The new MAX9860 from Maxim is a low-power, mono audio codec with dual ADC paths and programmable digital voice filters. The device employs a flexible clocking scheme that utilises common system clock frequencies ranging from 10 MHz to 60 MHz, eliminating the need for an external PLL and multiple crystal oscillators. The device is targeted at applications such as voice headsets, digital cameras, cellphones, portable recorders, VoIP telephones and conference phones.
The MAX9860 includes two differential microphone inputs with a user-programmable preamplifier and programmable gain amplifier. Automatic gain control with selectable attack/release times and a signal threshold allows maximum dynamic range. A noise gate with a selectable threshold helps quiet the audio channel when no signal is present. This configuration allows the user to select one channel for voice, while the other channel can be converted and processed downstream for echo-noise cancelling and background noise.
The programmable digital voice filters provide full attenuation for out-of-band signals, as well as a 5th-order, GSM-compliant digital high-pass filter. An elliptical digital filter notches the 217 Hz (GSM) frequency for 8 kHz and 16 kHz sample rates. Also, an available digital side-tone mixer provides loopback of the ADC signal (microphones) to the DAC output (headphone) in the case of a headset application.
The analog output is a bridge-tied-load (BTL), mono headphone amplifier. The MAX9860 can output 30 mW into a 32 earpiece while operating from a single 1,8 V power supply. This low-voltage operation translates into low power consumption that makes the IC suitable for battery-powered applications.
The MAX9860 includes two serial data interfaces. The ADC and DAC data is transferred over a flexible digital I²S-compatible interface that also supports TDM mode. General mode settings, including volume control, digital filters, and shutdown, are all programmed through a 2-wire, I²C-compatible interface.
For more information contact Larry Gordon, CST Electronics, +27 (0)11 608 0070, [email protected], www.cstelectronics.co.za
| Tel: | +27 11 608 0070 |
| Email: | [email protected] |
| www: | www.cstelectronics.co.za |
| Articles: | More information and articles about CST Electronics |
© Technews Publishing (Pty) Ltd | All Rights Reserved
printer friendly version