Wireless control receivers
Neubiberg, Germany: Infineon Technologies has developed three wireless control receivers that are designed to provide high sensitivity and low power consumption. The TDA5240, TDA5235, and TDA5225 provide multi-band support (315, 434, 868, and 915 MHz) for global coverage.
These devices suit various automotive applications, including remote keyless entry (RKE) systems, tyre pressure monitoring systems (TPMSs), remote start, control, status, and alarm functions. The receivers also can take over some of the tasks that are typically performed by the system’s microcontroller.
The TDA5240, TDA5235, and TDA5325 are successors to the TDA5230/31 receiver family. Functionalities like IF filter and level shifters are now integrated. An integrated low-noise amplifier (LNA) can extend the system range or eliminate the need for an external LNA to reduce system complexity and costs.
The family’s high sensitivity, typically –119 dBm for frequency shift keying (FSK) and–116 dBm for amplitude shift keying (ASK), is due to a reduced noise figure and noise bandwidth using improved digital signal processing.
Compared to Infineon’s current receiver products, which offer an average data rate of 40 kchips/s, the TDA5240/35/25 devices provide a data rate with several embedded encodings and modulation schemes specified at up to 112 kchips/s (FSK).
System designers can use the multi-band, multi-channel receivers for systems operating at the 315/434/868/915-MHz frequency bands, with one crystal for all supported frequency bands.
A high-resolution sigma-delta fractional-N phase-locked loop (PLL) synthesizer provides a fine multi-channel resolution of 10.5 Hz. Multi-protocol handling enables flexible designs based on one platform. The receivers can handle data from both RKE and TPMS transmitters.