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Diodes Incorporated AP2121AK-2.8TRE1
- Part No.:
- AP2121AK-2.8TRE1
- Manufacturer:
- Diodes Incorporated
- Package:
- SC-74A, SOT-753
- Datasheet:
-
AP2121AK-2.8TRE1.pdf
- Description:
- IC REG LINEAR 2.8V 200MA SOT23-5
- Quantity:
- Payment:
- Shipping:
Inventory:2,990
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Product details
Overview
AP2121AK-2.8TRE1 from Diodes Incorporated is a high-speed, extremely low-noise 2.8V fixed-output LDO regulator in SOT-23-3 package, delivering up to 200mA output current with 150mV typical dropout at 100mA, 30µVrms output noise (10Hz–100kHz), and ±2% output voltage accuracy. It serves as a precision local power rail for noise-sensitive analog and RF circuitry in portable battery-powered systems.
For engineers reviewing the AP2121AK-2.8TRE1 datasheet, AP2121AK-2.8TRE1 pinout, AP2121AK-2.8TRE1 application, or AP2121AK-2.8TRE1 equivalent, key selection criteria include dropout performance under 100mA load, RMS noise floor in audio/RF bands, CE input logic thresholds, thermal resistance in SOT-23-3, and compatibility with 1µF ceramic output capacitors.
Technical Context
The AP2121AK-2.8TRE1 integrates a CMOS-based error amplifier, precision voltage reference, and current-limit protection in a single-die architecture optimized for fast transient response. Its internal chip-enable circuit enables active-high shutdown with 0.1µA standby current and 2.5–10MΩ internal pull-down resistance on CE.
Designed for stable operation with low-ESR ceramic capacitors ≥1µF, it achieves 70dB PSRR at 1kHz and maintains ±12mV load regulation across 1–80mA while exhibiting excellent line regulation (±4mV over 3.3–6V input range) and temperature coefficient of ±280µV/°C.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Voltage | 2.8V ±2% - ensures stable biasing for 2.8V I/O domains and RF front-end ICs |
| Max Output Current | 200mA continuous - supports moderate-power microcontrollers and sensor signal chains |
| Dropout Voltage | 150mV typ. @ 100mA - enables operation from Li-ion cells down to 2.95V while maintaining regulation |
| RMS Noise | 30µVrms (10Hz–100kHz) - minimizes phase noise in VCOs and SNR degradation in ADCs |
| PSRR | 70dB typ. @ 1kHz - suppresses switching noise from upstream DC/DC converters |
| Quiescent Current | 25µA typ. - extends battery life in always-on sensor nodes and wearables |
| Enable Threshold | VCE(HI) = 1.5V min., VCE(LO) = 0.25V max. - compatible with 1.8V/3.3V GPIO control without level shifters |
Pinout & Package
SOT-23-3 package: 3-pin surface-mount plastic package with 0.95mm pitch, JEDEC TO-236AB outline, and θJA = 250°C/W. Exposed pad not present; thermal path relies on PCB copper area.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (VIN) | Input voltage supply | Accepts 2.0–6.0V input; requires ≥1µF ceramic bypass capacitor adjacent to pin |
| 2 (GND) | Ground reference | Common return for input/output paths and error amplifier; must connect to low-impedance ground plane |
| 3 (VOUT) | Regulated output | Delivers 2.8V ±2%; requires ≥1µF ceramic output capacitor with ESR 0.01–100Ω for stability |
Key Features
| Feature | Design Value |
|---|---|
| Low-noise regulation | 30µVrms output noise enables clean power for RF transceivers and high-resolution ADCs |
| Ultra-low quiescent current | 25µA operating current allows >1-year battery life in coin-cell-powered IoT endpoints |
| Fast transient response | Stable under rapid load steps up to 100mA with minimal undershoot/overshoot |
| Low-ESR capacitor support | Stable with 1µF ceramic output caps - eliminates need for bulk tantalum or electrolytic capacitors |
| High PSRR at audio frequencies | 70dB rejection at 1kHz prevents audible switching noise coupling into audio amplifiers |
Applications
| Mobile Phone Baseband Power | Wireless Headset Audio Supply |
|---|---|
|
Use Scenario: Providing clean 2.8V rail to baseband processor I/O banks and memory interfaces in LTE/5G smartphones. IC Role / Device Role / Timing Role: Local LDO regulator supplying noise-sensitive digital I/O circuits requiring tight voltage tolerance and fast load transient recovery. Use Value: ±2% output accuracy and 70dB PSRR prevent data corruption during burst transmission; 150mV dropout extends usable battery range. |
Use Scenario: Powering MEMS microphones and Class-D audio amplifiers in Bluetooth headsets. IC Role / Device Role / Timing Role: Low-noise analog supply rail decoupling RF interference from sensitive audio signal paths. Use Value: 30µVrms noise floor preserves microphone SNR; 25µA quiescent current enables multi-week standby time. |
| Digital Camera Image Sensor Bias | Portable Medical Pulse Oximeter |
|
Use Scenario: Delivering regulated 2.8V to CMOS image sensor analog front-end and ADC reference circuitry. IC Role / Device Role / Timing Role: Precision analog power source ensuring consistent pixel response and low fixed-pattern noise. Use Value: ±12mV load regulation prevents gain drift across exposure modes; 1µF ceramic compatibility simplifies compact camera module layout. |
Use Scenario: Supplying optical sensor and analog signal conditioning circuitry in handheld pulse oximeters. IC Role / Device Role / Timing Role: Ultra-low-noise, low-quiescent LDO enabling accurate photoplethysmography (PPG) signal acquisition. Use Value: 30µVrms noise avoids masking weak AC PPG signals; 0.1µA shutdown current maximizes disposable 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 |
|---|---|---|---|
| AP7343-28W5-7 | Successor device: 200mA, 2.8V, 120mV dropout @ 100mA, 20µVrms noise, SOT-23-5 with CE pin | Requires 5-pin layout; adds enable control and improved noise performance | Preferred for new designs requiring lower noise or explicit enable functionality |
| MCP1700-2802E/TO | 250mA, 2.8V, 178mV dropout @ 250mA, 30µVrms, SOT-23-3, but 4µA quiescent current (higher than AP2121's 25µA) | Higher IQ reduces battery runtime in ultra-low-power sleep modes | Consider only if higher output current margin is required and noise/PSRR match is acceptable |
Compared with AP2121AK-2.8TRE1, AP7343-28W5-7 offers lower noise and modern qualification, while MCP1700-2802E/TO trades slightly higher dropout for greater current headroom-neither matches the exact combination of 25µA IQ, 150mV dropout, and 30µVrms in SOT-23-3.
Availability
AP2121AK-2.8TRE1 is available at Aetrix Electronics and suitable for mobile phone baseband power, wireless headset audio supply, digital camera image sensor bias, and portable medical pulse oximeter applications requiring stable component supply and long-term sourcing continuity.
Supply support for AP2121AK-2.8TRE1 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-reliability power management, signal integrity, and protection solutions for consumer, industrial, and automotive markets.
The AP2121 series belongs to Diodes' high-speed LDO product line, engineered specifically for battery-powered portable electronics demanding ultra-low noise, low dropout, and minimal quiescent current in space-constrained SOT-23 packages.
FAQ
Is AP2121AK-2.8TRE1 qualified for automotive use?
No. The AP2121AK-2.8TRE1 is not AEC-Q100 qualified. Diodes states that automotive-grade variants require specific change control, PPAP capability, and IATF 16949 manufacturing-these are not applicable to this SOT-23-3 commercial-grade part. For automotive applications, contact Diodes directly for qualified alternatives like the AP7361 series.
What is the minimum output capacitance required for stability?
The AP2121AK-2.8TRE1 requires a minimum 1µF ceramic output capacitor with ESR between 0.01Ω and 100Ω. Stability is guaranteed across this range; X5R or X7R dielectrics are recommended. Larger values improve transient response but are not required for basic stability.
Does AP2121AK-2.8TRE1 have an enable pin?
No. The AP2121AK-2.8TRE1 is the SOT-23-3 variant and lacks an enable (CE) pin. Only SOT-23-5 and CSP-4 versions include CE functionality. This 3-pin version operates continuously when VIN is within specification and has no shutdown mode.
Why does Diodes state "NOT RECOMMENDED FOR NEW DESIGNS"?
Diodes recommends migrating to the AP7343 series due to its superior specifications: lower noise (20µVrms vs. 30µVrms), lower dropout (120mV vs. 150mV), and enhanced process control. However, AP2121AK-2.8TRE1 remains fully supported for existing designs and legacy production with no announced obsolescence date.
AP2121AK-2.8TRE1 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):
- 2.8V
- 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:
- Enable
- Protection Features:
- Over Current
- Operating Temperature:
- -40°C ~ 85°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SOT-23-5
AP2121AK-2.8TRE1 FAQ
1.How can I place an order for AP2121AK-2.8TRE1 through Aetrix?
Please submit a Request for Quotation (RFQ) for AP2121AK-2.8TRE1 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 AP2121AK-2.8TRE1 reliable?
The price and inventory of AP2121AK-2.8TRE1 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for AP2121AK-2.8TRE1 is usually 5 days.
3.What payment methods are accepted for AP2121AK-2.8TRE1?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for AP2121AK-2.8TRE1 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for AP2121AK-2.8TRE1?
AP2121AK-2.8TRE1 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your AP2121AK-2.8TRE1 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 AP2121AK-2.8TRE1?
For technical support, including AP2121AK-2.8TRE1 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your AP2121AK-2.8TRE1 requirements.
6.How does Aetrix verify that AP2121AK-2.8TRE1 is sourced from the original manufacturer or authorized distributors?
All AP2121AK-2.8TRE1 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 AP2121AK-2.8TRE1 meets industry standards.
7.What is the process for return or replacement of AP2121AK-2.8TRE1?
All AP2121AK-2.8TRE1 units undergo pre-shipment inspection (PSI). If there is an issue with AP2121AK-2.8TRE1, 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 AP2121AK-2.8TRE1 part is unused and in its original packaging.
Return procedure for AP2121AK-2.8TRE1:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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