Photo Detector ICs Made Easy with X-FAB
X-FAB is the first foundry to offer a ready-to-use PDIC IP for data storage. With the highest ever reported sensitivity for 408 nm, X-FAB offers a ready-to-use solution for its fabless customers. We are providing support for multiple wavelengths being used in products such as CD, DVD and Blu-ray drives. The provided IP blocks are optimized to support different product generations.
Photo Detector IC - Block Diagram
Photo Detector IC (PDIC) for Data Storage
The PDIC is part of the optical pick up unit of CD, DVD and Blu-ray data storage drives. It detects the signals reflected from the disk surface. The signals are amplified available at the outputs of the PDIC.
Double layer media, fast rotating speed generate high requirements for the signal detection and the amplification. Weak signals need a good combination of high sensitive photo diodes and high gain low noise trans impedance amplifiers (TIA) to get a high signal to noise ratio. Temperature dependency has to be very low.
Reading and writing at different speeds give different signals back. The support of several gains is necessary for the TIA. In case of supporting combined three wavelength systems for Blu-ray, DVD and CD a good sensitivity for blue light 405nm, red light 650nm for DVD and infrared light at 780nm for CD is necessary.
Photo diodes have to be high sensitive and need a high bandwidth to support up to12x Blue-ray speed. In addition to the new Blu-ray standard which uses a wavelength of 405nm the legacy DVD (650nm) and CD (780nm) have to be supported too.
Highly sensitive PIN diodes are available as characterized devices in the technologies XB06 and XO035.
The PIN diodes dpinb in XB06 and XO035 are optimized for blue light and can be used for single Blu-ray PDIC or combined Blu-ray/DVD/CD sensors.
- Highest sensitivity for blue light (0.3A/W @ 405nm)
- High sensitivity at 650nm and 780nm
- High bandwidth
- Low dark current
TIA – Trans Impedance Amplifier
A selection of low noise, high frequency bipolar (XB06) and CMOS transistors can be used to design trans impedance amplifiers supporting high bandwidth, high signal to noise ratios and low temperature dependencies.
Analog-to-Digital Converter (ADC)
Depending on requirements Analog Digital Converters can be designed by using the standard core or additional modules for reduced noise, trimming devices or memory.
The use of junction isolated devices makes the ADC design robust versus substrate noise. Zener zaps and fuses are available for trimming of parameters like offset during wafer probing or final test. Several robust ADCs (SAR until 10Bit) can be selected from X-FABs analog standard cell library.
Different digital libraries optimized for speed, low power, low noise and low threshold are available for all of X-FAB's process technologies allowing optimized designs. For low noise/low leakage applications special junction isolated digital libraries can be used. To store firmware for controller or other data a portfolio of non-volatile memories can be used. Unique to X-FAB is the possibility to use EEPROM and FLASH on the same chip. Hard- and software co-design allows fast, reliable and flexible creation of memory cells.
There are I/O libraries for core or pad limited designs available. For applications that require a high ESD protection special high ESD resistance I/O libraries can be selected. RF I/Os supporting different metal layers allow flexible designs. Special high-voltage I/Os are also selectable.