Atmel Corp., a developer of semiconductors, announced availability of its new laser diode driver chip for use in combined Blu-ray/HD DVD, DVD, CD players and optical disc drives for personal computers. The chip may enable combined Blu-ray/HD DVD drives, however, it still requires a number of different lasers for different types of discs.
Up to now, a cost-efficient Blu-ray/HD DVD/DVD/CD system required the use of four devices: three oscillator chips and one transimpedance amplifier, whereas Atmel’s new ATR0885 makes it possible “to build an extremely cost-efficient blue laser system with only one chip”. While several makers have announced combined Blu-ray/HD DVD players, it is unclear how they are designed.
Atmel’s ATR0885 chip contains three outputs, each of which can be used for either the connection of blue laser diodes with a wavelength of 405 nm (Blu-ray/HD DVD), DVD laser diodes with a wavelength of 780 nm, or CD laser diodes with 650nm. Blue laser diodes used for HD- Blu-ray/HD DVD systems need a voltage source which is capable of handling higher voltages than the 5V commonly used for DVD and CD laser diodes. To meet this demand, each of the ATR0885’s three outputs has a separate voltage supply pin providing up to 8V.
The developer claims that competing products only have outputs predetermined for the blue laser functionality, whereas the ATR0885 lets the system designer freely select which of the three outputs shall be dedicated to blue laser functionality. This means the designer can chose the output optimally located in a specific design so that the connection lines are as short as possible, which allows the creation of designs which are smaller and more cost-efficient while providing high performance, according to Atmel.
The San Jose, California-based chip designer explained that for automatic power control, a transimpedance amplifier is integrated and supports all three output channels. The gain of each channel can be set separately by using three individual resistors. An integrated oscillator reduces laser mode hopping. Using one external resistor, a frequency range from 200 to 500 MHz can be set for all outputs. Three additional resistors allow a swing of up to 100 mA (peak-to-peak) for each output separately. The oscillator can optionally be set in a spread-spectrum mode to reduce electro-magnetic interferences, Atmel indicated.
Samples of the ATR0885 are available now in small QFN24 packages. Pricing starts at $2.6 in quantities of 10 000 units.
Blu-ray and HD DVD formats compete for replacing the DVD standard. HD DVD discs can store up to 15GB on a single layer and up to 30GB on two layers. Its competitor, Blu-ray, can store up to 27GB per single layer and up to 50GB on two layers, but Blu-ray discs are more expensive to produce. The HD DVD is pushed aggressively by Toshiba and NEC as well as being standardized at the DVD Forum, which represents over 230 consumer electronics, information technology, and content companies worldwide. Blu-ray is backed by Sony and Panasonic, which are among the world’s largest makers of electronics. Among