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Mixed Signal & Analog
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TLC320AD80: Providing a Cost-Effective Advantage to Set-Top Box Audio Conversion
DALLAS (Nov. 4, 1996) -- The TLC320AD80 audio subsystem is designed
to meet the audio needs of a broad range of set-top box applications.
This device includes a high performance stereo audio DAC, analog
volume and balance control, analog TV baseband audio decoder,
de-emphasis filter, and an analog wide-band multiplexer. This
high level of integration provides an ideal, inexpensive solution
for set-top box audio. Key applications for TIs AD80 include:
The AD80 provides multiple audio paths in both the digital as well as the analog domain. The two analog stereo inputs and one monaural audio input can be routed through to the volume and balance controls. Also, the one differential audio input connects to the internal TV baseband audio decoder. The two digital audio serial ports can be selected as inputs to the DAC. This device has six audio input ports. The ports consist of two serial PCM audio inputs, two stereo analog audio inputs, and two monaural analog audio inputs. These ports have many features designed to decrease overall system cost. One of the monaural audio ports provides an internal decoder for TV baseband signals, which is generally very costly to implement externally. There is a selectable 50/15 ms de-emphasis filter for the PCM audio inputs. The AD80 has a flexible stereo data port, configurable to Philips I2S Protocol, and to left-justified or right-justified formats. It also has a SPI bus compatible control interface. The TLC320AD80 also provides digital filtering and on-chip timing and control.
The TLC320AD80 DAC offers a typical signal to noise ratio of 85
dB. Nominal power dissipation for the system is 260 mW with a
power-down mode to 95 mW typical. The sample rate for this device
can be varied from a minimum of 8 kHz to a maximum of 48 kHz.
The TLC320AD80 is available in the 64 pin TQFP package.
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