This application note introduces ambient light sensing on a general level. The different types of ambient light sensors are described and related to specific applications. The part **SFH 5711** is manufactured by **OSRAM Opto Semiconductors**. Below are its specifications, descriptions, and features based on factual information from Ic-phoenix technical data files:  

### **Specifications:**  
- **Type:** Silicon NPN Phototransistor  
- **Package:** Surface-mount device (SMD)  
- **Wavelength Range:** 400 nm to 1100 nm (peak sensitivity at 850 nm)  
- **Collector-Emitter Voltage (V_CEO):** 30 V  
- **Emitter-Collector Voltage (V_ECO):** 5 V  
- **Collector Current (I_C):** 20 mA  
- **Power Dissipation (P_tot):** 75 mW  
- **Operating Temperature Range:** -40°C to +85°C  
- **Storage Temperature Range:** -40°C to +100°C  

### **Description:**  
The **SFH 5711** is a high-sensitivity **NPN silicon phototransistor** designed for applications requiring fast response and high reliability. It is optimized for **infrared (IR) detection** with peak sensitivity at **850 nm**, making it suitable for **remote control systems, light barriers, and optical sensors**.  

### **Features:**  
- **High sensitivity** in the near-infrared range  
- **Low dark current** for improved signal-to-noise ratio  
- **Compact SMD package** for space-constrained applications  
- **Fast switching times** for responsive detection  
- **RoHS compliant**  

This information is based on OSRAM's official documentation for the **SFH 5711** phototransistor.

This application note introduces ambient light sensing on a general level. The different types of ambient light sensors are described and related to specific applications.