Low-Voltage Codecs
The codecs provide functionality to support analog-to-digital, and digital-to-analog conversions, with integrated gain control and programmable side-tone path, on-chip anti-alias filters, reference voltage and bias source. The analog output enables the devices to drive "hands-free" speaker systems, while the digital portion interfaces with many different operating structures to support connections between the new digital infrastructure and the existing analog network.
The MT91L60 and MT91L61 3V codecs use Mitel's advanced circuit design techniques to reduce active power to 30mW compared to 80mW in comparable solutions. This enables the circuits to accommodate a range of line card applications, and eases system upgrades by allowing operation in both 3-volt and 5-volt processes with little increase in current.
The devices incorporate all of the functions required to convert analog signals to digital for network transmission, requiring only a +3V rail.
Eliminating the additional negative rail required by competitive solutions lowers cost while simplifying system design. Unlike many alternatives, the MT91L60 and MT91L61 drive the audio signal into a handset, and can be 'daisy chained' together for multiple line applications. The approach eases integration and time-to-market, while accommodating the increased line requirements of emerging applications.
Fully compliant with the ITU-T G.711, G.712, and G.714 standards, the new line card components comprise an off-the-shelf solution that consistently meets the expectations for voice quality performance in worldwide systems.
The devices are priced at approximately $3.15 in quantities of 10k units (pricing at time of publication).
Mitel Semiconductor, 350 Legget Drive, P.O. Box 13089, Kanata, Ontario, Canada K2K 2W7, Tel: (613) 592-2122, Fax: (613) 592-4784