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

Diodes Incorporated AP2121N-3.0TRE1

Name: AP2121N-3.0TRE1
Brand: Diodes Incorporated
SKU: AP2121N-3.0TRE1
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: AP2121N-3.0TRE1

Manufacturer:: Diodes Incorporated

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

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

Datasheet:: AP2121N-3.0TRE1.pdf

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

Quantity:: RFQ Add To RFQ list

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Inventory:3,772

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Product details

Overview

AP2121N-3.0TRE1 from Diodes Incorporated is a high-speed, extremely low-noise 3.0V fixed-output 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. It serves as a precision local power supply for noise-sensitive analog and RF circuitry in portable battery-powered systems.

For engineers reviewing the AP2121N-3.0TRE1 datasheet, AP2121N-3.0TRE1 pinout, AP2121N-3.0TRE1 application, or AP2121N-3.0TRE1 equivalent, key selection criteria include ultra-low noise performance, compatibility with 1µF ceramic output capacitors, high PSRR (70dB @ 1kHz), and standby current of 0.1µA - critical for always-on sensor nodes and low-power MCU core rails.

Technical Context

The AP2121N-3.0TRE1 integrates a CMOS-based error amplifier, precision voltage reference, and current-limit protection in a single-stage LDO architecture. Its internal resistor network fixes the output at 3.0V with ±2% tolerance over -40°C to +85°C ambient temperature and input voltage range of 2V to 6V.

It features active-high chip-enable control (not implemented in SOT-23-3 variant), supports fast load transient response due to low output impedance, and maintains stability with ceramic capacitors as low as 1µF and ESR between 0.01Ω and 100Ω - eliminating need for tantalum or electrolytic alternatives.

Key Specifications

Parameter	Value and Actual Design Meaning
Output Voltage	3.0V ±2% - ensures stable biasing for 3.0V logic interfaces and analog sensors without external feedback tuning
Max Output Current	200mA continuous - sufficient for powering microcontroller cores, RF transceivers, or small FPGA I/O banks
Dropout Voltage	150mV typ. @ 100mA - enables operation from 3.15V input, extending usable battery life in single-cell Li-ion or 3x alkaline systems
Output Noise	30µV_rms (10Hz–100kHz) - minimizes phase jitter in clock buffers and SNR degradation in ADC front-ends
PSRR	70dB @ 1kHz - suppresses switching noise from upstream DC/DC converters feeding the LDO input rail
Quiescent Current	25µA typ. - preserves battery capacity during sleep modes in wearable and IoT edge devices
Standby Current	0.1µA typ. - enables true shutdown when disabled via CE (not available on SOT-23-3 variant)

Pinout & Package

SOT-23-3 package: 3-pin surface-mount plastic package with 0.95mm pitch, JEDEC TO-236AB outline, thermal resistance θ_JA = 250°C/W, suitable for compact PCB layouts and automated assembly.

Pin	Circuit Role	Design Meaning
1 (VIN)	Input voltage supply	Accepts 2V–6V unregulated input; requires ≥1µF ceramic bypass capacitor for stability and noise filtering
2 (GND)	Ground reference	Low-impedance return path for load current and internal bias; must be connected to clean system ground plane
3 (VOUT)	Regulated output	Delivers stable 3.0V ±2% output; supports ≥1µF ceramic output capacitor with ESR 0.01Ω–100Ω

Key Features

Feature	Design Value
Ultra-low noise regulation	30µV_rms output noise enables use in PLL VCO supplies and high-resolution SAR ADC references
High PSRR at audio frequencies	70dB rejection at 1kHz allows co-location with noisy digital power domains without signal contamination
Low dropout with high current capability	150mV dropout at 100mA supports >200mA loads from marginal input sources like aging batteries
Ceramic capacitor compatibility	Stable with 1µF ceramic output caps eliminates need for larger, less reliable tantalum or aluminum electrolytics
Precision output accuracy	±2% over full temperature and load range reduces need for post-regulation trimming in production test

Applications

Wireless Sensor Node Power

Portable Audio Codec Supply

Use Scenario: Powering BLE SoC, MEMS accelerometer, and RF front-end in coin-cell–powered environmental monitor.

IC Role / Device Role / Timing Role: Primary 3.0V LDO supplying MCU core, radio transceiver, and analog sensor interface.

Use Value: 30µV_rms noise prevents RF desensitization; 0.1µA standby current extends 10-year battery life.

Use Scenario: Local regulation for stereo audio codec IC in Bluetooth headset with shared Li-ion battery rail.

IC Role / Device Role / Timing Role: Clean 3.0V analog supply for DAC/ADC section and headphone driver biasing.

Use Value: 70dB PSRR blocks switching noise from buck converter powering digital baseband, preserving THD+N < 0.01%.

Industrial IoT Edge Controller

Camera Module Bias Rail

Use Scenario: Powering ARM Cortex-M4 MCU and isolated CAN transceiver in DIN-rail mounted gateway.

IC Role / Device Role / Timing Role: Secondary LDO generating 3.0V for MCU I/O and CAN PHY interface from 5V system rail.

Use Value: ±2% output accuracy ensures reliable level-shifting across temperature; 200mA headroom supports firmware updates with full peripheral activation.

Use Scenario: Providing regulated 3.0V to image sensor analog front-end and ISP core in compact action camera.

IC Role / Device Role / Timing Role: Low-noise bias source for pixel array readout and analog signal chain amplification.

Use Value: 150mV dropout enables operation down to 3.15V input, maximizing runtime from 3.7V Li-Po cell under heavy video capture load.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
AP7343-30WG-7	Successor device: same 3.0V output, 300mA rating, 120mV dropout @ 100mA, 25µV_rms noise, SOT-23-3 package	Designed for new designs; qualified per AEC-Q100 Grade 2; supports wider input range (1.7V–6V)	Select for new projects requiring extended lifecycle support and automotive-grade reliability.
MCP1700-3002E/TO	Microchip 3.0V LDO: 250mA, 175mV dropout @ 250mA, 30µV_rms noise, SOT-23-3, but higher quiescent current (2.5µA)	Lacks AEC-Q qualification; lower PSRR (60dB @ 1kHz); no standby mode	Consider only for cost-sensitive industrial prototypes where automotive qualification is not required.

Compared with AP2121N-3.0TRE1, AP7343-30WG-7 offers lower dropout and automotive qualification for long-term design-in, while MCP1700-3002E/TO trades off PSRR and standby current for broader distributor availability - making AP2121N-3.0TRE1 most suitable for legacy systems where footprint and BOM continuity are prioritized over next-generation specs.

Availability

AP2121N-3.0TRE1 is available at Aetrix Electronics and suitable for wireless sensor nodes, portable audio subsystems, industrial IoT controllers, and camera module bias rails requiring stable component supply and proven field reliability.

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

The AP2121 series belongs to Diodes' high-performance LDO portfolio, engineered specifically for battery-powered portable electronics demanding ultra-low noise, high PSRR, and minimal quiescent current.

FAQ

Is AP2121N-3.0TRE1 recommended for new designs?

No - Diodes explicitly states "THE AP2121 IS NOT RECOMMENDED FOR NEW DESIGNS. PLEASE USE THE AP7343." This part remains available for legacy production and repair, but AP7343-30WG-7 is the designated replacement with improved specs and AEC-Q100 qualification. Designers initiating new projects should migrate to AP7343.

What is the minimum input voltage required for 3.0V output at 200mA load?

Based on typical 150mV dropout at 100mA and worst-case 500mV dropout at 200mA (per DS46506 Rev. 3-3, p.11), the minimum input voltage is 3.5V to guarantee 3.0V output at full 200mA load across temperature and process variation. For robust margin, 3.6V is recommended.

Can AP2121N-3.0TRE1 be used with a 0.47µF output capacitor?

No - the datasheet specifies a minimum output capacitance of >1µF with ESR between 0.01Ω and 100Ω for stability. Using 0.47µF risks oscillation or poor transient response. Ceramic capacitors of 1µF or greater (X5R/X7R, 6.3V rating) are mandatory per application note and typical circuit diagrams.

Does AP2121N-3.0TRE1 include enable functionality?

No - the "N" suffix and SOT-23-3 package indicate the no-enable variant. Pin 3 is VOUT, Pin 2 is GND, Pin 1 is VIN. Enable functionality is only present in SOT-23-5 and CSP-4 versions (e.g., AP2121K-3.0TRE1). This part operates continuously when input voltage is applied.

AP2121N-3.0TRE1 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-3.0TRE1 FAQ

1.How can I place an order for AP2121N-3.0TRE1 through Aetrix?

Please submit a Request for Quotation (RFQ) for AP2121N-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 AP2121N-3.0TRE1 reliable?

The price and inventory of AP2121N-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 AP2121N-3.0TRE1 is usually 5 days.

3.What payment methods are accepted for AP2121N-3.0TRE1?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for AP2121N-3.0TRE1 transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for AP2121N-3.0TRE1?

AP2121N-3.0TRE1 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your AP2121N-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 AP2121N-3.0TRE1?

For technical support, including AP2121N-3.0TRE1 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your AP2121N-3.0TRE1 requirements.

6.How does Aetrix verify that AP2121N-3.0TRE1 is sourced from the original manufacturer or authorized distributors?

All AP2121N-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 AP2121N-3.0TRE1 meets industry standards.

7.What is the process for return or replacement of AP2121N-3.0TRE1?

All AP2121N-3.0TRE1 units undergo pre-shipment inspection (PSI). If there is an issue with AP2121N-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 AP2121N-3.0TRE1 part is unused and in its original packaging.

Return procedure for AP2121N-3.0TRE1:

1.Submit a request within 90 days.

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

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