Current Regulated Switched Capacitor LED Supply with Analog and PWM Brightness Control The LM2794BL is a charge pump-based white LED driver manufactured by National Semiconductor (NS).  

### **Specifications:**  
- **Input Voltage Range:** 2.7V to 5.5V  
- **Output Current:** Up to 32mA per LED (4 LEDs total)  
- **Efficiency:** Up to 90%  
- **Switching Frequency:** 1MHz (typical)  
- **Operating Temperature Range:** -40°C to +85°C  
- **Package:** 10-pin LLP (Leadless Leadframe Package)  

### **Descriptions and Features:**  
- **Charge Pump Architecture:** Uses a 1x/1.5x/2x fractional charge pump for efficient power conversion.  
- **Independent LED Current Control:** Each of the four LED channels can be controlled individually.  
- **PWM Dimming Support:** Allows brightness control via pulse-width modulation (PWM).  
- **Low Noise Operation:** Minimizes EMI interference.  
- **Thermal Protection:** Includes built-in thermal shutdown to prevent overheating.  
- **Small Footprint:** Suitable for space-constrained applications like mobile devices.  

The LM2794BL is designed for driving white LEDs in portable electronics, such as backlighting for LCD displays.

Current Regulated Switched Capacitor LED Supply with Analog and PWM Brightness Control

Current Regulated Switched Capacitor LED Supply with Analog and PWM Brightness Control The LM2794BL is a charge pump-based LED driver manufactured by National Semiconductor (NSC). Below are its specifications, descriptions, and features:

### **Specifications:**  
- **Input Voltage Range:** 2.7V to 5.5V  
- **Output Current:** Up to 32mA per channel (adjustable)  
- **Number of Channels:** 3  
- **Switching Frequency:** ~1MHz  
- **Efficiency:** Up to 90%  
- **Package:** 10-pin LLP (Leadless Leadframe Package)  
- **Operating Temperature Range:** -40°C to +85°C  

### **Descriptions:**  
The LM2794BL is a high-efficiency, fixed-frequency charge pump designed to drive up to three white LEDs with constant current. It eliminates the need for external inductors, making it suitable for space-constrained applications. The device includes an internal current regulator for uniform brightness across LEDs.  

### **Features:**  
- No external inductors required  
- Adjustable output current via external resistor  
- Low dropout operation  
- Soft-start feature to limit inrush current  
- Thermal shutdown protection  
- Low quiescent current in shutdown mode (<1µA)  
- Compatible with PWM dimming  

The LM2794BL is commonly used in portable electronics, such as mobile phones, PDAs, and handheld devices, for backlighting applications.

Current Regulated Switched Capacitor LED Supply with Analog and PWM Brightness Control