sta33013tr STMicroelectronics, sta33013tr Datasheet - Page 21

• Manufacturer Part Number: sta33013tr
• Description: 2.0 Digital Audio Processor With Ffx Digital Modulator And Analog And Digital Inputs
• Manufacturer: STMicroelectronics

STA330
7
7.1
7.1.1
Analog-digital converter (ADC)
Functional description
The STA330 analog input is provided through a low-power, low-voltage, stereo, audio-ADC
front end designed for audio applications. It includes a programmable gain amplifier, anti-
aliasing filter, a low-noise microphone biasing circuit, a third-order, MASH2-1, delta-sigma
modulator, a digital decimating filter and a first-order DC-removal filter. This device is
fabricated using a 0.18
combined with high-density logic circuits.
The ADC works in a microphone-input (mic-in) mode and in a line-input mode.
If the line-input mode is selected, the ADC is configured in stereo and all conversion
channels are active.
If the microphone-input mode is selected, the ADC is configured in mono. The mono
channel is routed through the left conversion path, and the right conversion path is kept in
power-down mode to minimize power consumption. A programmable gain amplifier (PGA) is
available in mic-in mode, giving the possibility to amplify the signal from 0 to +42 dB in steps
of 6 dB.
Digital anti-aliasing filter characteristics
The digital filter characteristics are shown in
Table 12.
Pass band
Pass band ripple:
Fs mode
Fs_by_2 mode
Fs_by_4 mode
Stop band attenuation:
Fs mode
Fs_by_2 mode
Fs_by_4 mode
Group delay:
Fs mode
Fs_by_2 mode
Fs_by_4 mode
Digital filter characteristics
Parameter
µ
m CMOS process, where high-speed precision analog circuits are
Table
0.4535 * f
0.08 dB at 44.1 kHz
0.08 dB at 22.05 kHz
0.08 dB at 11.025 kHz
45 dB at 44.1 kHz
45 dB at 22.05 kHz
45 dB at 11.025 kHz
0.4 ms at 32 kHz
0.7 ms at 16 kHz
1.4 ms at 8 kHz
12.
S
Analog-digital converter (ADC)
Typical
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