Datasheet

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SLES014B − OCTOBER 2001 − REVISED AUGUST 2002
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functional description (continued)
de-emphasis control
The de-emphasis control can be selected by DEMP1 (pin 17) and DEMP0 (pin 16). See Table 5.
Table 5. De-Emphasis Control
DEMT1 (pin 17) DEMT0 (pin 16) AUDIO INTERFACE
LOW LOW OFF
LOW HIGH 48 kHz
HIGH LOW 44.1 kHz
HIGH HIGH 32 kHz
analog outputs
The PCM1606 includes six independent output channels, V
OUT
1 through V
OUT
6. These are unbalanced
outputs, each capable of driving 3.1 Vp-p typical into a 5-kΩ ac load with V
CC
= 5 V. The internal output amplifiers
for V
OUT
1 through V
OUT
6 are dc-biased to the common-mode (or bipolar zero) voltage, equal to V
CC
/2.
The output amplifiers include an RC continuous-time filter, which helps to reduce the out-of-band noise energy
present at the DAC outputs due to the noise shaping characteristics of the PCM1606’s delta-sigma D/A
converters. The frequency response of this filter is shown in Figure 7. By itself, this filter is not enough to
attenuate the out-of-band noise to an acceptable level for most applications. An external low-pass filter is
required to provide sufficient out-of-band noise rejection. Further discussion of DAC post-filter circuits is
provided in the Application Information section of this data sheet.
f − Frequency − Hz
−100
−80
−60
−40
−20
0
20
Level − dB
LEVEL
vs
FREQUENCY
110100 1k 10k 100k 1M 10M
Figure 7. Output Filter Frequency Response