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Diodes Incorporated AP2138N-2.1TRG1
- Part No.:
- AP2138N-2.1TRG1
- Manufacturer:
- Diodes Incorporated
- Package:
- TO-236-3, SC-59, SOT-23-3
- Datasheet:
-
AP2138N-2.1TRG1.pdf
- Description:
- IC REG LINEAR 250MA SOT23-3
- Quantity:
- Payment:
- Shipping:
Inventory:6,000
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Product details
Overview
AP2138N-2.1TRG1 from Diodes Incorporated is a fixed-output 2.1V CMOS low-dropout (LDO) voltage regulator in SOT-23-3 package, delivering up to 250mA output current with ±2% output voltage accuracy, 1.0µA typical quiescent current, and 25mV typical dropout at 10mA load. It serves as a precision power source for battery-powered microcontrollers and sensor interfaces where ultra-low standby power is critical.
For engineers reviewing the AP2138N-2.1TRG1 datasheet, AP2138N-2.1TRG1 pinout, AP2138N-2.1TRG1 application, or AP2138N-2.1TRG1 equivalent, key selection criteria include its 2.1V fixed output, SOT-23-3 footprint compatibility, 250mA load capability, thermal resistance of 81.9°C/W, and absence of enable control-distinguishing it from the AP2139 series.
Technical Context
This LDO employs a CMOS pass transistor with integrated voltage reference and error amplifier to maintain regulation across input voltages from 2.5V to 6.0V and ambient temperatures from –40°C to +85°C. Its architecture delivers stable 2.1V output with ±100ppm/°C temperature coefficient and 6mV typical line regulation.
No enable circuit is present-unlike the AP2139-making it a simple three-terminal regulator. The device relies on external 1µF input and ≥1µF output ceramic capacitors (ESR 0.01–100Ω) for stability, with no internal discharge path or logic control required.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Voltage | 2.100V ±2% - tightly regulated fixed output suitable for 2.1V I/O domains or low-voltage analog rails |
| Quiescent Current | 1.0µA typical - enables multi-year battery life in always-on sensor nodes and wearables |
| Max Output Current | 250mA - supports moderate-power peripherals like BLE radios or small displays without thermal derating in SOT-23-3 |
| Dropout Voltage | 25mV typical at 10mA - allows operation down to VIN = 2.125V while maintaining regulation |
| Load Regulation | 25mV typical (1–100mA) - ensures <12mV output shift across 99% of rated load range |
| Line Regulation | 6mV typical (2.5–6.0V input) - minimizes sensitivity to battery voltage sag during discharge |
| Temp Coefficient | ±100ppm/°C - contributes ≤±0.17% output drift over –40°C to +85°C junction range |
Pinout & Package
AP2138N-2.1TRG1 uses the SOT-23-3 surface-mount package (3-pin, 1.3mm × 2.9mm footprint, 1.0mm height), optimized for space-constrained portable PCBs. Thermal resistance is 81.9°C/W (junction-to-case) and 250°C/W (junction-to-ambient).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 (GND) | Ground reference | Primary return path for output current and internal bias; must connect to low-impedance ground plane |
| 2 (VOUT) | Regulated output | Delivers stable 2.1V to load; requires ≥1µF ceramic capacitor placed adjacent to pin for stability |
| 3 (VIN) | Input supply | Accepts 2.5–6.0V unregulated input; requires 1µF ceramic capacitor within 5mm of this pin |
Key Features
| Feature | Design Value |
|---|---|
| Ultra-low quiescent current | 1.0µA typical - reduces battery drain to <9mAh/year at 2.1V, enabling decade-scale operation in coin-cell devices |
| High output accuracy | ±2% over temperature and line - eliminates need for post-regulation trimming in precision analog signal chains |
| Low dropout performance | 25mV at 10mA - extends usable battery range by >150mV compared to standard LDOs in Li-ion and alkaline systems |
| Stable with ceramic capacitors | Supports 1µF–10µF X5R/X7R ceramics (0.01–100Ω ESR) - avoids costly tantalum or electrolytic alternatives |
| Robust thermal design | θJA = 250°C/W in SOT-23-3 - sustains full 250mA output at TA ≤ +65°C with minimal copper area |
Applications
| Wearable Health Sensors | IoT Edge Node Microcontrollers |
|---|---|
Use Scenario: Continuous ECG/PPG monitoring powered by CR2032 coin cell. IC Role / Device Role / Timing Role: Primary 2.1V supply for analog front-end and ultra-low-power MCU core. Use Value: 1.0µA quiescent current enables >5-year battery life; ±2% accuracy maintains ADC reference integrity across temperature. |
Use Scenario: Battery-backed environmental sensor node transmitting via LoRaWAN every 10 minutes. IC Role / Device Role / Timing Role: Standby power rail for MCU and RF transceiver during sleep cycles. Use Value: Low dropout allows operation until battery reaches 2.125V, maximizing energy extraction from primary cells. |
| Portable Medical Diagnostic Tools | Low-Power Industrial Transmitters |
Use Scenario: Handheld glucose meter using AAA alkaline batteries. IC Role / Device Role / Timing Role: Stable 2.1V bias for electrochemical sensor interface and display driver. Use Value: 6mV line regulation prevents measurement drift during battery voltage decay from 1.5V to 0.9V per cell. |
Use Scenario: Wireless pressure transmitter in remote oilfield instrumentation. IC Role / Device Role / Timing Role: Power source for 32-bit ARM Cortex-M0+ and 2.4GHz sub-GHz transceiver IC. Use Value: Ceramic-capacitor compatibility simplifies BOM and improves long-term reliability in high-vibration environments. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar fixed-output LDO applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| AP7354-21SA-7 | Successor part: 2.1V output, 300mA rating, 0.6µA IQ, SOT-23-3, AEC-Q100 qualified | Supports automotive-grade reliability and extended temperature range (–40°C to +125°C) | Select when new designs require longer product lifecycle support or automotive qualification. |
| MCP1700-2102E/TO | 2.1V output, 250mA, 1.6µA IQ, TO-92 package (through-hole), higher θJA (200°C/W) | Larger footprint and lower thermal efficiency; suited for prototyping or legacy through-hole assemblies | Choose only for manual assembly or where SOT-23 reflow is unavailable. |
Compared with AP2138N-2.1TRG1, AP7354-21SA-7 offers lower quiescent current and automotive qualification but requires validation for legacy board layouts; MCP1700-2102E/TO provides identical electrical specs in through-hole form but sacrifices thermal performance and board space efficiency.
Availability
AP2138N-2.1TRG1 is available at Aetrix Electronics and suitable for wearable health sensors, IoT edge nodes, portable medical tools, and low-power industrial transmitters requiring stable component supply and long-term obsolescence management.
Supply support for AP2138N-2.1TRG1 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 AP2138 series belongs to Diodes' ultra-low-IQ LDO portfolio, designed specifically for battery-powered portable electronics where minimizing standby power and maximizing runtime are primary system requirements.
FAQ
Is AP2138N-2.1TRG1 pin-compatible with other AP2138 variants?
Yes-AP2138N-2.1TRG1 shares identical SOT-23-3 pinout (GND-VOUT-VIN) and electrical behavior with all AP2138 fixed-output versions (1.2V–4.0V). Only the output voltage differs; no layout change is needed when switching between variants.
What is the minimum input voltage required to maintain regulation at 250mA load?
At 250mA, the typical dropout voltage is 750mV (per DS37428 Rev. 6–3, p.9). Therefore, minimum VIN = 2.1V + 0.75V = 2.85V to sustain regulation. Below this, output voltage drops linearly with input.
Can AP2138N-2.1TRG1 be used with aluminum polymer capacitors?
No-aluminum polymer capacitors typically have ESR below 10mΩ, which falls outside the 0.01–100Ω ESR range specified for stability. Only ceramic (X5R/X7R) or certain tantalum capacitors meeting the ESR requirement are recommended.
Why does Diodes recommend AP7354 instead of AP2138 for new designs?
AP7354 offers improved specifications-including 0.6µA IQ, 300mA output, AEC-Q100 qualification, and enhanced PSRR-while maintaining SOT-23-3 compatibility. Diodes discontinued AP2138 for new designs to consolidate support on the higher-performance, longer-lifecycle AP7354 platform.
AP2138N-2.1TRG1 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:
- Active
- Output Configuration:
- Positive
- Output Type:
- Fixed
- Number of Regulators:
- 1
- Voltage - Input (Max):
- 6V
- Voltage - Output (Min/Fixed):
- -
- Voltage - Output (Max):
- -
- Voltage Dropout (Max):
- -
- Current - Output:
- 250mA
- Current - Quiescent (Iq):
- 1.5 µA
- Current - Supply (Max):
- -
- PSRR:
- -
- Control Features:
- -
- Protection Features:
- -
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SOT-23-3
AP2138N-2.1TRG1 FAQ
1.How can I place an order for AP2138N-2.1TRG1 through Aetrix?
Please submit a Request for Quotation (RFQ) for AP2138N-2.1TRG1 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 AP2138N-2.1TRG1 reliable?
The price and inventory of AP2138N-2.1TRG1 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for AP2138N-2.1TRG1 is usually 5 days.
3.What payment methods are accepted for AP2138N-2.1TRG1?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for AP2138N-2.1TRG1 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for AP2138N-2.1TRG1?
AP2138N-2.1TRG1 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your AP2138N-2.1TRG1 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 AP2138N-2.1TRG1?
For technical support, including AP2138N-2.1TRG1 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your AP2138N-2.1TRG1 requirements.
6.How does Aetrix verify that AP2138N-2.1TRG1 is sourced from the original manufacturer or authorized distributors?
All AP2138N-2.1TRG1 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 AP2138N-2.1TRG1 meets industry standards.
7.What is the process for return or replacement of AP2138N-2.1TRG1?
All AP2138N-2.1TRG1 units undergo pre-shipment inspection (PSI). If there is an issue with AP2138N-2.1TRG1, 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 AP2138N-2.1TRG1 part is unused and in its original packaging.
Return procedure for AP2138N-2.1TRG1:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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