Tackling hands-free challenges and suppressing ambient noise with voice processor

Tackling hands-free challenges and suppressing ambient noise with voice processor

Any system designer assigned to a project involving acoustics know inexpensive transducers combined with small and thin industrial designs can be very challenging. Feats impossible to be achieved are typically asked of them. Small microphones for voice input sometimes have to be placed very close to the speaker and loud output is expected from the transducer in less than ideal chamber designs.

Fortemedia SAM™ voice processors come to the rescue of system designers and project managers facing such obstacles. They have been used in countless industrial, commercial and consumer projects requiring speakerphone functions, such as security intercom terminals, hands-free car kits, iPhone docks with speakers, mobile phones and PCs. 

Depending on the system partitioning either the analog I/O FM11xx or digital only FM31-3xx series SAM voice processors present themselves with the right feature set for a seamless integration. In addition these two families give you options for selecting analog or digital microphones for your design. 

These embedded processors solve challenging voice input and output design requirements. The advantages of SOC are quicker system integration compared to software competing for the same host hardware resources and integration stability challenges requiring rigorous testing. The boundaries of each function are also well defined. In addition voice processing SOCs are independent of operating system, removing the need for porting and retesting in each instance. Embedded voice processors are a staple in wired and wireless accessories, mobile handsets and other voice communication terminals.

The low power FM1188, the latest addition to the family, like its predecessors, comes with its embedded ADCs and DACs supporting up to 2-mics. Noise Suppression and Acoustic Echo Cancellation operates @ 8kHz sampling rate. The SOC can be controlled by the host via I²C and PCM data option is available as an alternate to the ADC/DAC line level I/O. In extended temperature grade, it is available in 48-pin LQFP and BGA packages while the Auto grade is only available in LQFP form.

In contrast, the FM31-3xx family is a pure digital voice processor delivered in a small 24-pin QFN package in extended temperature grade. With FM31-3xx series the designer has the option to use digital microphones or an external codec that supports conventional ECMs. The FM31 voice processing is at 16kHz while it can interface to 8kHz sampling hosts. It supports both single channel PCM or dual channel PCM on I²S typically associated with stereo audio.

We encourage system designers and project managers to review the system block diagram below showing how Fortemedia SAM processors are typically deployed in designs.