AD9929BBCZ datasheet(60/64 Pages) AD

60 / 64 page

AD9929

Rev. A | Page 60 of 64

CIRCUIT LAYOUT INFORMATION

The AD9929 typical circuit connection is shown in Figure 71.

The PCB layout is critical in achieving good image quality from

the AD9929 product. All of the supply pins must be decoupled

to ground with good quality, high frequency chip capacitors.

The 0.1 µF decoupling capacitors should be located as close as

possible to the supply pins, and should have a very low induc-

tance path to a continuous ground plane. There should also be a

4.7 µF or larger capacitor for each main supply, although it is

not necessary for each individual pin.

In most applications it is easier and recommended to share the

same supply for AVDD, DVDD, TCVDD, RGVDD, and HVDD,

as long as the individual supply pins are separately bypassed at

each supply pin. A separate 3 V supply should be used for

DRVDD with this supply pin decoupled to the same ground

plane as the rest of the chip. A separate ground for DRVSS is not

recommended.

The vertical driver VM supply pins can be connected to indi-

vidual supplies or to the same supply, depending on the appli-

cation requirement for the mid-level voltage on the vertical

outputs. These pins may also be directly connected to the

common ground plane, as shown in Figure 71.

The analog bypass pins, REFB, REFT, should also be carefully

decoupled to ground as close as possible to their respective pins.

The analog input, CCDIN, capacitor should also be located

close to the pin.

The H1, H2, and RG printed circuit board traces should be

designed to have low inductance to avoid excessive distortion of

the signals. Heavier traces are recommended because of the

large transient current demand by the CCD on H1 and H2. If

possible, physically locate the AD9929 close to the CCD to

reduce the inductance on these lines. As always, the routing

path should be as direct as possible from the AD9929 to the

CCD. Careful trace impedance considerations must also be

made with applications using a flex printed circuit (FPC) con-

necting the CCD to the AD9929. FPC trace impedances can be

controlled by applying a solid uniform ground plane under the

H1, H2, and RG traces. This helps minimize the amount of

overshoot and ringing on these signals at the CCD inputs.

AD9929BBCZ Datasheet(PDF) 60 Page - Analog Devices