SM5865CM Datasheet, PDF (11/20 Pages) Nippon Precision Circuits Inc – D/A Converter for Digital Audio

SM5865CM
FUNCTIONAL DESCRIPTION
Analog Outputs
IOUTA, IOUTB
The SM5865CM input data in-phase signal is processed by noise shaper A and 31-level DEM-DAC with cur-
rent output on differential output A, and input data reverse-phase signal is processed by noise shaper B and 31-
level DEM-DAC with current output on differential output B. Differential outputs A and B also have separate
in-phase and reverse-phase outputs: A in-phase output and B reverse-phase output are connected internally and
output on IOUTA, and B in-phase output and A reverse-phase output are connected internally and output on
IOUTB.
The IOUTA and IOUTB current outputs are I/V converted by external circuit and then input to a differential
input op-amp to obtain the final analog signal.
RA, RB
Internal resistors are connected between IOUTA and RA pins and between IOUTB and RB pins, which serve
as the op-amp feedback resistors. The feedback resistors have a resistance of 4.7kΩ.
The I/V converter output gain can be adjusted by connecting external resistors in parallel or serial with the
internal resistors. Note, however, that the internal resistance can vary from device to device by ±10%, and if
external resistors are used, the output level changes depending on the difference between each resistor ratio. If
the I/V converter gain is increased, a dynamic range higher even than that given in “Analog Characteristics
(page 8)” can be obtained.
Data input
Noise shaper A
Noise shaper B
31 Level
DEM DAC
31 Level
DEM DAC
In-phase
output A
Inverse-phase
output A
In-phase
output B
Inverse-phase
output B
Figure 9. Analog outputs
RA
IOUTA
RB
IOUTB
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