MUNICH -- As an alternative to discrete surface acoustic wave (SAW)-based systems for short-range transceiver systems, Infineon Technologies AG today announced a crystal-controlled RF transmitter and receiver chip set that combines a high level of integration, universal applicability, high efficiency and value pricing, the company claimed.
Standard short-range devices, the TDA 5100 transmitter and TDA 5200 receiver, are available for both the European frequency bands of 868-870 MHz and 433-435 MHz. For the United States, Infineon offers the TDA 5101 and TDA 5201 at 315 and 345 MHz.
The RF ICs apply HF PLL (high-frequency, phase-locked loop) principles to achieve a frequency stability that is 10 times better than SAW resonators, and at a lower cost. With improved frequency stability, the design enables the implementation of high-performance receiver/transmitter solutions that are highly interference tolerant.
Targeted at low-powered remote keyless entry systems, the new chip set also has applications in the growing number of short-range, home-based radio RF applications such as security, control, and detection. Industrial applications include alarm systems and lighting control.
"To exploit new opportunities in the highly price-sensitive consumer market, manufacturers are demanding both reliable performance and low cost," said Joseph Pietrowicz, Infineon's product marketing manager for RF semiconductors in San Jose. "This target can only be achieved for simple and inexpensive radio subassemblies by designing new, higher levels of integration into ICs, allowing them to work with just a few peripheral components."
The transmitter, a single-chip amplitude shift keying/frequency shift keying (ASK/FSK) device, is crystal-controlled with an on-board filter to limit the number of external components. The TDA 5100 transmitter features a fully integrated VCO, a PLL synthesizer, a crystal oscillator with a divided clock output to drive a microcontroller, and a power amplifier to drive a loop antenna. With a supply voltage range from 2.1 to 4 volts, the TDA 5100 is suited for use with a single 3.6-V lithium-ion battery.
The receiver, the TDA 5200, is a single-chip ASK super heterodyne device that contains a low-noise amplifier and a double balanced mixer at the front end. An integrated voltage control oscillator is included on the IC to provide the local oscillator signal for the mixer.
A PLL synthesizer, a crystal oscillator, a limiter with RSSI generator, a data filter, a data comparator and a peak detector are also on the chip. Power supply is 5 V with a low supply current of 4.7 milliamps. Both the receiver and the transmitter include a power down mode that limits consumption to 50 nanoamps.
The TDA 5100 is available in a standard TSSOP-16 plastic package and the TDA 5200 is offered in a TSSOP 28-pin plastic package. In production quantities of 50,000, the TDA 5100 transmitter is listed at 85 cents each and the TDA 5200 receiver at $1.50. Sample quantities are also available on request.