Atmel's ATR0881 laser-diode-driver IC, targeted at combined HD-DVD/Blu-ray, DVD, and CD drives, comes in a 4mm by 4mm QFN24 package. It's especially suited for small slim drives used in notebook computers, as well as for half-height drives in desktop PCs and consumer DVD recorders, says the company.
The QFN housing is a lead-free paddle-up package, with the exposed paddle on top to improve heat dissipation. A bottom-located exposed paddle, as found in conventional QFN packages, causes difficulties due to its inaccessibility for circuit design, particularly in optical pick-up products.
Although the ATR0881 has three outputs for connecting three laser diodes—a blue (HD-DVD/Blu-ray), a red (DVD), and an infrared (CD)—it still fits into the same small 24-pin package used by the company's laser diode drivers for two-output combined DVD and CD drives.
The ATR0881 comes with a serial interface. Whereas conventional laser diode drivers have a fixed gain between input and output, the gain of each of the ATR0881's five channels can be individually programmed using the serial interface. As a result, the chip is extremely flexible and avoids complete re-designs if the users’ gain requirements change.