AD7910 datasheet(18/20 Pages) AD

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REV. B

–18–

AD7910/AD7920

As can be seen in Figure 18, for the MSOP package the decou-

pling capacitor has been placed as close as possible to the IC, with

short track lengths to VDD and GND pins. The decoupling capaci-

tor could also be placed on the underside of the PCB directly under-

neath the IC, between the VDD and GND pins attached by vias.

This method would not be recommended on PCBs above a standard

1.6 mm thickness. The best performance will be seen with the decou-

pling capacitor on the top of the PCB next to the IC.

Figure 18. Recommended Supply Decoupling

Scheme for the AD7910/AD7920 MSOP Package

Similarly, for the SC70 package, the decoupling capacitor should

be located as close as possible to the VDD and GND pins. Because

of its pinout, i.e., VDD being next to GND, the decoupling capaci-

tor can be placed extremely close to the IC. The decoupling

capacitor could be placed on the underside of the PCB directly

under the VDD and GND pins, but, as before, the best perfor-

mance will be seen with the decoupling capacitor on the same

side as the IC.

Figure 19. Recommended Supply Decoupling

Scheme for the AD7910/AD7920 SC70 Package

Evaluating the AD7910/AD7920 Performance

The evaluation board package includes a fully assembled and

tested evaluation board, documentation, and software for con-

trolling the board from the PC via the Eval-Board Controller.

To demonstrate/evaluate the ac and dc performance of the

AD7910/AD7920, the evaluation board controller can be used

in conjunction with the AD7910/AD7920CB evaluation boards

as well as many other Analog Devices evaluation boards ending

in the CB designator.

The software allows the user to perform ac (fast Fourier transform)

and dc (histogram of codes) tests on the AD7910/AD7920. See

the evaluation board technical note for more information.

AD7910 датащи(PDF) 18 Page - Analog Devices