CS5126 Cirrus Logic, CS5126 Datasheet - Page 12

• Manufacturer Part Number: CS5126
• Description: 16-Bit Stereo A/D Converter for Digital Audio
• Manufacturer: Cirrus Logic

at 30kHz and 45kHz. Meanwhile, digital filters
such as the SM5805 shown in Figure 10 will
roll-off rapidly from 22kHz to 28kHz and reject
distortion energy in the second, third, and fourth
harmonics. Clearly, oversampling results in su-
perior system-level distortion.
Still, if the CS5126’s distortion performance
with high-frequency, high-amplitude signals
must be enhanced in 2X oversampling schemes,
the TRKL or TRKR outputs can be used. Either
TRKL or TRKR will fall at the end of each con-
version cycle depending on which channel is be-
ing acquired. The AINL and TRKL connections
(or AINR and TRKR) can be used as shown in
Figure 11 to control an external low-distortion
sample/hold to create an effective dc input for
the CS5126 and remove sampling distortion.
Digital Circuit Connections
When TTL loads are utilized the potential for
crosstalk between digital and analog sections of
the system is increased. This crosstalk is due to
high digital supply and signal currents arising
from the TTL drive current required of each
digital output. Connecting CMOS logic to the
digital outputs is recommended. Suitable logic
families include 4000B, 74HC, 74AC, 74ACT,
and 74HCT.
12
Right Channel
Left Channel
Analog In
Analog In
Anti Alias
Anti Alias
Filter
Filter
+5V
Figure 10. Example Oversampling System Diagram
AINL
L/R
L/R
AINL
CS5126
CS5126
SDATA
SDATA
CLKIN
CLKIN
HOLD
HOLD
SCLK
SCLK
The CS5126 has a power down mode, initiated
by bringing SLEEP low. During power down,
the A/D Converter’s calibration information is
retained. The CS5126 may be used for conver-
sion immediately after SLEEP is brought high.
Signal
Amplitude
Relative to
Full Scale
Figure 12. FFT Plot of CS5126 in Monaural 2X Over-
Figure 11. High-Slew Monaural Connections
Analog In
DINL
IBO
IBCK
DINR
-100dB
-120dB
Left
-20dB
-40dB
-60dB
-80dB
Digital Filter
+5V
0dB
SM5805
1 kHz
WDCK
OBCK
LRCK
CKIN
DOL
sampling Mode
S/H
Input Frequency
AINL
TRKL
L/R
512 f s
256 f s
32 f s
2 f s
f s
DATA IN
Sampling Rate: 96 kHz
Full Scale: 9V p-p
S/(N+D): 91.44 dB
S/(N+D): 95.25 dB
(dc to 20 kHz)
System
CS5126
DS32F1
48kHz