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Diodes Incorporated AP2121AK-2.8TRG1
- Part No.:
- AP2121AK-2.8TRG1
- Manufacturer:
- Diodes Incorporated
- Package:
- SC-74A, SOT-753
- Datasheet:
-
AP2121AK-2.8TRG1.pdf
- Description:
- IC REG LINEAR 2.8V 200MA SOT23-5
- Quantity:
- Payment:
- Shipping:
Inventory:3,000
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Product details
Overview
AP2121AK-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 integrates an active-high enable pin, supports ceramic capacitors as low as 1µF, and targets power-sensitive analog and RF subsystems in portable electronics.
For engineers reviewing the AP2121AK-2.8TRG1 datasheet, AP2121AK-2.8TRG1 pinout, AP2121AK-2.8TRG1 application, or AP2121AK-2.8TRG1 equivalent, key selection criteria include dropout performance under 100mA load, RMS noise floor for ADC/DAC reference rails, CE input threshold compatibility with 1.8V/3.3V logic, and thermal resistance in SOT-23-5 for ambient temperatures up to +85°C.
Technical Context
The AP2121AK-2.8TRG1 uses a CMOS-based error amplifier architecture with internal voltage reference and resistor network for precise 2.8V regulation. Its current-limit circuit provides 50mA short-circuit protection, and the chip-enable function allows full shutdown with 0.1µA standby current.
Designed for stability with low-ESR ceramic capacitors, it achieves 70dB PSRR at 1kHz and exhibits excellent transient response to both line (input voltage step) and load (output current step) variations-critical for powering noise-sensitive RF front-ends and precision sensor signal chains.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Voltage | 2.8V ±2% - ensures stable bias for 2.8V I/O domains and analog circuits across temperature and load. |
| Dropout Voltage | 150mV typ. @ 100mA - enables operation from 2.95V input, supporting single-cell Li-ion or dual-cell alkaline systems. |
| RMS Output Noise | 30µVrms (10Hz–100kHz) - minimizes jitter in clock buffers and quantization noise in 12-bit+ ADCs. |
| PSRR | 70dB typ. @ 1kHz - suppresses switching noise from upstream DC/DC converters feeding the LDO input. |
| Quiescent Current | 25µA typ. - extends battery life in always-on sensor nodes and low-power wake-up circuits. |
| Enable Threshold | VCE(HI) = 1.5V min., VCE(LO) = 0.25V max. - compatible with 1.8V GPIO without level-shifting. |
| Thermal Resistance θJA | 250°C/W (SOT-23-5) - limits junction temperature rise to ≤25°C above ambient at 100mA with no PCB copper pour. |
Pinout & Package
AP2121AK-2.8TRG1 is housed in a RoHS-compliant SOT-23-5 surface-mount package with standard lead pitch (0.95mm) and moisture sensitivity level (MSL) 1. The package supports reflow soldering per J-STD-020 and provides adequate thermal dissipation for continuous 200mA operation at +85°C ambient when mounted on ≥1in² 2-oz copper.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (VIN) | Input voltage supply | Accepts 2.0V–6.0V input; requires ≥1µF ceramic capacitor placed within 3mm of pin for EMI suppression and stability. |
| 2 (GND) | Power ground reference | Low-impedance return path for output current and internal bias; must connect directly to main system ground plane. |
| 3 (CE) | Active-high enable control | Drives internal pass transistor; logic high ≥1.5V enables regulation, logic low ≤0.25V disables output and reduces IQ to 0.1µA. |
| 4 (NC) | No connection | Internally unconnected; must remain floating-no external tie or capacitor allowed. |
| 5 (VOUT) | Regulated output voltage | Delivers 2.8V ±2% to load; requires ≥1µF ceramic output capacitor with ESR 0.01–100Ω for phase margin >45°. |
Key Features
| Feature | Design Value |
|---|---|
| Ultra-low noise output | 30µVrms (10Hz–100kHz) enables direct powering of RF transceivers and high-resolution data converters without additional filtering. |
| High PSRR at 1kHz | 70dB attenuation of input ripple preserves signal integrity in mixed-signal SoC power domains fed by noisy buck converters. |
| Low dropout at full load | 150mV typical dropout at 100mA allows efficient use of marginal input voltages, reducing heat generation vs. higher-dropout alternatives. |
| Stable with 1µF ceramic caps | Eliminates need for bulk tantalum or electrolytic capacitors, saving board space and improving reliability in portable designs. |
| Enable pin with pull-down | Integrated 2.5–10MΩ CE pull-down resistor ensures default-disable state during power-up, preventing unintended output activation. |
Applications
| Mobile RF Front-End Power | Digital Camera Image Sensor Bias |
|---|---|
|
Use Scenario: Powering 2.8V LNA and mixer stages in 4G/5G handset RF modules where supply noise directly impacts receiver sensitivity. IC Role / Device Role / Timing Role: Low-noise post-regulator supplying clean bias to RF ICs downstream of a switching DC/DC converter. Use Value: 30µVrms noise and 70dB PSRR prevent reciprocal mixing and maintain >1dB NF margin over full operating temperature range. |
Use Scenario: Providing stable 2.8V analog supply to CMOS image sensors in smartphone cameras during high-frame-rate video capture. IC Role / Device Role / Timing Role: Precision voltage source for pixel array analog bias and column ADC reference rails. Use Value: ±2% output accuracy and <12mV load regulation ensure consistent pixel response and reduced fixed-pattern noise across varying frame loads. |
| Wearable Biometric Sensor Hub | Industrial IoT Edge Node MCU Core Rail |
|
Use Scenario: Supplying 2.8V to ultra-low-power optical heart-rate sensors and analog front-end amplifiers in fitness trackers. IC Role / Device Role / Timing Role: Always-on LDO maintaining regulated rail during intermittent BLE transmission bursts. Use Value: 25µA quiescent current and fast load transient response (<10µs settling) minimize battery drain while preserving signal fidelity during motion artifacts. |
Use Scenario: Delivering 2.8V core voltage to ARM Cortex-M4 microcontrollers in battery-backed industrial gateways operating at -40°C to +85°C. IC Role / Device Role / Timing Role: Primary linear regulator for MCU VCORE, enabled via host processor GPIO during active mode. Use Value: 0.1µA shutdown current and guaranteed operation down to -40°C enable multi-year battery life in remote monitoring deployments. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar LDO regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| AP7343-28SAG-7 | Successor device: same 2.8V output, 300mA rating, 120mV dropout @ 150mA, 22µVrms noise, and improved PSRR (75dB @ 1kHz). | Pin-compatible SOT-23-5 drop-in replacement with tighter thermal specs (θJA = 220°C/W) and AEC-Q100 Grade 2 qualification available. | Select for new designs requiring extended lifetime, lower noise, or automotive qualification; legacy AP2121AK-2.8TRG1 remains viable for cost-sensitive consumer replacements. |
| MCP1700-2802E/TO | Microchip's 2.8V variant: 250mA output, 175mV dropout @ 250mA, 35µVrms noise, 65dB PSRR, and 1.8µA quiescent current in TO-92. | Through-hole TO-92 package only; lacks enable pin and ceramic-cap stability guarantee-requires ≥4.7µF output capacitance. | Consider only for prototyping or low-volume through-hole assemblies where SOT-23-5 reflow is unavailable; not suitable for space-constrained or high-reliability applications. |
Compared with AP7343-28SAG-7, AP2121AK-2.8TRG1 offers proven field reliability but higher dropout and noise; versus MCP1700-2802E/TO, it delivers superior noise performance and SMT manufacturability at the cost of higher quiescent current and no through-hole option.
Availability
AP2121AK-2.8TRG1 is available at Aetrix Electronics and suitable for mobile RF front-end power, digital camera image sensor bias, wearable biometric sensor hubs, and industrial IoT edge node MCU core rails requiring stable component supply with known thermal and noise behavior.
Supply support for AP2121AK-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 manufacturer of discrete semiconductors and analog ICs, specializing in power management, signal integrity, and protection solutions for consumer, industrial, and automotive markets.
The AP2121 series belongs to Diodes' high-performance LDO portfolio, engineered specifically for battery-powered devices demanding ultra-low noise, low dropout, and minimal quiescent current in compact packages.
FAQ
What is the maximum input voltage for AP2121AK-2.8TRG1?
The absolute maximum input voltage is 6.5V, but the recommended operating range is 2.0V to 6.0V. Operation above 6.0V risks permanent damage even if duration is brief; sustained operation above 5.5V increases thermal stress and reduces long-term reliability. Input voltage must remain ≥2.95V to maintain regulation at 100mA load due to 150mV dropout.
Can AP2121AK-2.8TRG1 be used with a 0.47µF output capacitor?
No-AP2121AK-2.8TRG1 requires a minimum 1µF ceramic output capacitor with ESR between 0.01Ω and 100Ω for guaranteed stability. Using 0.47µF violates the datasheet condition and may cause oscillation, especially under light load or high temperature. A 1µF X5R or X7R 0603 capacitor placed adjacent to pins 2 (GND) and 5 (VOUT) is the validated solution.
Does AP2121AK-2.8TRG1 have built-in reverse polarity protection?
No, AP2121AK-2.8TRG1 lacks reverse-voltage protection. Applying negative voltage to VIN or VOUT relative to GND can damage the internal CMOS structure. External protection-such as a series Schottky diode on VIN or a back-to-back MOSFET arrangement-is required in systems where input reversal is possible, e.g., hot-swap or battery-reversal scenarios.
Is AP2121AK-2.8TRG1 qualified for automotive applications?
AP2121AK-2.8TRG1 itself is not AEC-Q100 qualified. Diodes offers automotive-grade variants (e.g., AP2121AK-2.8TRG1-13) with PPAP documentation and IATF 16949 manufacturing, but this specific part number is intended for commercial-grade applications. For automotive use, contact Diodes directly to obtain the qualified version and associated change-control documentation.
AP2121AK-2.8TRG1 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-2.8TRG1 FAQ
1.How can I place an order for AP2121AK-2.8TRG1 through Aetrix?
Please submit a Request for Quotation (RFQ) for AP2121AK-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 AP2121AK-2.8TRG1 reliable?
The price and inventory of AP2121AK-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 AP2121AK-2.8TRG1 is usually 5 days.
3.What payment methods are accepted for AP2121AK-2.8TRG1?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for AP2121AK-2.8TRG1 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for AP2121AK-2.8TRG1?
AP2121AK-2.8TRG1 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your AP2121AK-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 AP2121AK-2.8TRG1?
For technical support, including AP2121AK-2.8TRG1 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your AP2121AK-2.8TRG1 requirements.
6.How does Aetrix verify that AP2121AK-2.8TRG1 is sourced from the original manufacturer or authorized distributors?
All AP2121AK-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 AP2121AK-2.8TRG1 meets industry standards.
7.What is the process for return or replacement of AP2121AK-2.8TRG1?
All AP2121AK-2.8TRG1 units undergo pre-shipment inspection (PSI). If there is an issue with AP2121AK-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 AP2121AK-2.8TRG1 part is unused and in its original packaging.
Return procedure for AP2121AK-2.8TRG1:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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