Micronas Introduces First All CMOS Intermediate Frequency (IF) Chip to Handle Analog and Digital Broadcast Signals (0020)
Freiburg 21 November 2000 - Micronas introduced at Electronica the first all CMOS integrated circuit (IC) for the entire demodulation of the IF signal used in TV sets. In addition to the new DRX chip, only one simple and cost efficient surface acoustic wave (SAW) filter is required. The DRX provides the initial technology enabling TV sets to receive digitally broadcasted programs.
Previous circuits for the demodulation of IF signals have been analog, requiring multiple additional external filters, mainly expensive SAWs. This has had complex production implications for television manufacturers since many countries have different TV standards requiring different types of analog circuits which in turn require different types of SAW filters. Micronas' DSP-based DRX is optimized for every different standard by using an adjustable filter. This filter compensates for changes in frequency response occurring during signal processing, where an equalizer is used to correct changes in the phase of the signal.
"By using only one single IF filter instead of adding several external SAWs, the DRX offers considerable cost benefits," said Hans Fiesel, senior concept engineer at Micronas. "At the same time we have been able to deliver a higher performance chip using the DSP element to perform standard dependent filtering internally."
One of the most important features of the DRX is its ability to receive both analog and digital broadcast programs. In addition, while receiving TV signals, the DRX demodulator also offers FM signal reception, removing the need for additional complex analog circuitry. The DRX also offers superior performance by using automatic frequency control (AFC). This type of accurate fine tuning has proven extremely difficult to perform using analog technology.
The device's viewing quality is enhanced by the use of digital signal processing and is relatively insensitive to signals out of tune. It does not suffer from any picture quality loss if the deviation is within a few hundred kilohertz. Since the DRX needs the type of SAW that is required for receiving digital programs, it paves the way to digital TV in the future. Because of the integrated DSP it is no problem to also add digital demodulation, which is not included in the current version of the DRX. Micronas will offer the DRX with digital demodulation by 2002. The current version of the DRX offers manufacturers the opportunity to take the first steps towards the development of TVs that can receive both analog and digital programs.
The DRX is available in sample quantities and comes in a 44-pin Quad Flat Packages. The price for the DRX will be below 4 US Dollars.