By integrating its sub-GHz RF and low-frequency technologies, Melexis has developed a RF IC optimised for use in vehicle activation, logistics and various Internet of Things (IoT) applications such as: passive keyless entry & start (PKES), secure access and low-power tracking systems.
The IC’s 3DLF interface features an automatic and fully programmable scan mode, constantly polling for a valid low frequency (LF) signal on the 3 differential receive coil inputs. This allows for a typical 4uA power consumption in LF detection mode. The LF-RSSI feature allows precise monitoring of the received LF field. Working in combination with the system’s host microcontroller, it can run in passive transponder mode and thereby support battery-less operation.
The device has been optimised for use in the sub-GHz ISM bands, covering 300MHz to 960MHz, and delivers a transmitter output of -20dBm to +13dBm. It has a receiver sensitivity down to -120dBm in a 15kHz channel bandwidth. A 250kbps maximum data rate is supported.
Modulation schemes that can be used are on-off keying (OOK), binary frequency shift keying (FSK), minimum shift keying (MSK), Gaussian minimum shift keying (GMSK) and Gaussian frequency shift keying (GFSK).
According to the company engineers will be able to program the MLX73290-A through its serial peripheral interface (SPI) -a number of different parameters are adjustable such as: RF output power, RF bandwidth, modulation type, LF polling mode, LF/RF packet handlers, etc.
Evaluation boards and software tools are available to accompany this IC, making it easier to deploy.
When combined with the MLX74190 high power initiator device, the MLX73290-M sub-GHz ISM transceiver and an MLX81109 LIN slave interface, the MLX73290-A becomes part of a highly effective passive start solution for 2-wheelers (such as motorcycles, scooters, etc.), all-terrain vehicles and secure door entry systems.
Melexis’ MLX73290-A devices are supplied in 5mm x 5mm 32-lead QFN packages, covering an operational temperature range from -40°C to 105°C.
