Date: 05/08/2010

Semtech and Microchip's combined reference design for wireless remote keyless entry

Semtech and Microchip have made available reference design that provides a turnkey platform for secure, low-power, multi-band wireless remote keyless entry (RKE) systems for automotives, home and office buildings. This new reference design integrates Semtech's high-performance transmitter and transceiver ICs with Microchip's KEELOQ code-hopping technology running on PIC microcontrollers (MCUs). It is designed to simplify to work across major frequency regulations complying with major country-specific radio regulations .

In this reference design, the Tx board pairs Semtech's SX1230 industrial, scientific and medical (ISM) band transmitter with Microchip's PIC16F631 or PIC16F677 8-bit microcontrollers. The Rx board employs Semtech's SX1211 or SX1212 ISM transceivers, again with Microchip's PIC16F631 or PIC16F677 microcontrollers.

The SX1230 is configurable and dynamically programmable for narrowband and wideband applications in the 315, 434, 868 and 915 MHz license-free ISM frequency bands, and works with FSK, GFSK, MSK, GMSK and OOK modulation formats up to 600 kb/s, with constant RF performance over the 1.8V to 3.7V operating range. SX1230 consumes 30 mA current at +10dBm output power and 500 nA sleep mode current to enhance the battery life. RF output power is programmable up to +17 dBm in 1 dB steps from -20 dBm.

Microchip says KEELOQ security algorithm encrypts information in the RF transmission packets before they are transmitted, unlike some existing RKE systems in the market. This ref. Design stores confidential information inside the Flash memory of the PIC microcontroller and then encrypts it inside each data packet, prior to any RF transmission.

"Our relationship with Microchip means we can now provide a highly secure, turnkey RKE reference solution integrating the industry's highest performing microcontrollers and RF ICs, along with leading security encryption software," said Sameer Vuyyuru, Semtech Vice President Marketing for Semtech's Advanced Communications and Sensing Group. "RKE designers now have a reference solution that does not require specialized RF design or encryption programming skills, compared to discrete or analog RF integrated circuit approaches that require security software and RF engineering expertise, and involve long design cycles with extensive production stabilization efforts."

"This new RKE reference platform offers a strategic combination of security along with high-performance, low-power processing and RF transmission," said Vivien Delport, director of Applications for Microchip's Security, Microcontroller & Technology Development Division. "Semtech brings the high-performance transmitters and receivers that, when integrated with our KEELOQ code-hopping technology and PIC microcontrollers, results in RKE systems that are easy to design, secure, low power, cost effective and easily adaptable to multiple global standards."