It appears to the author, that the high speed data communications sector of the market is growing fast. At least this is the conclusion that we must draw from the demands on our design resources from various customers.
USB3, 10G, HDMI, etc are all very demanding in terms of the semiconductor processes to be used ( cost effectively ), design techniques, systems engineering, CAD tools, availability of parameterics of cables, connectors, PCB based information and ultimately design techniques to stitch all of these together into a device or subsystem that will actually work in the real world.
As we work through these designs, we find that there is a vast gap between theory and reality. This includes simulations also. This has always been true in some degree with other technologies but in the case of these designs it becomes critical. Designing the devices to operate robustly in the real world is very time consuming and in many ways an art, rather than a science. Design experience is called for more than anything to implement these techniques from an intuitive point of view. We believe this is going to be a most interesting and challenging series of designs. More as the work proceeds.
The frequency 32, 768 Hz, is one of the most popular frequencies for crystal oscillators as it is used in most time keeping applications. With the proper interface circuit ( PLLs ) it can also be used for high frequency synthesizers. The actual quartz is also relatively inexpensive and this lends itself to cost effective frequency circuits and timekeeping. Of course temperature control can aso be used to generate TCXOs.
In any case, we recently designed, fabricated and throroughly analyzed a low power crystal oscillator ( in conjunction with our sister company). The circuit was first pass functional. The crystal oscillator section dissipates a mere 200 – 500 nA of current at the rated frequency.
The entire chip consists of a crystal oscillator, a low power analog buffer, a level converter and a digital output buffer capable of driving 100 pF. In addition the device has a means of trimming the frequency using an analog trim as well as a digital fine trim.
The device was evaluated thoroughly and its temperature characteristics measured extensively. Interested parties may contact us through our website at www.signalpro.biz for our experience and these results. All in all a most satisfying experience!
A first pass success is always welcome. When the sucess is a high frequency device it is doubly so. The latest addition to the high frequency, silicon proven ASSP portfolio, is a high frequency, wideband amplifer fabricated in a 0.35um SiGe process.
It is fairly general purpose and can be used as gain block, an LNA etc. The basic features are as follows:
Usable frequency gain = 100 to > 2500 Mhz
19 dB typical ac gain at 900 Mhz, VCC = 2.7V
NFMIN = 1.2 dB at 900 Mhz
NFMIN = 1.5 dB at 2500 Mhz
1 dB compression point at 900 Mz = 2.9 dBm
1 dB compression point at 2500 Mz = 0.9 dBm
OIP3 at 1.5 Ghz = 15.0 dBm
OIP3 at 2.5 Ghz = 10.0 dBm
Power supply from 2.7 to 5.0 Volt
Power supply current typical = 4.7 mA
Reverse isolation s12 = -48.0 dB min.
The device was tested from -55 Degrees C to 125 Degrees C. An extended frequency test was also done at 5.0 Ghz. The gain dropped to 17 dB. Other parameters were also slightly affected.
Anyone with interest in this device and its development may contact the author via the website located at www.signalpro.biz.