My Inquiry
My Account
Diodes Incorporated AP2121N-2.8TRG1
- Part No.:
- AP2121N-2.8TRG1
- Manufacturer:
- Diodes Incorporated
- Package:
- TO-236-3, SC-59, SOT-23-3
- Datasheet:
-
AP2121N-2.8TRG1.pdf
- Description:
- IC REG LINEAR 2.8V 200MA SOT23-3
- Quantity:
- Payment:
- Shipping:
Inventory:4,380
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
AP2121N-2.8TRG1 from Diodes Incorporated is a high-speed, extremely low-noise 2.8V fixed-output LDO regulator in SOT-23-5 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 circuitry in portable battery-powered systems.
For engineers reviewing the AP2121N-2.8TRG1 datasheet, AP2121N-2.8TRG1 pinout, AP2121N-2.8TRG1 application, or AP2121N-2.8TRG1 equivalent, key selection criteria include its ultra-low noise performance, 0.1µA standby current, 70dB PSRR at 1kHz, compatibility with 1µF ceramic output capacitors, and active-high enable control for power sequencing.
Technical Context
The AP2121N-2.8TRG1 employs a CMOS-based error amplifier architecture with internal voltage reference and resistor network for precise 2.8V regulation. Its current-limit protection activates at 50mA short-circuit threshold, and thermal shutdown safeguards operation under overload.
It features an active-high chip-enable (CE) input with 1.5V logic-high threshold and 0.25V logic-low threshold, enabling controlled power-up/down sequencing. The device supports stable operation with output capacitors as low as 1µF and ESR between 0.01Ω and 100Ω, eliminating need for tantalum or electrolytic types.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Voltage | 2.8V ±2% - ensures stable biasing for 2.8V-tolerant RF ICs and ADC references |
| Dropout Voltage | 150mV typ. @ 100mA - enables regulation from 2.95V input, extending battery runtime in single-cell Li-ion systems |
| RMS Output Noise | 30µVrms (10Hz–100kHz) - minimizes phase jitter in clock-synchronized signal chains |
| PSRR | 70dB typ. @ 1kHz - suppresses switching noise from upstream DC/DC converters feeding the LDO input |
| Quiescent Current | 25µA typ. - reduces no-load power loss in always-on sensor nodes and wearables |
| Standby Current | 0.1µA typ. - enables microamp-level system sleep states when CE = low |
| Output Current Limit | 50mA short-circuit current - provides safe fault containment without external current-sense circuitry |
Pinout & Package
SOT-23-5 package: 2.9mm × 1.6mm × 1.1mm body, surface-mount, RoHS-compliant, rated for -40°C to +85°C ambient operation.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (CE) | Chip Enable | Active-high digital control input; pulls down internally via 2.5–10MΩ resistor when unconnected |
| 2 (VIN) | Input Supply | Accepts 2.0V–6.0V input; requires ≥1µF ceramic capacitor for stability |
| 3 (GND) | Ground Reference | Common return path for input, output, and internal circuitry; must be low-impedance |
| 4 (NC) | No Connection | Internally unconnected; must remain floating-no external tie or routing |
| 5 (VOUT) | Regulated Output | Delivers 2.8V ±2% to load; requires ≥1µF ceramic capacitor with ESR 0.01–100Ω |
Key Features
| Feature | Design Value |
|---|---|
| Ultra-low noise regulation | 30µVrms output noise enables clean power for RF transceivers and high-resolution ADCs |
| Low dropout with high current capability | 150mV dropout at 100mA supports >200mA continuous output while maintaining regulation down to VIN = 2.95V |
| High PSRR across audio band | 70dB rejection at 1kHz suppresses ripple from buck converter switching frequencies and their harmonics |
| Minimal external component count | Stable with only 1µF input and 1µF output ceramic capacitors-no ESR tuning required |
| Controlled enable sequencing | Logic-compatible CE pin with 1.5V high-threshold allows direct interfacing with 1.8V/3.3V GPIOs |
Applications
| Mobile RF Front-End Power | Digital Camera Image Sensor Bias |
|---|---|
|
Use Scenario: Powering 2.8V LNA and mixer stages in 4G/5G handset front-end modules. IC Role / Device Role / Timing Role: Low-noise local regulator supplying critical RF analog blocks. Use Value: 30µVrms noise prevents reciprocal mixing degradation and maintains EVM < 2.5% at 256-QAM. |
Use Scenario: Providing bias voltage to CMOS image sensor analog core and column ADC drivers. IC Role / Device Role / Timing Role: Precision voltage source for pixel readout and analog signal chain reference. Use Value: ±2% output accuracy and 70dB PSRR ensure consistent sensor gain calibration and SNR > 62dB. |
| Wearable Health Monitor Analog Subsystem | Industrial IoT Edge Node Sensor Interface |
|
Use Scenario: Supplying EEG/ECG analog front-end amplifiers and 24-bit delta-sigma ADCs in compact wearables. IC Role / Device Role / Timing Role: Ultra-low-quiescent, low-noise power rail for biopotential signal conditioning. Use Value: 0.1µA standby current extends coin-cell life beyond 12 months in sleep mode; 30µVrms noise preserves µV-level bio-signal integrity. |
Use Scenario: Powering MEMS accelerometer, temperature sensor, and SAR ADC in battery-operated condition-monitoring nodes. IC Role / Device Role / Timing Role: Stable, low-drift supply for precision sensor excitation and digitization. Use Value: ±100ppm/°C tempco and 4mV line regulation minimize measurement drift across -40°C to +85°C industrial environments. |
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: same 2.8V output, 300mA rating, 25µA IQ, but improved 45dB PSRR @ 1MHz and AEC-Q100 Grade 2 qualification | Required for new automotive designs; supports higher-frequency noise suppression in ADAS camera modules | Select for new designs requiring extended temperature range, PPAP support, or enhanced high-frequency PSRR |
| MCP1700-2802E/TO | 200mA output, 6µA IQ, but 120µVrms noise and 55dB PSRR @ 1kHz - significantly higher noise and lower ripple rejection | Suitable for digital I/O rails where noise sensitivity is low, not for RF or precision analog | Choose only if ultra-low quiescent current dominates over noise/PSRR requirements |
Compared with AP2121N-2.8TRG1, AP7343-28W5-7 offers automotive qualification and better high-frequency PSRR but targets newer platforms, while MCP1700-2802E/TO trades noise performance for lower IQ-making AP2121N-2.8TRG1 optimal for legacy portable designs needing proven ultra-low-noise regulation.
Availability
AP2121N-2.8TRG1 is available at Aetrix Electronics and suitable for mobile phone RF subsystems, wearable health sensor interfaces, portable imaging devices, and industrial edge node analog power rails requiring stable component supply and long-term obsolescence management.
Supply support for AP2121N-2.8TRG1 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, low dropout, and minimal quiescent current.
FAQ
What is the maximum input voltage rating for AP2121N-2.8TRG1?
The absolute maximum input voltage is 6.5V, but recommended operating range is 2.0V to 6.0V. Operation above 6.0V risks exceeding junction temperature limits under load due to increased power dissipation, especially in SOT-23-5's 250°C/W θJA. For 6V input at 200mA, power dissipation reaches 640mW-requiring careful PCB thermal design.
Can AP2121N-2.8TRG1 operate with a 0.47µF output capacitor?
No. The datasheet specifies a minimum 1µF ceramic output capacitor with ESR between 0.01Ω and 100Ω for guaranteed stability. Using 0.47µF violates the stability criterion and may cause oscillation or poor transient response, particularly during load steps. Always use ≥1µF X5R/X7R ceramic capacitors placed within 2mm of VOUT and GND pins.
Is the NC pin (Pin 4) required to be left floating?
Yes. Pin 4 is internally unconnected in the SOT-23-5 variant of AP2121N-2.8TRG1. It must remain electrically floating-neither tied to GND, VIN, nor VOUT. Routing traces or soldering to this pin may introduce parasitic coupling or mechanical stress that affects thermal performance or long-term reliability.
Why does the datasheet state "not recommended for new designs"?
Diodes Incorporated has superseded AP2121N-2.8TRG1 with AP7343-28W5-7, which offers identical 2.8V output and pinout but adds AEC-Q100 qualification, improved 1MHz PSRR, and extended production support. AP2121N-2.8TRG1 remains fully functional and available for existing designs, but new projects should evaluate the AP7343 for long-term supply assurance and enhanced specs.
AP2121N-2.8TRG1 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):
- 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:
- -
- Protection Features:
- Over Current
- Operating Temperature:
- -40°C ~ 85°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SOT-23-3
AP2121N-2.8TRG1 FAQ
1.How can I place an order for AP2121N-2.8TRG1 through Aetrix?
Please submit a Request for Quotation (RFQ) for AP2121N-2.8TRG1 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-2.8TRG1 reliable?
The price and inventory of AP2121N-2.8TRG1 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for AP2121N-2.8TRG1 is usually 5 days.
3.What payment methods are accepted for AP2121N-2.8TRG1?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for AP2121N-2.8TRG1 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for AP2121N-2.8TRG1?
AP2121N-2.8TRG1 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your AP2121N-2.8TRG1 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-2.8TRG1?
For technical support, including AP2121N-2.8TRG1 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your AP2121N-2.8TRG1 requirements.
6.How does Aetrix verify that AP2121N-2.8TRG1 is sourced from the original manufacturer or authorized distributors?
All AP2121N-2.8TRG1 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-2.8TRG1 meets industry standards.
7.What is the process for return or replacement of AP2121N-2.8TRG1?
All AP2121N-2.8TRG1 units undergo pre-shipment inspection (PSI). If there is an issue with AP2121N-2.8TRG1, 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-2.8TRG1 part is unused and in its original packaging.
Return procedure for AP2121N-2.8TRG1:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
AP2121N-2.8TRG1 Tags
-
MIC5504-1.8YM5-TR
Microchip Technology
-
MIC5504-3.3YM5-TR
Microchip Technology
-
MIC5365-3.0YC5-TR
Microchip Technology
-
MIC5365-1.8YC5-TR
Microchip Technology
-
MIC5365-2.5YC5-TR
Microchip Technology
-
MIC5365-3.3YC5-TR
Microchip Technology
-
MIC5365-3.3YD5-TR
Microchip Technology
-
MIC5317-3.3YM5-TR
Microchip Technology
-
TLV1117LV33DCYR
Texas Instruments
-
MIC5317-3.3YMT-TZ
Microchip Technology
-
MIC5528-3.3YMT-TR
Microchip Technology
-
TLV75801PDRVR
Texas Instruments
Tech Hub
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.…
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…
Product Change Notification guide for electronic components, covering PCN meaning, PCN vs PDN/EOL, common change types, risk levels, form-fit-function review, engineering validation, BOM control, LTB/L…
A practical guide to blend door actuators, covering HVAC function, symptoms, location, AC and heater issues, reset and calibration, replacement cost, electrical diagnosis, compatibility checks, and rep…
Engineering guide to Raspberry Pi alternatives, covering chip-level differences, Orange Pi, ROCK, Jetson, Banana Pi, NanoPi, Compute Module, Pico, GPIO, camera, HAT compatibility, and replacement risks…
Engineering guide to dynamic load response testing for high-current buck converters, covering load step setup, slew rate, Vcore undershoot, overshoot, recovery time, probe location, output capacitors a…
Engineering guide to output capacitor selection for ASIC Vcore rails, covering bulk capacitors, polymer capacitors, MLCC decoupling, DC bias, ESR, ESL, placement, transient response and substitution ri…
Engineering guide to high-current ASIC Vcore rails, covering 12-phase buck architecture, PMBus control, dynamic load testing, output capacitor networks, smart power stage selection, thermal design and …
Voltage regulator guide covering linear, LDO, 7805, Zener, adjustable, buck, VRM and alternator regulators, with design checks, testing methods, troubleshooting and datasheet-based selection.
Amplifier guide covering voltage, current and power amplification, gain, feedback, amplifier classes, audio and RF applications, op-amp circuits, transimpedance amplifiers, datasheet selection and trou…
