Rainbow Electronics MAX5559 - Manual (Page 8)

MAX5556–MAX5559
Low-Cost Stereo Audio DACs
8 ________________________________________________________________________________________
Integrated Analog Lowpass Filter
The DAC output of the sigma-delta modulator is fol-
lowed by an analog smoothing filter that attenuates
high-frequency quantization noise. The corner frequen-
cy of the filter is approximately 2 x f
S .
Integrated Analog Output Buffer
Following the analog lowpass filter, the analog signal is
routed through internal buffers to OUTR and OUTL. The
buffer can directly drive load resistances larger than
3kΩ and load capacitances up to 100pF (Figure 3).
INTERPOLATOR
SIGMA-DELTA
MODULATOR
SIGMA-DELTA
MODULATOR
ANALOG
LOWPASS
FILTER
ANALOG
LOWPASS
FILTER
SDATA
MCLK
LRCLK
SCLK
OUTL
OUTR
V DD
GND
DAC
DAC
BUFFER
INTERNAL
REFERENCE
INTERPOLATOR
BUFFER
MAX5556–MAX5559
SERIAL
INTERFACE
LOAD RESISTANCE R L (kΩ)
3
5 10 15 20
125
100
75
50
25
SAFE OPERATING REGION
25
LOAD CAP
ACIT
ANCE C
L
(pF)
Figure 2. Functional Diagram
Figure 3. Load-Impedance Operating Region