LED Driver Offers 10% Higher Efficiency and Easy Interface Control for Portable Device Backlighting

The CAT3637 is optimized for applications with one bank of five or six identical LED channels, a typical configuration for larger LED screen portable products. The device incorporates a simplified version of Catalyst’s already easy-to-use, 1-wire EZDim interface, which supports 16 output power levels, from from zero to 30mA full brightness 2mA resolution steps. With efficiency levels as high as 92 percent, no added capacitors required, and a tiny 3 x 3mm, low-profile TQFN package, the Quad-Mode CAT3637 saves significant board space and costs in next-generation portable products.

According to Scott Brown, Vice President of Marketing for Catalyst Semiconductor, “When it comes to LED-based products, we are seeing a wide variety of design approaches throughout the market, depending on the customer and application. The CAT3637 is the fifth device in Catalyst’s Quad-Mode product line and exemplifies our strategy to be a “one-stop” vendor for a broad range of LED drivers which address this diversity of customer requirements.”

The CAT3637 joins the following devices in Catalyst’s Quad-Mode family of LED drivers: the CAT3604V four-channel LED driver with PWM dimming interface; and the CAT3636 six-channel, CAT3644 four-channel and CAT3643 three-channel devices with 1-wire EZDim™ interface.

The CAT3637 LED driver is priced at $0.82 each in 10,000 piece quantities. Samples and evaluation boards are also available. Projected lead-time for production quantities is currently 6 to 8 weeks ARO.

Catalyst’s patented Quad-Mode adaptive fractional charge pumps take LED driver performance to a new level by offering a 10 percent efficiency improvement, without the need for an additional capacitor, and with no price premium. The Quad-Mode switching architecture delivers efficiency levels as high as 92 percent, with a lifetime average efficiency of 84 percent, yet saves significant board space and costs.

Catalyst’s innovative, patented Quad-Mode charge pump architecture delivers the high efficiency levels normally associated with inductor-based LED drivers, while eliminating the associated high-profile inductors and unwanted EMI. Most charge pump LED drivers today offer three modes of operation corresponding to the ratio of the output voltage to the input voltage: 1x, 1.5x and 2x. The Quad-Mode architecture adds a fourth mode of operation, 1.33x, without the need for the additional capacitor required by all existing four-mode charge pumps. The 1.33x fractional operating mode also reduces the input switching currents seen at the battery, minimizing the overall supply noise – a critical parameter in portable devices.