Frequency Agile RF Receiver Chip for AMR and Remote Controls

Melexis launches the MLX71122, the frequency agile version of a first new highly integrated RF receiver family. This multi channel receiver IC has been designed for applications in the unlicensed Industrial-Scientific-Medical (ISM) and Short-Range-Devices (SRD) frequency bands at 300 to 930 MHz.

All multi-channel, multi-band and frequency-agile low-power RF systems benefit from the receiver’s programmable PLL. This enables addressing all sub-bands of the European 863 - 870MHz band just by software. Even large frequency jumps across regionally different bands like the US 315MHz or 915MHz as well as the European 433MHz are possible without changing the RF hardware. Manufacturers of world-wide equipment for Automatic Meter Reading (AMR) and RF remote controls benefit through the simplification of their production logistics and the indirect reduction in cost.

The small 32 lead QFN package with a footprint of 5mm x 5mm and the fact that no bulky external ceramic filter and discriminator components are needed make the MLX71122 the optimum choice for systems asking for smallest feature size and lowest cost.

The MLX71122 accepts supply voltages from 3V to 5.5V with a typical current consumption of 11mA. In standby mode the current draw is below 50nA. The receiver input sensitivity is as low as -112dBm for ASK and -107dBm for FSK signals, respectively.

The MLX71122 combines flexibility with high levels of circuit complexity. It dramatically reduces system cost thanks to the internal IF filter and FSK/ASK demodulators. The receiver’s AFC feature can tolerate frequency uncertainties of the input signal.

Dr. Andreas Laute, Manager of Melexis’ Business Unit Wireless Communication, states: “After last year’s introduction of the new highly integrated fixed-frequency receiver ICs, MLX71120 and MLX71121, this frequency agile receiver is a new step that confirms our commitment to increase performance while decreasing size and cost for our customers.”

The extended operating temperature range of -40 to +105 °C makes the MLX71122 ideally fit for AMR and RF remote control applications in harsh environments. Other typical applications for this receiver IC include automotive remote keyless entry (RKE), tire pressure monitoring systems (TPMS), security systems, home automation, garage door openers, wireless door bells, baby monitors and wireless headsets.