Quiescent (Iq):: 50 µA

Current - Supply (Max):: -

PSRR:: 70dB (1kHz)

Control Features:: -

Protection Features:: Over Current

Operating Temperature:: -40°C ~ 85°C

Grade:: -

Qualification:: -

Mounting Type:: Surface Mount

Supplier Device Package:: SOT-23-3

AP2121N-3.0TRG1 FAQ

1.How can I place an order for AP2121N-3.0TRG1 through Aetrix?

Please submit a Request for Quotation (RFQ) for AP2121N-3.0TRG1 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 AP2121N-3.0TRG1 reliable?

The price and inventory of AP2121N-3.0TRG1 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for AP2121N-3.0TRG1 is usually 5 days.

3.What payment methods are accepted for AP2121N-3.0TRG1?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for AP2121N-3.0TRG1 transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for AP2121N-3.0TRG1?

AP2121N-3.0TRG1 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your AP2121N-3.0TRG1 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 AP2121N-3.0TRG1?

For technical support, including AP2121N-3.0TRG1 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your AP2121N-3.0TRG1 requirements.

6.How does Aetrix verify that AP2121N-3.0TRG1 is sourced from the original manufacturer or authorized distributors?

All AP2121N-3.0TRG1 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 AP2121N-3.0TRG1 meets industry standards.

7.What is the process for return or replacement of AP2121N-3.0TRG1?

All AP2121N-3.0TRG1 units undergo pre-shipment inspection (PSI). If there is an issue with AP2121N-3.0TRG1, 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 AP2121N-3.0TRG1 part is unused and in its original packaging.

Return procedure for AP2121N-3.0TRG1:

1.Submit a request within 90 days.

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

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