CMX7158Q3 CML Microcircuits

CMX7158 Duplex Audio Scrambler Duplex Frequency Inversion Scrambler D/7158/2 October 2021 DATASHEET Provisional Information TxENA and RxENA outputs Features Flexible Powersave Modes Fully independent Tx and Rx paths Low-power 3.0 to 3.6V Operation Programmable Inversion points Small 48-pin Q3 VQFN Package MIC path AGC Applications VOX detection Cellular radio accessories DTMF encoder / decoder Bluetooth headsets Selcall encoder / decoder PMR/LMR systems Digital Gain Adjustment Wireless access control systems C-BUS Serial Interface to Host Controller Intercom systems Bypass mode for HD Audio (up to 7kHz) Wired telephony Clear Mode Tx Audio Input Tx Audio Output Rx Audio Input Rx Audio Output Tx Enable Reference Clock CMX7158 Rx Enable 3.3 to 3.6 V Duplex Audio Scrambler Built on FirmASIC Technology Tx VOX Triggered C-BUS Host Rx VOX Triggered C 1 Brief Description The CMX7158 is a full-duplex, frequency inversion audio scrambler IC. This makes it a suitable device for use in multi- function audio systems as well as mobile and hand portable Cellular / Bluetooth / PMR / LMR radio systems. The device provides additional functionality to facilitate implementation including DTMF and Selcall signalling, VOX detection on both channels and a MIC AGC. There are flexible power-saving modes and the device is available in a 48-pin VQFN Q3 package suitable for use with the PE0402 evaluation kit. TM The device is derived from CMLs proprietary FirmASIC component technology. A function image that defines the devices functionality is loaded at power up. 2021 CML Microsystems Plc Duplex Audio Scrambler CMX7158 CONTENTS Section Page 1 Brief Description .......................................................................................................................................................... 1 2 Block Diagram.............................................................................................................................................................. 5 3 Performance Specification ........................................................................................................................................... 6 Electrical Performance .......................................................................................................................................................... 6 Absolute Maximum Ratings typical figures ........................................................................................................................ 6 Operating Limits ................................................................................................................................................................... 6 Operating Characteristics ..................................................................................................................................................... 7 Parametric Performance ..................................................................................................................................................... 11 C-BUS Timing ...................................................................................................................................................................... 13 4 Pin and Signal List ...................................................................................................................................................... 14 Signal Definitions ................................................................................................................................................................ 15 5 Component and PCB Recommendations .................................................................................................................... 16 Recommended External Components ................................................................................................................................ 16 PCB Layout Guidelines and Power Supply Decoupling ....................................................................................................... 18 6 General Description ................................................................................................................................................... 19 7 Detailed Descriptions ................................................................................................................................................. 20 Xtal Frequency .................................................................................................................................................................... 20 Host Interface ..................................................................................................................................................................... 20 C-BUS Operation ................................................................................................................................................................. 20 C-BUS Timing ...................................................................................................................................................................... 21 Device Initialisation ............................................................................................................................................................. 22 Host Loading The Function Image....................................................................................................................................... 22 Device Control .................................................................................................................................................................... 24 Signal Routing ..................................................................................................................................................................... 24 Mode Control ...................................................................................................................................................................... 25 Audio Functions .................................................................................................................................................................. 25 Audio Receive Mode ........................................................................................................................................................... 25 Audio Transmit Mode ......................................................................................................................................................... 26 Selcall and DTMF ................................................................................................................................................................ 27 Transmitting Selcall and DTMF Tones ................................................................................................................................. 27 Receiving and Decoding Selcall Tones ................................................................................................................................ 27 Receiving DTMF Tones ........................................................................................................................................................ 28 Alternative Selcall Tone Sets ............................................................................................................................................... 29 Digital System Clock Generator .......................................................................................................................................... 29 Main Clock Operation ......................................................................................................................................................... 29 GPIO ............................................................................................................................................................................ 30 Signal Level Optimisation .................................................................................................................................................... 30 8 Evaluation ................................................................................................................................................................. 31 9 Packaging .................................................................................................................................................................. 32 Table Page Table 1 Definition of Power Supply and Reference Voltage .............................................................................................................. 15 Table 2 Recommended External Components (typical example) ...................................................................................................... 16 Table 3 Xtal/clock Frequency Settings for Program Block 3 .............................................................................................................. 20 Table 4 BOOTEN Pin States ................................................................................................................................................................ 22 Table 5 Inband Tones ......................................................................................................................................................................... 28 Table 6 DTMF Tone Pairs ................................................................................................................................................................... 28 Table 7 Alternative Selcall Tone Sets ................................................................................................................................................. 29 Figure Page Figure 1 Block Diagram ........................................................................................................................................................................ 5 Figure 2 C-BUS Timing ....................................................................................................................................................................... 13 Figure 3 CMX7158 Recommended External Components ................................................................................................................. 16 Figure 4 CMX7158 Power Supply and Decoupling ............................................................................................................................. 18 Figure 5 C-BUS Transactions .............................................................................................................................................................. 21 Figure 6 FI Loading From Host ........................................................................................................................................................... 23 2021 CML Microsystems Plc Page 2 D/7158/2