## AS1361 Electronic Component Overview The **AS1361** is a high-performance, low-dropout (LDO) linear voltage regulator designed specifically for battery-powered devices. It is manufactured by **ams OSRAM** and is known for its exceptionally low noise and high Power Supply Rejection Ratio (PSRR). --- ### 1. Key Technical Specifications The AS1361 is optimized for low power consumption and signal integrity in sensitive RF and analog circuits. | Feature | Specification | | :--- | :--- | | **Input Voltage Range** | 2.0V to 5.5V | | **Output Voltage** | Fixed (1.2V to 4.5V) or Adjustable | | **Output Current** | Up to 150mA | | **Dropout Voltage** | ~100mV @ 150mA load | | **Quiescent Current** | 40µA (Typical) | | **Shutdown Current** | < 1µA | | **PSRR** | 92dB @ 1kHz / 70dB @ 10kHz | | **Package** | 5-bump WLCSP or 6-pin SOT23 | --- ### 2. Core Functional Features * **Ultra-Low Noise:** The internal architecture is designed to minimize thermal and flicker noise, making it ideal for powering VCOs, PLLs, and high-end audio DACs. * **Stability with Ceramic Capacitors:** Unlike older LDOs that require high ESR tantalum capacitors, the AS1361 is stable with small, low-cost ceramic capacitors (minimum 1µF). * **Safety Protections:** * **Thermal Overload Protection:** Shuts down the device if the junction temperature exceeds safety limits. * **Short-Circuit Protection:** Limits current to prevent damage during a fault. * **Enable Pin (EN):** A digital input that allows the chip to be turned on or off to conserve battery life in handheld electronics. --- ### 3. Pin Configuration (Typical SOT23-5) Below is the standard pinout for the AS1361 series: | Pin Number | Name | Description | | :--- | :--- | :--- | | 1 | **VIN** | Unregulated Input Supply | | 2 | **GND** | Ground | | 3 | **EN** | Logic High = On; Logic Low = Off | | 4 | **BP/ADJ** | Bypass Capacitor (Fixed version) or Feedback (ADJ version) | | 5 | **VOUT** | Regulated Output Voltage | --- ### 4. Typical Application Circuit The AS1361 requires minimal external components to function correctly: ```text [VIN] ----+-----------[ AS1361 ]-----------+---- [VOUT] | (LDO REG) | [C_in] [C_out] | [ C_bp ] | [GND] ----+----------------+---------------+---- [GND] ``` * **C_in:** 1µF Ceramic. * **C_out:** 1µF Ceramic (essential for stability). * **C_bp:** 10nF (optional for additional noise reduction). --- ### 5. Common Use Cases 1. **Mobile Phones:** Powering sensitive radio frequency (RF) stages. 2. **Medical Equipment:** Low-noise power for handheld diagnostic sensors. 3. **GPS Receivers:** Providing clean power to satellite signal processors. 4. **Wireless LAN:** Stable voltage regulation for WiFi modules.