FAN5346: Series Boost LED Driver with PWM Dimming Interface

The FAN5346 is an asynchronous constant-current LED driver that drives LEDs in series to ensure equal brightness for all the LEDs. FAN5346S20X has an output voltage of 20V and can drive up to 5 LEDs in series. FAN5346S30X has an output voltage of 30V and up to 8 LEDs in series. Optimized for small form-factor applications, the 1.2MHz fixed switching frequency allows the use of small inductors and capacitors.

The FAN5346 uses a PWM dimming control interface to set the brightness levels of the LEDs. A PWM signal of 5kHz to 100kHz is applied to the EN pin.

For safety, the device features integrated over-voltage, over-current, short-circuit detection, and thermal-shutdown protections. In addition, input under-voltage lockout protection is triggered if the battery voltage is too low.

The FAN5346 is available in a 6-lead SSOT23 package. It is “green” and RoHS compliant.

Features

• Asynchronous Boost Converter
• Drives LEDs in Series:
  • FAN5346S20X: 20V Output
  • FAN5346S30X: 30V Output
• FAN5346S20X: 20V Output
• FAN5346S30X: 30V Output
• 2.5V to 5.5V Input Voltage Range
• PWM Dinning for LED Brightness Control
• 5kHz to 100kHz PWM Dimming Frequency Range
• 1.2MHz Fixed Switching Frequency
• Soft-Start Capability
• Input Under-Voltage Lockout (UVLO)
• Output Over-Voltage Protection (OVP)
• Short-Circuit Detection
• Thermal Shutdown (TSD) Protection
• Small Form-Factor 6-Lead SSOT23 Package

Application Notes