EVAL-AD5370/2/3EBZ

Preliminary Technical Data

Rev. PrC | Page 4 of 12

Table 4. Summary of Link Positions

Link

Description

LK1

Determines if the USB interface is to be used

If this link is inserted the USB interface will generate the signals required to control the AD537x

If this link is removed the USB interface is not used and header J3 must be used to provde signals to the AD537x

LK3

Selects Source of the RESET signal

If this link is inserted the RESETsignal comes from either the RESET push-button being pressed or a RESET signal being issued

by the USB interface

If this link is removed the RESET signal must come for the header J3

LK4

Selects the Reference Source

If this link is in position A the 3V reference is selected

If this link is in position B the 5V reference is selected

If this link is in position C the voltage on SMB connector EXT_REF is selected

LK8

Selects the Source of the CLR signal

If this link is inserted the CLR signal comes from the USB interface

If this link is removed the CLR signal must come for the header J3

USING THE USB SOFTWARE

The evaluation board kit comes supplied with a CD containing

PC software allowing the user to control the evaluation board

via the USB interface. The software must be installed before the

evaluation board is connected to the USB port. The software

installation program usually runs automatically when the CD is

inserted in the drive but if this doesn’t happen the user should

double-click on the SETUP.EXE file in the root directory of the

CD. The software will be installed and shortcuts will be placed

on the Start Menu in a folder called Analog Devices. When the

software has been installed the evaluation board can be

connected to the USB port.

When the software is started the user is presented with a

selection box. The selection box presents a choice of all the high

channel count DACs in the AD536x and AD537x family. The

user should click the button appropriate to the board being

used.

The first tab in the main operating window, shown in Figure 6,

allows the user to send data to the registers of any of the DACs.

All the available channels are shown in the DAC selection

section. When one of the radio buttons is selected the lower

portion of the screen will show the values currently assigned to

that DAC channel. The X1A, X1B, M or C registers can be

updated simply by entering the desired code and clicking the X,

M or C button. Note that when the X button is pressed the X1A

or X1B register is updated according to the selection of the A/B

radio button.

To update the DAC output the user should click the LDAC

button.

The Input Code block allows the user to store several

commonly used values and select between them as required.

The second tab of the tabbed dialog box also allows the user to

change the contents of the Offset DACs. The values loaded to

the Offset DACs will not affect the output voltages until LDAC

is pulsed.

The third tab of the tabbed dialog box allows the user to assert

or negate the RESET, CLR and LDAC. The user can also write

24 bits directly to the part. This can be useful, for example, to

write to a group of channels using a single write operation. This

function operates independently from the rest of the software

so any changes made by a direct write will not be evident in the

rest of the software. For example, if the direct write changes the

X1 register of all channels to 0xFFFF the first tab in the main

operating window will not be updated and will continue to

show the previous values that were entered.

The fourth tab shows the expected output voltages based on the

values of the X, M and C registers from the main operating

window, the reference value and the Offset DAC value. These

values are recalculated every time the tab is viewed.