AD9884AKS-100 Analog Devices Inc, AD9884AKS-100 Datasheet - Page 23

• Manufacturer Part Number: AD9884AKS-100
• Description: IC FLAT PANEL INTERFACE 128-MQFP
• Manufacturer: Analog Devices Inc

Specifications of AD9884AKS-100

• Display Type: LCD
• Interface: Analog
• Current - Supply: 125mA
• Voltage - Supply: 3 V ~ 3.6 V
• Operating Temperature: -20°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 128-MQFP, 128-PQFP
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Configuration: -
• Digits Or Characters: -

In some cases, using separate ground planes is unavoidable. For
those cases, we recommend to at least place a single ground
plane under the AD9884A. The location of the split should be
at the receiver of the digital outputs. For this case it is even
more important to place components wisely because the current
loops will be much longer, (current takes the path of least resis-
tance). An example of a current loop:
PLL
Place the PLL loop filter components as close to the AD9884A
pins as possible.
Do not place any digital or other high frequency traces near
these components.
Use the values suggested in the data sheet with 5% tolerance
or less.
Outputs (Both Data and Clocks)
Try to minimize the trace length that the digital outputs have to
drive. Longer traces have higher capacitance, which requires
more current, which causes more internal digital noise.
Shorter traces reduce the possibility of reflections.
REV. C
Figure 27. Current Loop
–23–
Adding a series resistor of value 50 Ω–200 Ω can suppress
reflections, reduce EMI, and reduce the current spikes inside of
the AD9884A. If series resistors are used, place them as close to
the AD9884A pins as possible, (although try not to add vias or
extra length to the output trace in order to get the resistors closer).
If possible, limit the capacitance that each of the digital outputs
drives to less than 10 pF. This can easily be accomplished by
keeping traces short and by connecting the outputs to only one
device. Loading the outputs with excessive capacitance will
increase the current transients inside of the AD9884A, and
create more digital noise on its power supplies.
Digital Inputs
The digital inputs on the AD9884A were designed to work with
3.3 V signals. Connecting 5 V digital signals to the part may
cause damage. To accommodate 5 V digital signals, we recom-
mend adding a series resistor at the AD9884A pin of 1 kΩ. The
only exception is the two serial interface pins, SDA and SCL.
On these two pins, a resistor value of 150 Ω should be used and
it should be placed between the AD9884A pin and the pull-up
resistors.
Any noise that gets onto the HSYNC input trace will add jitter
to the system, so, try to minimize the trace length and try not to
run any digital or other high frequency traces near it.
Voltage Reference
Bypass with a 0.1 µF capacitor. Place it as close to the AD9884A
pin as possible. Make the ground connection as short as possible.
REFOUT is easily connected to REFIN with a short trace.
Avoid making this trace any longer than it needs to be.
When using an external reference, the REFOUT output,
while unused, still needs to be bypassed to ground with a
0.1 µF capacitor to avoid ringing.
AD9884A