AD8320ARP datasheet(15/20 Pages) AD

15 / 20 page

AD8320

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Figure 52. Evaluation Board Silkscreen (Component Side)

The control software requires Windows 3.1 or later to operate.

To install the software, insert the disk labeled “Disk # 1 of 2” in

the PC and run the file called SETUP.EXE. Additional installa-

tion instructions will be given on-screen. Before beginning installa-

tion, it is important to close any other Windows applications

that are running.

When you launch the installed control software from Windows,

you will be asked to select the printer port you are using. Most

modern PCs have only one printer port, usually called LPT1.

However, some laptop computers use the PRN port.

Figure 56 shows the main screen of the control software. Using

the slider, you can set any gain in the AD8320’s 36 dB range.

The gain is displayed on-screen in dB and V/V. The 8-bit gain

setting byte is also displayed, in binary, hexadecimal and decimal.

Each time the slider is moved, the software automatically sends

and latches the required 8-bit data stream to the AD8320. You

can power down or reset the device simply by clicking the

appropriate buttons. The software also offers one volatile stor-

age location that can be used to store a particular gain. This

functions in the same way as the memory on a pocket calculator.

Overshoot on PC Printer Ports’ Data Lines

The data lines on some printer ports have excessive overshoot.

Overshoot on the pin used as the serial clock (Pin 6 on the D-

Sub-25 connector) can cause communication problems. This

overshoot can be eliminated by applying mild filtering to the

CLK line on the evaluation board. This can be done by putting

a small series resistor on the CLK line, combined with a

capacitor to ground. Pads are provided (C9, R4) on the com-

ponent side of the evaluation board to allow easy insertion of

these devices. Determining the size of these values will take

some experimentation. Depending upon the overshoot from the

printer port, this capacitor may need to be as large as 0.01

µF,

while the resistor is typically in the 50

Ω to 100 Ω range.

AD8320ARP Datasheet(PDF) 15 Page - Analog Devices