PCM1738E2K BURR-BROWN [Burr-Brown Corporation], PCM1738E2K Datasheet - Page 29

• Manufacturer Part Number: PCM1738E2K
• Description: 24-Bit, 192kHz Sampling, Advanced Segment, Audio-Stereo DIGITAL-TO-ANALOG CONVERTER
• Manufacturer: BURR-BROWN [Burr-Brown Corporation]

PCM1738
The PCM1738 utilizes the newly developed Advanced Seg-
ment DAC architecture to achieve excellent dynamic perfor-
mance and improved tolerance to clock jitter. The PCM1738
provides balanced current outputs, allowing the user to
optimize analog performance externally. The structure of the
Advanced Segment DAC architecture is shown in Figure 13.
Digital input data from the digital interpolation filter is split
into six upper bits and 18 lower bits. The upper six bits are
converted to ICOB (Inverted Complementary Offset Binary)
code. The lower 18 bits associated with the MSB are
processed by fifth-level, third-order, delta-sigma modulators
operated at 64f
modulator is equivalent to 1LSB of the above code con-
THEORY OF OPERATION
ADVANCED SEGMENT DAC
FIGURE 13. Architecture of Advanced Segment DAC.
SBAS174B
S
by default conditions. The first level of the
Digital
24-Bit
Input
8f
S
Lower 18 Bits
MSB and
Upper
6 Bits
3rd-Order,
5th-Level,
Decoder
ICOB
0 • 62
Level
0 • 4
Level
+
0 • 66
verter. The data groups processed in the ICOB converter and
the third-order delta-sigma modulator are summed together
to create up to 67 levels of digital code that is then processed
by the DWA (Data Weighted Averaging) to reduce noise
produced by element mismatch. The output data from the
DWA block is then converted to an analog output using a
differential current segment DAC.
To learn more details regarding the Advanced Segment
DAC architecture, please refer to the paper presented at the
109
rent-mode, Multi-Bit, Audio DAC for PCM and DSD Audio
Playback” by Nakao, Terasawa, Aoyagi, Terada, and
Hamasaki of Burr-Brown Japan (now part of Texas Instru-
ments).
Advanced
th
DWA
AES Convention entitled “A 117db, D-Range, Cur-
Segment
Current
DAC
Analog
Output
29