MAX5386MEVMINIQU+ Maxim Integrated, MAX5386MEVMINIQU+ Datasheet - Page 6

• Manufacturer Part Number: MAX5386MEVMINIQU+
• Description: Digital Potentiometer ICs MAX5386/88/91/93 Eval Kit
• Manufacturer: Maxim Integrated

Specifications of MAX5386MEVMINIQU+

• Rohs: yes
• Resistance: 10 kOhms
• Temperature Coefficient: 35 PPM / C
• Tolerance: 25 %
• Number Of Pots: Dual
• Taps Per Pot: 256
• Wiper Memory: Volatile
• Digital Interface: Serial (3-Wire, SPI)
• Description/function: Dual Volatile Low Voltage Linear Taper Digital Potentiometer
• Operating Supply Voltage: 2.6 V to 5.5 V
• Supply Current: 1 uA
• Supply Voltage - Max: 5.5 V
• Supply Voltage - Min: 2.6 V

MAX5386M Evaluation System
Pressing the Default button resets potentiometer A and
B wiper positions in the MAX5386M to the factory-default
midscale position.
The Status indicator in the Interface group box displays
EV_ Kit_ Operational when the EV kit enters the normal
operating mode after the USB connection is detected.
If the USB connection is not detected, or when the
software enters the demo mode, the Status indicator
displays Demo_ Mode. Demo mode is used to exercise
the software without hardware connectivity.
The Command_ Sent indicator in the Interface group
box displays the last command sent from the master
(software) to the MAX5386M. There are two commands
available in the MAX5386M IC. Table 2 describes the two
MAX5386M commands.
The Data_Sent indicator displays the last data sent from
the masters to potentiometer A (0x00) or potentiometer
B (0x01) registers.
The MAX5386M IC uses an 8-bit (MSBs, D7–D0) data
byte to set the wiper position. Refer to the MAX5386 IC
data sheet for additional information.
Press the Tab key to select each GUI control. The select-
ed control is indicated by a dotted outline. Using Shift
+ Tab moves the selection to the previously selected
control. Buttons respond to the keyboard’s space bar
and some controls respond to the keyboard’s up and
down arrow keys. Activate the program’s menu bar by
pressing the F10 key and then pressing the letter of the
desired menu item. Most menu items have one letter
underlined, indicating their shortcut key.
When a number is entered into the edit boxes, it can be
sent to the device by pressing the Enter key. It is also
sent when Tab or Shift + Tab is pressed.
Table_2._MAX5386M_SPI_Command
6_ _ _______________________________________________________________________________________
MAX5386M_
REGISTER
VREGA
VREGB
Command Sent Indicator
00000000
00000001
BINARY
Keyboard Navigation
COMMAND
Data Sent Indicator
Status Indicator
Factory Default
0x00
0x01
HEX
SPI data is written to potentiometer A. Wiper WA position updates with
SPI data.
SPI data is written to potentiometer B. Wiper WB position updates with
SPI data.
There are two methods for communicating with the EV
kit, through the normal user-interface panel (Figure 1)
or through the SPI commands available by selecting
the 3-Wire_Interface (Figure 3) utility from the main pro-
gram’s Options_|_Advanced_Users Interface menu bar.
A window is displayed that allows SPI send/receive data
operations.
On the 3-wire_interface tab, the Connection group box
defines the hardware connections of the interface. For
the EV kit, K10 is selected from the Clock_(SCK)(SCLK)
drop-down list, K12 from the Data_from_master_to_slave_
(MOSI)(DIN) drop-down list is disabled, K11 from the
Data_ from_ slave_ to_ master_ (MISO)(DOUT) drop-down
list, K9 from the Chip-select_ (CS)_ for_ data_ framing
drop-down list, and Use_ standard_ connections_ for_
high-speed_SPI checkbox is checked (see Figure 3).
The Configuration group box allows the user to config-
ure the logic level and data rate. For the EV kit, check
the Send_&_Receive_MSB_first checkbox and verify that
the CPOL=1(clock_idle_high) and CPHA=1(sample_2nd_
edge)_checkboxes are unchecked (see Figure 3).
The Send_and_Receive_Data group box allows the user
to send data to the MAX5386M. The Data_ bytes_ to_ be_
written_edit box indicates data to be sent from the mas-
ter (microcontroller) to the device (MAX5386M). Eight-
bit hexadecimal numbers should be comma delimited.
Press the Send_Now button to transmit the data from the
master to the device. Data appearing in the Data_bytes_
received edit box is data read from the device. The Data_
bytes_ received edit box in the EV kit software always
shows a default value of 0xFF since the MAX5386M
does not send data back to the master.
Note: The SPI dialog boxes accept numeric data in
hexadecimal format. Hexadecimal numbers must be pre-
fixed by $ or 0x. Figure 3 shows a simple SPI write-byte
operation using the included 3-wire interface diagnostics
tool. In this example, the software is sending command
0x00 (write to potentiometer A) and data 0x7F. The data
sequence sets the MAX5386M wiper position to 127.
DESCRIPTION
Simple SPI Commands