Traditionally voice codes have interfaced to electret microphones and speakers providing A to D and D to A functions, using precision oversampling data converters. Recent advances in microphone design using MEMS techniques are now changing this, along with higher efficiency speaker driver architectures such as Class D topologies. Both of these advances enable significant reductions in power consumption which is needed to address new applications such as voice control, that require always-on operation. Such applications that are often battery powered, driving the need for ultra-low power consumption.
The CMX655D addresses these needs, providing an update to the traditional voice codec, that is both very low power and small in size. Microphone interfaces connect single or dual MEMS microphones to the device, with parallel processing of each data stream to maintain phase alignment between the two channels.
In the reverse channel, digital voice data drives a Class D speaker driver, also featuring programmable filtering and digital gain control. This architecture operates with much higher efficiency than conventional speaker drivers. An additional low level output is also provided.
The device interfaces via standard serial busses that are commonly found on many microcontrollers, DSPs and low cost single chip radio transceivers.
The CMX655D is available in a small VQFN-24 package and supported by a range of development tools, including the EV6550D evaluation kit.
Devices are available through our distributors below:
|The PE0003 Evaluation Kit Interface Card is a global interface system for use with evaluation kits for CML’s new generation ICs, including FirmASIC™ based products. This greatly simplifies the approach to the evaluation and design-in process.||Link to:
|The EV6550D and EV6550A Evaluation Kits are designed to assist in the evaluation and application development of the CMX655D and CMX655A. The EV6550D/EV6550A is designed to interface with MEMS (Micro-Electro Mechanical System) microphone evaluation boards.
EV6550D High Resolution Schematics. Version B03. – Download
EV6550D Gerbers. Version B01. – Download
EV6550D GUI. A Windows PC GUI for configuring and using the EV6550D. Revision 1.0. A PE0003 Evaluation Kit Interface Card is required to use this GUI. – Download
EV6550D High Resolution PCB Overlay. Version B01. – Download
VQFN Design Guidance Notes