max5187beeg Maxim Integrated Products, Inc., max5187beeg Datasheet - Page 14

• Manufacturer Part Number: max5187beeg
• Description: 8-bit, 40mhz, Current/voltage-output Dacs
• Manufacturer: Maxim Integrated Products, Inc.

8-Bit, 40MHz, Current/Voltage-Output DACs
Figure 8a. Traditional Arbitrary Waveform Generation (AWG)
Figure 8b. Direct Digital Synthesis AWG (DDS AWG)
ic interference (EMI) can either couple into or be gener-
ated by the MAX5187/MAX5190. Therefore, grounding
and power-supply decoupling guidelines for high-
speed, high-frequency applications should be closely
followed.
First, a multilayer PC board with separate ground and
power-supply planes is recommended. High-speed
signals should be run on controlled impedance lines
directly above the ground plane. Since the MAX5187/
MAX5190 have separate analog and digital ground
buses (AGND and DGND, respectively), the PC board
should also have separate analog and digital ground
sections with only one point connecting the two. Digital
signals should run above the digital ground plane, and
analog signals should run above the analog ground
plane.
Both devices have two power-supply inputs: analog
V
should be decoupled with parallel 10µF and 0.1µF
14
DD
______________________________________________________________________________________
*MAX5187 ONLY
(AV
INCREMENT
REGISTER
PHASE
PIR
DD
GENERATOR
) and digital V
CLOCK
*MAX5187 ONLY
D
D
A
E
R
COUNTER
CLOCK
GENERATOR
DD
FEEDBACK LOOP
ACCUMULATOR
ACCUMULATOR
FOR DATA BITS
(DV
PHASE
DD
ADR
). Each AV
ADR
WAVEFORM
MEMORY
(RAM)
DD
WAVEFORM
MEMORY
input
(RAM)
8
9.6k*
8
DATA
ceramic chip capacitors. These capacitors should be
as close to the pin as possible, and their opposite ends
should be as close as possible to the ground plane.
The DV
0.1µF capacitors adjacent to their respective pins. Try
to minimize the analog load capacitance for proper
operation. For best performance, bypass with low-ESR
0.1µF capacitors to AV
The power-supply voltages should also be decoupled
with large tantalum or electrolytic capacitors at the
point they enter the PC board. Ferrite beads with addi-
tional decoupling capacitors forming a pi-network can
also improve performance.
TRANSISTOR COUNT: 9464
SUBSTRATE CONNECTED TO AGND
9.6k*
AV
MAX5187
MAX5190
DD
REFR
AV
DV
MAX5187
MAX5190
DD
DD
DD
DV
pins should also have separate 10µF and
DD
400Ω*
400Ω*
RECONSTRUCTION
DD
LOWPASS
VARIABLE
RECONSTRUCTION
.
FILTER
f
C
LOWPASS
VARIABLE
Chip Information
FILTER
f
C
(ANALOG OUTPUT)
WAVEFORM
FILTERED
(ANALOG OUTPUT)
WAVEFORM
FILTERED