Table 4. benefits of interpolation – Rainbow Electronics MAX5858 User Manual
Page 15
MAX5858
Dual, 10-Bit, 300Msps, Current-Output DAC with
4x/2x/1x Interpolation Filters
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15
SINGLE 10-BIT BUS
SAVES I/O PINS
DATA CLOCK OUT
f
DATA
= 71.6MHz
CLOCK SOURCE
f
DAC
= 286.4MHz
INTERLEAVE
DATA
LATCH
DATA
LATCH
10-BIT
DIGITAL BASEBAND
OFDM PROCESSOR
QAM-MAPPER
FS ANALOG OUT
MAINTAINED OVER
ENTIRE SUPPLY RANGE
2.7V TO 3.3V
DATA
LATCH
10-BIT BUS
DIV-4
DIV-2
DIV-1
INTERPOLATING
FILTERS
4x/2x
SINGLE SUPPLY
2.7V TO 3.3V
CH-1
DAC
CH-2
DAC
AOUT2
AOUT1
INTERPOLATING
FILTERS
4x/2x
Figure 2. Typical Application Circuit
OPTION
SOLUTION
ADVANTAGE
DISADVANTAGE
1
• No interpolation
• 2.6x oversample
• f
DAC
= f
DATA
= 78MHz
• Low data rate
• Low clock rate
• High order filter
• Filter gain/phase match
2
• No interpolation
• 8x oversample
• f
DAC
= f
DATA
= 240MHz
• Push image to f
IMAGE
= 210MHz
• Lower order filter
• Filter gain/phase match
• High clock rate
• High data rate
3
• 4x interpolation
• f
DAC
= 286.4MHz, f
DATA
= 71.6MHz
• Passband attenuation = 0.1dB
• Push image to 256MHz
• Low data rate
• Low order filter
• 60dB image attenuate
• Filter gain/phase match
• None
Table 4. Benefits of Interpolation