max5858 Maxim Integrated Products, Inc., max5858 Datasheet - Page 16

• Manufacturer Part Number: max5858
• Description: Max5858 Dual, 10-bit, 300msps, Current-output Dac With 4x/2x/1x Interpolation Filters
• Manufacturer: Maxim Integrated Products, Inc.

Dual, 10-Bit, 300Msps, Current-Output DAC with
4x/2x/1x Interpolation Filters
Figure 3. MAX5858 in 4x Interpolation Mode
This example demonstrates that 4x interpolation with
digital filtering yields significant benefits in reducing
system complexity, improving dynamic performance
and lowering cost. Data can be written to the MAX5858
at much lower speeds while achieving image attenua-
tion greater than 60dB and image separation beyond
three octaves. The main benefit is in analog reconstruc-
16
______________________________________________________________________________________
SOLUTION 1
SOLUTION 2
SOLUTION 3
20MHz ±10MHz
BW = ±10MHz
BW = ±10MHz
20MHz
20MHz
f
f
f
OUT
OUT
OUT
FREQUENCY AXIS NOT TO SCALE
FREQUENCY AXIS NOT TO SCALE
FREQUENCY AXIS NOT TO SCALE
f
DAC
48MHz
IMAGE
- f
SIMPLE ANALOG FILTER
OUT
ANALOG FILTER
LOWER ORDER
ATTENUATION >60dB
71.6MHz
78MHz
DIGITAL FILTER
f
f
DATA
DAC
tion filter design. Reducing the filter order eases
gain/phase matching while lowering filter cost and sav-
ing board space. Because the data rate is lowered to
71.6MHz, the setup and hold times are manageable
and the clock signal source is simplified, which results
in improved system reliability and lower cost.
f
DAC
108MHz
f
IMAGE
DAC
210MHz
IMAGE
NEW FIRST IMAGE SEPARATION > 3 OCTAVES
+ f
- f
OUT
OUT
IMAGE SEPARATION = 180MHz
IMAGE SEPARATION = 18MHz
HIGH ORDER ANALOG FILTER
HIGH-SPEED CLK = 240MHz
240MHz
LESS THAN ONE OCTAVE
f
f
DAC
DAC
256MHz
IMAGE
- f
OUT
f
DAC
270MHz
IMAGE
286MHz
+ f
f
DAC
OUT
f
DAC
316MHz
IMAGE
+ f
OUT