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Diodes Incorporated AP2121N-1.8TRG1
- Part No.:
- AP2121N-1.8TRG1
- Manufacturer:
- Diodes Incorporated
- Package:
- TO-236-3, SC-59, SOT-23-3
- Datasheet:
-
AP2121N-1.8TRG1.pdf
- Description:
- IC REG LINEAR 1.8V 200MA SOT23-3
- Quantity:
- Payment:
- Shipping:
Inventory:1,914
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Product details
Overview
AP2121N-1.8TRG1 from Diodes Incorporated is a high-speed, extremely low-noise 1.8V 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 (CE), supports ceramic capacitors as low as 1µF, and targets precision power rails in portable RF and imaging subsystems.
For engineers reviewing the AP2121N-1.8TRG1 datasheet, AP2121N-1.8TRG1 pinout, AP2121N-1.8TRG1 application, or AP2121N-1.8TRG1 equivalent, key selection criteria include ultra-low noise for analog/RF stages, tight load/line regulation (12mV/4mV typ), standby current of 0.1µA, and compatibility with battery-powered systems requiring stable 1.8V core or I/O supply.
Technical Context
The AP2121N-1.8TRG1 employs a CMOS-based error amplifier architecture with internal voltage reference and resistor network for fixed 1.8V output. Its high PSRR (70dB @ 1kHz) and low thermal drift (±100 ppm/°C) stem from precision bandgap design and optimized feedback loop stability.
It features integrated current limiting (50mA short-circuit protection), CE-controlled shutdown with 2.5–10MΩ internal pull-down, and operation across –40°C to +85°C ambient. Dropout behavior is linearly scalable with load-250mV max at 200mA-enabling efficient use of single-cell Li-ion or dual-cell alkaline inputs.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Voltage | 1.8V ±2% - ensures reliable logic-level compliance for 1.8V microcontrollers and memory interfaces |
| Max Output Current | 200mA continuous - sufficient for powering baseband processors or sensor signal chains |
| Dropout Voltage | 150mV typ @ 100mA - enables operation down to VIN = 1.95V, extending battery runtime |
| RMS Output Noise | 30µVrms (10Hz–100kHz) - minimizes phase noise in RF synthesizers and jitter in ADC clocking |
| PSRR | 70dB @ 1kHz - suppresses switching noise from upstream DC/DC converters feeding the LDO input |
| Quiescent Current | 25µA typ - preserves battery life during system sleep modes without compromising wake-up speed |
| Enable Threshold | CE "High" ≥1.5V - compatible with 1.8V GPIOs; "Low" ≤0.25V ensures robust shutdown under noise |
Pinout & Package
SOT-23-5 package: 5-pin surface-mount, 1.3mm × 2.9mm footprint, 1.45mm height, JEDEC MO-178 compliant, thermally enhanced with exposed pad (not electrically connected).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (CE) | Chip Enable input | Active-high digital control: drives LDO into <0.1µA standby when pulled low; internal 5MΩ pull-down ensures default-off safety |
| 2 (GND) | Power ground reference | Primary return path for output current and internal bias; must be low-impedance connection to minimize noise coupling |
| 3 (VIN) | Input voltage supply | Accepts 2V–6V input; requires ≥1µF ceramic capacitor placed within 2mm for EMI suppression and transient response |
| 4 (NC) | No connection | Unbonded die pad; must remain floating-no routing or soldering permitted |
| 5 (VOUT) | Regulated output | Delivers stable 1.8V; requires ≥1µF ceramic output capacitor (ESR 0.01–100Ω) for loop stability and load transient recovery |
Key Features
| Feature | Design Value |
|---|---|
| Ultra-low noise regulation | 30µVrms output noise enables clean power for RF transceivers and high-resolution ADCs without external filtering |
| Sub-µA standby mode | 0.1µA shutdown current extends shelf life and enables long-term battery-backed monitoring applications |
| Low-ESR capacitor support | Stable with 1µF ceramic caps (0.01–100Ω ESR) - eliminates need for bulk tantalum or electrolytic capacitors |
| High accuracy over temperature | ±2% initial tolerance and ±100 ppm/°C drift ensure consistent 1.8V rail across industrial temperature range |
| Fast transient response | Load step recovery <10µs (50mA → 100mA) - maintains voltage integrity during processor burst activity |
Applications
| Mobile Baseband Power | Wireless Sensor Node Core Supply |
|---|---|
|
Use Scenario: Powers 1.8V I/O banks and RF front-end bias circuits in LTE/5G handsets. IC Role / Device Role / Timing Role: Primary low-noise post-regulator after buck converter; supplies critical analog blocks requiring minimal supply-induced jitter. Use Value: 70dB PSRR attenuates switcher ripple; 30µVrms noise prevents EVM degradation in transmit paths. |
Use Scenario: Provides regulated 1.8V to ultra-low-power MCU, BLE radio, and environmental sensors in battery-operated IoT nodes. IC Role / Device Role / Timing Role: Always-on LDO with CE-controlled shutdown; enables deep-sleep current <1µA system-wide. Use Value: 0.1µA standby current extends 10-year battery life; 1µF ceramic cap compatibility reduces BOM count and board area. |
| Digital Camera Image Signal Processor | Portable Medical Diagnostic Module |
|
Use Scenario: Supplies 1.8V core voltage to high-speed image signal processors (ISP) in compact action cameras. IC Role / Device Role / Timing Role: Low-dropout, fast-transient LDO handling dynamic ISP load steps during auto-exposure and HDR frame capture. Use Value: 250mV dropout at 200mA allows direct use of partially discharged Li-ion cells; <10µs transient recovery prevents image artifacts. |
Use Scenario: Delivers clean 1.8V to precision analog front-ends (AFE) and low-noise amplifiers in handheld ECG or pulse oximeters. IC Role / Device Role / Timing Role: Noise-sensitive analog power rail; isolated from digital switching noise via high PSRR and dedicated ground path. Use Value: 30µVrms noise avoids baseline wander in µV-level bio-signals; ±2% accuracy ensures calibrated measurement repeatability. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar LDO regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| AP7343-18SAG-7 | Successor part: same 1.8V output, 300mA rating, 250mV dropout @ 200mA, 25µVrms noise, and AEC-Q100 Grade 1 qualification | Supports automotive-grade reliability and PPAP; wider VIN range (1.7–6V); improved thermal resistance (θJA = 170°C/W vs. 250°C/W) | Select for new designs requiring extended lifecycle support, higher reliability, or automotive qualification. |
| MCP1700T-1802E/TT | Microchip 1.8V LDO: 250mA output, 600mV dropout @ 250mA, 35µVrms noise, 1.6µA quiescent current, no enable pin | Lacks CE control; higher dropout limits usable input range; lower IQ benefits always-on wearables but sacrifices controllability | Choose only if enable functionality is unnecessary and lowest possible quiescent current is prioritized over noise and dropout. |
Compared with AP2121N-1.8TRG1, AP7343-18SAG-7 offers superior automotive readiness and thermal performance, while MCP1700T-1802E/TT trades enable control and low-noise operation for ultra-low IQ-making AP2121N-1.8TRG1 optimal for cost-sensitive, non-automotive portable designs needing balanced noise, dropout, and controllability.
Availability
AP2121N-1.8TRG1 is available at Aetrix Electronics and suitable for mobile communications, portable imaging, wireless sensing, and medical diagnostics requiring stable component supply and proven low-noise LDO performance.
Supply support for AP2121N-1.8TRG1 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, with manufacturing certified to IATF 16949 and product definitions aligned to AEC-Q standards.
The AP2121 series belongs to Diodes' high-performance LDO portfolio, engineered specifically for battery-powered devices demanding ultra-low noise, low dropout, and precise voltage regulation in space-constrained applications.
FAQ
Is AP2121N-1.8TRG1 recommended for new designs?
No. Diodes Incorporated explicitly states "THE AP2121 IS NOT RECOMMENDED FOR NEW DESIGNS. PLEASE USE THE AP7343." This reflects end-of-life planning and migration to the enhanced AP7343 family, which offers improved specifications, automotive qualification, and longer-term supply assurance. AP2121N-1.8TRG1 remains available for legacy support and existing production ramps.
What is the minimum input voltage required for stable 1.8V output at 200mA?
Per datasheet Section 7 (AP2121-1.8 Electrical Characteristics), dropout voltage is 250mV max at 200mA. Therefore, minimum stable input voltage is 1.8V + 0.25V = 2.05V. The recommended operating range starts at VIN = 2.0V, but marginally below 2.05V risks dropout and output collapse under full load.
Can AP2121N-1.8TRG1 operate with a 0.47µF output capacitor?
No. The datasheet mandates "minimum output capacitance required for stability should be more than 1µF" with ESR between 0.01Ω and 100Ω. A 0.47µF capacitor violates the minimum value requirement and risks oscillation, poor load transient response, and potential damage under dynamic conditions. Only ≥1µF X5R/X7R ceramic capacitors are validated.
Does the NC pin (Pin 4) require PCB routing or grounding?
No. Pin 4 is explicitly designated "NC (No Connection)" in the datasheet pin description table and functional block diagram. It is an unconnected die pad with no internal bond wire. Routing, soldering, or grounding this pin may cause mechanical stress, thermal imbalance, or unintended parasitic coupling-PCB layout must leave it completely unconnected and unmasked.
AP2121N-1.8TRG1 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):
- 1.8V
- 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-1.8TRG1 FAQ
1.How can I place an order for AP2121N-1.8TRG1 through Aetrix?
Please submit a Request for Quotation (RFQ) for AP2121N-1.8TRG1 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-1.8TRG1 reliable?
The price and inventory of AP2121N-1.8TRG1 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for AP2121N-1.8TRG1 is usually 5 days.
3.What payment methods are accepted for AP2121N-1.8TRG1?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for AP2121N-1.8TRG1 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for AP2121N-1.8TRG1?
AP2121N-1.8TRG1 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your AP2121N-1.8TRG1 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-1.8TRG1?
For technical support, including AP2121N-1.8TRG1 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your AP2121N-1.8TRG1 requirements.
6.How does Aetrix verify that AP2121N-1.8TRG1 is sourced from the original manufacturer or authorized distributors?
All AP2121N-1.8TRG1 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-1.8TRG1 meets industry standards.
7.What is the process for return or replacement of AP2121N-1.8TRG1?
All AP2121N-1.8TRG1 units undergo pre-shipment inspection (PSI). If there is an issue with AP2121N-1.8TRG1, 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-1.8TRG1 part is unused and in its original packaging.
Return procedure for AP2121N-1.8TRG1:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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