Three IC Makers Rise To Multiple Mobile-Display Lighting Challenges

Lighting in handheld portable devices continues to encourage innovation. For medium-size panels with cold-cathode fluorescent-tube backlights, Fairchild Semicon-ductor's FAN7310 full-bridge pulse-width modulation inverter/driver IC supports multiple operating modes using phase-shift control. Designers can choose either zero-voltage or zero-current switching. It operates from 5 to 24 V. The 20-lead SSOP is sampling, and 1k-pricing is $2.75.

On a different scale, Microsemi's LX1995 is a dual-use backlight/flash driver for cell-phone-size displays. Typically, it powers six white LED backlights. But if a separate white LED array is used for flash photography, it will drive the flash array while momentarily dimming the display. It comes in a five-lead TSOT for $0.58, or SOT-23 for $0.50, both in 10k quantities.

Linear Technology's LTC3206 step-up/step-down, fractional charge-pump voltage converter (see photo) can drive a six-LED main display, a four-LED subdisplay, and RGB party lights. Efficiencies reach 92% with quiescent current of 180 µA. Dimming and on/off control for all displays is achieved via I2C. Unit-pricing starts at $2.20 for 1k quantities.