LED backlight boost switches reduce power losses, minimize sub-harmonic oscillation in high-power LED applications

October 02, 2012 // By Paul Buckley
Fairchild Semiconductor’s FAN7340 and FAN73402 single-channel boost controllers with integrated high-voltage dimming MOSFETs aim to help designers achieve greater efficiency, performance and better reliability in high-power lighting applications such as LED backlighting for 3D televisions and monitors.

The backlight driving boost switches use a current-mode control topology with programmable slope compensation to prevent sub-harmonic oscillation. Designed with an internal dimming and analog pulse-width modulation (PWM), these devices overcome the short falls of a DCM boost converter by achieving a fast PWM dimming response.

Both devices offer integrated protection features such as under-voltage lockout, open LED protection, and over-voltage protection that help to minimize component count. Additionally, these devices provide error prevention by generating a FAULT signal with delay if an abnormal LED string condition occurs.

Availability and Pricing

The FAN7340 and FAN73402 single-channel boost controllers are available in a 16-lead SOIC package the FAN7340 is priced at $0.85 and the FAN73402 is priced at $1.06 1,000 quantity pieces.

For more information about the FAN7340 and FAN73402 single-channel boost controllers at