The **8140-AF5-D-R** is a specific electronic component, typically identified as a **Low Dropout (LDO) Voltage Regulator** or a **Voltage Detector/Reset IC**, most commonly manufactured by UTC (Unisonic Technologies Co.). Below is a detailed breakdown of its specifications, pinout, and characteristics. --- ### 1. General Specifications The part number suffix system usually denotes the voltage, package type, and packing method. | Feature | Description | | :--- | :--- | | **Component Type** | CMOS Voltage Detector / LDO Regulator | | **Output Voltage** | 4.0V (indicated by the '40' in 8140) | | **Package Type** | SOT-25 / SOT-23-5 (indicated by 'AF5') | | **Accuracy** | ±2.0% | | **RoHS Status** | Halogen Free / Lead-Free (indicated by 'R') | | **Operating Current** | Ultra-low power consumption (typically < 1μA) | --- ### 2. Part Number Breakdown Understanding the nomenclature helps in identifying replacements or equivalents: * **81**: Series identifier (Voltage Detector/Regulator series). * **40**: Output/Detection Voltage (4.0 Volts). * **AF5**: Package code for **SOT-25** (also known as SOT-23-5). * **D**: Standard functional grade (often relates to delay time or output type). * **R**: Tape & Reel packaging (RoHS compliant). --- ### 3. Pin Configuration (SOT-25) For the 81 series in a 5-pin package, the pinout generally follows this standard: | Pin Number | Name | Function | | :--- | :--- | :--- | | 1 | **OUT** | Output Signal (Reset or Regulated Voltage) | | 2 | **VDD** | Input Power Supply | | 3 | **VSS** | Ground | | 4 | **NC / CD** | No Connection or External Delay Capacitor | | 5 | **NC** | No Connection | --- ### 4. Key Applications This component is designed for power management in battery-operated devices where energy efficiency is critical. * **Microprocessor Reset:** Ensuring the CPU starts only when the voltage is stable. * **Battery Life Monitoring:** Triggering a "low battery" signal when the voltage drops below 4.0V. * **Power Failure Detection:** Protecting memory or circuits during sudden power loss. --- ### 5. Equivalent/Alternative Parts If this UTC part is unavailable, engineers often look at these similar series: * **Seiko/ABLIC:** S-80840 Series * **Torex:** XC61C Series * **Holtek:** HT7040 Series ---