Jun 25, 2019 - CML Enables Greater Robustness against Security Breaches with Frequency Inversion Audio Scrambler Supporting Full Duplex Operation
Recognising the growing need to protect communication systems from the threat of being compromised by unauthorised parties, CML Microcircuits has introduced the CMX7158. Based on the company’s proprietary FirmASIC® technology, this compact user-programmable scrambler IC is optimised for inclusion in multi-function audio systems, as well as handheld wireless/cellular equipment.
Maintaining elevated levels of audio quality, it can rapidly switch between clear and scrambled voice modes via a programmable frequency inversion point, with minimal delay being experienced. Furthermore, its completely independent Tx and Rx signal paths mean that this IC is capable of full duplex operation.
Thanks to FirmASIC, a Function Image™ is generated in which the CMX7158’s functional parameters are defined. This is loaded to the system upon power-up/device initialisation – either from the system’s host microcontroller (across an SPI compatible interface) or through an attached serial flash memory. Dual-tone multi-frequency (DTMF) encode/decode, Selcall signalling and VOX detection on both channels are among the other main features encompassed.
Key applications for the CMX7158 include cellular radio voice scrambling accessories. Bluetooth headsets, wired/wireless access control systems, plus private and land mobile radio (PMR/LMR), as well as legacy wireline telephony. Supplied in a space-saving 48-pin VQFN package, it supports low power operation (drawing from a 3.0V-3.6V source, with power saving modes available). The device features numerous analogue audio interfaces makking integration into existing system designs very straightforward. To assist engineers during the development process, CML offers the PE0402 evaluation board to accompany the CMX7158.