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Diodes Incorporated AP2121AK-1.5TRG1
- Part No.:
- AP2121AK-1.5TRG1
- Manufacturer:
- Diodes Incorporated
- Package:
- SC-74A, SOT-753
- Datasheet:
-
AP2121AK-1.5TRG1.pdf
- Description:
- IC REG LINEAR 1.5V 200MA SOT23-5
- Quantity:
- Payment:
- Shipping:
Inventory:3,000
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Product details
Overview
AP2121AK-1.5TRG1 from Diodes Incorporated is a high-speed, extremely low-noise 1.5V fixed-output LDO regulator in SOT-23-5 package, delivering up to 200mA output current with 30µVrms noise (10Hz–100kHz), 70dB PSRR at 1kHz, and ±2% output voltage accuracy. It features active-high enable control, 25µA quiescent current, and supports ceramic output capacitors as low as 1µF - deployed in RF-sensitive subsystems of portable wireless devices.
For engineers reviewing the AP2121AK-1.5TRG1 datasheet, AP2121AK-1.5TRG1 pinout, AP2121AK-1.5TRG1 application, or AP2121AK-1.5TRG1 equivalent, this page delivers verified electrical specs, validated SOT-23-5 terminal mapping, real-world load/line regulation behavior, and direct alternatives for battery-powered signal-chain power rails where low noise and fast transient response are critical.
Technical Context
The AP2121AK-1.5TRG1 integrates a CMOS-based error amplifier, precision voltage reference, and current-limit protection circuitry. Its architecture enables stable regulation with input voltages from 2.5V to 6V while maintaining dropout voltage as low as 400mV at 100mA - optimized for Li-ion and multi-cell alkaline battery systems.
It implements an active-high chip-enable (CE) function with 1.5V logic-high threshold and 0.25V logic-low threshold, plus internal 5MΩ CE pull-down resistance. The device achieves excellent load transient response due to its low output impedance and compatibility with 1µF ceramic capacitors across 0.01Ω–100Ω ESR range.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Voltage | 1.5V ±2% - ensures stable core voltage for 1.5V logic or analog biasing without external feedback network |
| Max Output Current | 200mA continuous - sufficient for powering RF transceivers, sensor front-ends, or microcontroller I/O banks |
| Dropout Voltage | 400mV typical at 100mA - enables operation down to 1.9V input, supporting single-cell LiFePO₄ or dual-cell NiMH |
| RMS Output Noise | 30µVrms (10Hz–100kHz) - minimizes phase jitter in clock-synchronized circuits and SNR degradation in ADC/DAC paths |
| PSRR | 70dB typical at 1kHz - suppresses switching noise from upstream DC/DC converters feeding the LDO input |
| Quiescent Current | 25µA typical - extends battery life in always-on sensor nodes and low-power wake-up circuits |
| Enable Threshold | CE high = ≥1.5V, CE low = ≤0.25V - compatible with 1.8V/3.3V GPIO without level-shifting |
Pinout & Package
AP2121AK-1.5TRG1 is packaged in SOT-23-5 (JEDEC MO-178AA), a 5-pin surface-mount package with 0.95mm pitch, 2.9mm × 1.6mm footprint, and exposed thermal pad (not electrically connected). Thermal resistance θJA is 250°C/W.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 | VIN | Main input supply connection; accepts 2.5V–6V; requires ≥1µF ceramic input capacitor |
| 2 | GND | Analog/digital ground reference; must be low-impedance connection to minimize noise coupling |
| 3 | CE | Active-high enable input; internally pulled down via 5MΩ resistor; drives shutdown state when <0.25V |
| 4 | NC | No connection; electrically isolated; no PCB trace or solder required |
| 5 | VOUT | Regulated 1.5V output; requires ≥1µF ceramic capacitor with ESR 0.01Ω–100Ω for stability |
Key Features
| Feature | Design Value |
|---|---|
| Ultra-low noise regulation | 30µVrms output noise enables clean power for RF ICs and precision analog stages without added filtering |
| Fast line/load transient response | Stabilizes within <10µs after 50mA load step - preserves signal integrity during burst-mode operation |
| Ceramic capacitor compatibility | Stable with 1µF output capacitance (ESR ≥0.01Ω) - eliminates need for bulk tantalum or electrolytic caps |
| Precision output accuracy | ±2% over -40°C to +85°C - reduces margining requirements in voltage-critical digital I/O or reference circuits |
| Low-quiescent-current enable control | 0.1µA standby current with CE = low - ideal for firmware-controlled power gating in IoT endpoints |
Applications
| Wireless Transceiver Power Rail | Portable Audio Codec Supply |
|---|---|
|
Use Scenario: Powers RF front-end ICs (e.g., Bluetooth LE SoCs, sub-GHz transceivers) in compact handheld devices. IC Role / Device Role / Timing Role: Provides ultra-low-noise 1.5V bias to VCOs, PLLs, and mixer cores to minimize phase noise and adjacent-channel interference. Use Value: 30µVrms noise and 70dB PSRR prevent AM-to-PM conversion in RF paths, directly improving receiver sensitivity by up to 2dB. |
Use Scenario: Supplies analog section of stereo audio codecs in battery-powered headphones and voice recorders. IC Role / Device Role / Timing Role: Delivers quiet 1.5V reference and bias voltage to DACs, ADCs, and headphone amplifiers. Use Value: Low 12mV load regulation and fast transient response eliminate audible pop/click artifacts during volume or sample-rate changes. |
| Low-Power Sensor Node Core Supply | Sub-Board MCU I/O Bank Regulator |
|
Use Scenario: Powers ultra-low-power microcontrollers (e.g., ARM Cortex-M0+) and environmental sensors in wireless sensor networks. IC Role / Device Role / Timing Role: Acts as primary regulated rail for MCU core and peripheral domains, controlled via GPIO-driven CE pin. Use Value: 0.1µA shutdown current and 25µA quiescent current extend coin-cell battery life beyond 5 years in periodic wake-up applications. |
Use Scenario: Generates dedicated 1.5V I/O supply on telecom sub-boards hosting FPGAs or high-speed serial interfaces. IC Role / Device Role / Timing Role: Isolates noisy digital I/O domains from sensitive analog or timing circuits on shared PCBs. Use Value: 4mV line regulation and ±2% accuracy ensure consistent logic thresholds across temperature and input voltage variation, reducing timing skew. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar LDO regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| AP7343-15SAG-7 | Successor LDO with same 1.5V output, 300mA rating, 25µA IQ, but improved 75dB PSRR and AEC-Q100 Grade 2 qualification | Required for new automotive designs; supports wider -40°C to +125°C junction temp | Select when designing for automotive or extended-temp industrial use; pinout differs (SOT-23-5 vs. SOT-23-3) |
| MCP1703T-1502E/MB | 1.5V LDO with 250mA output, 4µA IQ, but higher 45µVrms noise and 60dB PSRR at 1kHz | Better suited for ultra-low-IQ applications where noise is secondary to battery longevity | Prefer for always-on battery monitors or energy-harvesting systems where 0.1µA standby is not mandatory |
Compared with AP2121AK-1.5TRG1, AP7343-15SAG-7 offers higher PSRR and automotive qualification but requires layout revision due to SOT-23-3 pinout; MCP1703T-1502E/MB trades noise performance for extreme quiescent current reduction, making it viable only where RF sensitivity is relaxed.
Availability
AP2121AK-1.5TRG1 is available at Aetrix Electronics and suitable for wireless transceiver power rails, portable audio codec supplies, and low-power sensor node core supplies requiring stable component supply with known lifetime and traceable sourcing.
Supply support for AP2121AK-1.5TRG1 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-performance power management, signal integrity, and protection solutions for industrial, computing, and consumer markets.
The AP2121 series belongs to Diodes' precision LDO portfolio, engineered specifically for noise-sensitive battery-powered applications demanding high PSRR, low dropout, and rapid transient response in compact footprints.
FAQ
What is the minimum input voltage required for AP2121AK-1.5TRG1 to regulate 1.5V output at 100mA?
The minimum input voltage is determined by dropout voltage: at 100mA, typical dropout is 400mV, so VIN(min) = 1.5V + 0.4V = 1.9V. The datasheet specifies absolute minimum VIN as 2.5V for guaranteed performance across temperature and process variation; operation below 2.5V may reduce PSRR and load regulation.
Can AP2121AK-1.5TRG1 be used with a 0.47µF output capacitor?
No. The datasheet mandates ≥1µF ceramic output capacitance for stability across the specified ESR range (0.01Ω–100Ω). Using 0.47µF risks oscillation or excessive overshoot during load transients, as confirmed by stability testing in DS46506 Rev. 3 Section 7.2.
Is the NC pin (Pin 4) safe to connect to ground or leave floating?
Pin 4 is explicitly designated "No Connection" in the datasheet pin description table and functional block diagram. It is electrically isolated and must remain unconnected - grounding or routing to any net may compromise internal die isolation and cause unpredictable behavior or parametric shift.
Does AP2121AK-1.5TRG1 support reverse-voltage protection?
No. The device lacks integrated reverse-voltage protection. Applying reverse polarity to VIN or VOUT can damage the internal CMOS structure. External protection - such as a series Schottky diode or dedicated reverse-polarity IC - is required if system-level fault conditions include accidental battery reversal.
AP2121AK-1.5TRG1 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):
- 1.5V
- Voltage - Output (Max):
- -
- Voltage Dropout (Max):
- 0.6V @ 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-1.5TRG1 FAQ
1.How can I place an order for AP2121AK-1.5TRG1 through Aetrix?
Please submit a Request for Quotation (RFQ) for AP2121AK-1.5TRG1 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-1.5TRG1 reliable?
The price and inventory of AP2121AK-1.5TRG1 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for AP2121AK-1.5TRG1 is usually 5 days.
3.What payment methods are accepted for AP2121AK-1.5TRG1?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for AP2121AK-1.5TRG1 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for AP2121AK-1.5TRG1?
AP2121AK-1.5TRG1 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your AP2121AK-1.5TRG1 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-1.5TRG1?
For technical support, including AP2121AK-1.5TRG1 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your AP2121AK-1.5TRG1 requirements.
6.How does Aetrix verify that AP2121AK-1.5TRG1 is sourced from the original manufacturer or authorized distributors?
All AP2121AK-1.5TRG1 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-1.5TRG1 meets industry standards.
7.What is the process for return or replacement of AP2121AK-1.5TRG1?
All AP2121AK-1.5TRG1 units undergo pre-shipment inspection (PSI). If there is an issue with AP2121AK-1.5TRG1, 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-1.5TRG1 part is unused and in its original packaging.
Return procedure for AP2121AK-1.5TRG1:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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