TP8556N

TP8556N is a buck LED constant-current driver operating in fixed off-time control mode, designed for efficiently driving multiple LEDs. TP8556N employs an average-current closed-loop constant-current scheme, making the output current insensitive to inductance variations in system applications. This greatly improves the constant-current accuracy of the output current, making it particularly suitable for non-isolated buck LED constant-current driver circuits with an input voltage range of 5~100V. TP8556N uses an external power transistor, and the average LED output current can be set via an external resistor. High/low brightness mode switching of the LED output can be achieved by applying high or low logic levels to the MODE pin. When the MODE pin is pulled high, the LED output operates in 50% low-brightness mode; when the MODE pin is pulled low, the LED output operates in 100% high-brightness mode. This requires very few external components to implement LED high/low brightness mode switching, reducing system cost and board space.

Applications

• Automotive lighting
• E-bike lighting
• High-power flashlight LED backlight driving

Key features

• Wide system input voltage range: 5~100V
• Fixed off-time control mode
• Average current closed-loop constant current control
• ±5% LED output current accuracy
• LED high/low brightness output mode
• Insensitive to inductance variations
• High system operating efficiency
• Integrated analog dimming function
• Built-in 5.6V VDD Zener diode
• LED output short-circuit protection
• Intelligent chip temperature control
• SOT23-6L package