AD9660

The AD9660 is a highly integrated driver for laser diode applications such as optical disk drives, printers, and copiers. The AD9660 gets feedback from an external photo detector and includes two analog feedback loops to allow users to set "bias" and "write" (for optical disk drives) power levels of the laser, and switch between the two power levels at up to 200 MHz. Output rise and fall times are typically 1.5 ns and 2.0 ns to complement printer applications that use image enhancing techniques such as pulse width modulation to achieve gray scale, and allow disk drive applications to improve density and take advantage of pulsed write formats. Control signals are TTL/ CMOS compatible.

The driver output provides up to 180 mA of current @ 3 V, 90 mA of BIAS current, 60 mA of modulation current, and 30 mA of offset current. The onboard disable circuit turns off the output drivers and returns the light power control loops to a safe state.

The AD9660 can also be used in closed loop applications in which the output power level follows an analog WRITE LEVEL voltage input. By optimizing the external hold capacitor, and the photo detector, the write loop can achieve bandwidths as high as 25 MHz.

The AD9660 is offered in a 28-pin plastic SOIC for operation over the commercial temperature range (0°C to +70°C).