MAX5474 MAXIM [Maxim Integrated Products], MAX5474 Datasheet - Page 6

• Manufacturer Part Number: MAX5474
• Description: MAX5474 Evaluation Kit
• Manufacturer: MAXIM [Maxim Integrated Products]

The MAX5474 EV kit software graphical user interface
(GUI) is a Windows program that provides a convenient
means to control the MAX5474, as shown in Figure 1.
Text in bold denotes user-selectable features in the
MAX5474 EV kit software. A mouse or the keyboard’s
TAB key is used to navigate various items on the main
window. The bottom left-side status bar of the main win-
dow provides the USB interface circuit communication
status. The bottom right-side status bar indicates the
presence or absence of the MAX5474 IC and opera-
tional status.
Upon starting the program, the MAX5474 EV kit soft-
ware automatically detects for the USB and interface
circuit connection. The MAX5474 EV kit enters normal
operating mode when the USB connection is detected.
The software Wiper Position and Wiper Input are ini-
tialized to midscale position at startup. Software initial-
ization sets the volatile register of the MAX5474 IC to
midscale. The NV memory remains unchanged. If the
USB connection is not detected, the software prompts
the user to retry, exit the program, or enter the demo
mode.
The MAX5474 EV kit software can enter the demo
mode, when the USB connection is not detected, by
pressing the Cancel button in the MAX5474 Evaluation
Kit Interface Circuit Popup Window (Figure 2). The soft-
ware can also enter the demo mode at any time using
the Options | Demo Mode pulldown menu item in the
software main window. When in demo mode, all soft-
ware communication to the EV kit circuit is disabled;
however, most of the software GUI is functional. Demo
mode allows the user to evaluate the software without
hardware connectivity. To exit demo mode, select
Options | Demo Mode again from the pulldown menu.
Note: When reentering normal operating mode from the
demo mode, the MAX5474 wiper position must be
reset. Reset the wiper by pressing the Reset button.
See the Nonvolatile Memory section for more details.
MAX5474 Evaluation Kit
Figure 2. MAX5474 Evaluation Kit Interface Circuit Popup Window
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Detailed Description of Software
_______________________________________________________________________________________
Software Startup
Demo Mode
Moving the Wiper Position track bar will update and
display the MAX5474 wiper position. Pressing the
Store button stores the MAX5474 wiper to the non-
volatile memory. Pressing the Reset button synchro-
nizes the software and wiper position by returning the
MAX5474 wiper to the midscale position.
The Wiper Input combo box accepts and displays a
number between 1 and 32 for the wiper input. The
Wiper Input also features a drop-down menu that
stores the last four user entries. After pressing the
Store button, the Wiper Stored edit box displays the
MAX5474 IC’s stored wiper position, and is read only.
Pressing the Up button increments the wiper one tap
position, while pressing the Down button decrements
the wiper one tap position. These buttons also move
the Wiper Position track bar to the respective position.
The MAX5474 wiper position is stored in nonvolatile
memory when the Store button is pressed. The
MAX5474 wiper returns to this position upon power-up.
To demonstrate the nonvolatile memory feature in soft-
ware operation, press the Store button to store the
wiper position to the nonvolatile memory. Power cycle
the EV kit by removing the shunt from jumper JU1 and
reinstalling the shunt after 5s or longer (to allow dis-
charge of bypass capacitors). Do not restart the soft-
ware. Use an ohmmeter to verify the resistance
between the L and W PCB pads.
Perform a Reset to synchronize the software and
MAX5474 IC wiper position. Pressing the Reset button
does not overwrite the MAX5474 nonvolatile memory.
Pressing the Factory Default button resets the wiper
position in the MAX5474 volatile and nonvolatile memo-
ry to the factory-default position. The factory-default
wiper position in the volatile and nonvolatile memory is
at midscale.
Nonvolatile Memory
Factory Default
Wiper Position
Up and Down