EVAL-AD5235EBZ Analog Devices Inc, EVAL-AD5235EBZ Datasheet - Page 23

• Manufacturer Part Number: EVAL-AD5235EBZ
• Description: BOARD EVALUATION FOR AD5235
• Manufacturer: Analog Devices Inc

Specifications of EVAL-AD5235EBZ

• Main Purpose: Digital Potentiometer
• Utilized Ic / Part: AD5235
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Secondary Attributes: -
• Embedded: -
• Primary Attributes: -

Because the AD5235 can also be supplied by dual supplies, the
general equation defining the output voltage at V
to ground for any given input voltages applied to Terminal A
and Terminal B is
Equation 3 assumes that V
resistance is minimized. Operation of the digital potentiometer in
divider mode results in more accurate operation over temperature.
Here, the output voltage is dependent on the ratio of the internal
resistors and not the absolute value; therefore, the drift improves
to 15 ppm/°C. There is no voltage polarity restriction between
Terminal A, Terminal B, and Terminal W as long as the
terminal voltage (V
PROGRAMMING EXAMPLES
The following programming examples illustrate a typical sequence
of events for various features of the AD5235. See Table 7 for the
instructions and data-word format. The instruction numbers,
addresses, and data appearing at the SDI and SDO pins are in
hexadecimal format.
Table 14. Scratchpad Programming
SDI
0xB00100
0xB10200
Table 15. Incrementing RDAC Followed by Storing the
Wiper Setting to EEMEM
SDI
0xB00100
0xE0XXXX
0xE0XXXX
0x20XXXX
The EEMEM values for the RDACs can be restored by power-
on, by strobing the PR pin, or by the two commands shown in
Table 16
V
W
.
(
D
)
SDO
0xXXXXXX
0xB00100
=
SDO
0xXXXXXX
0xB00100
0xE0XXXX
0xXXXXXX
1024
D
TERM
×
V
AB
) stays within V
W
Action
Writes Data 0x100 into RDAC1 register,
Wiper W1 moves to 1/4 full-scale
position.
Loads Data 0x200 into RDAC2 register,
Wiper W2 moves to 1/2 full-scale
position.
+
Action
Writes Data 0x100 into RDAC1
register, Wiper W1 moves to 1/4 full-
scale position.
Increments RDAC1 register by one to
0x101.
Increments RDAC1 register by one to
0x102. Continue until desired wiper
position is reached.
Stores RDAC2 register data into
EEMEM1. Optionally, tie WP to GND to
protect EEMEM values.
is buffered so that the effect of wiper
V
B
SS
< V
TERM
W
< V
with respect
DD
.
Rev. D | Page 23 of 32
(3)
Table 16. Restoring the EEMEM Values to RDAC Registers
SDI
0x10XXXX
Table 17. Using Left-Shift by One to Increment 6 dB Steps
SDI
0xC0XXXX
0xC1XXXX
Table 18. Storing Additional User Data in EEMEM
SDI
0x32AAAA
0x335555
Table 19. Reading Back Data from Memory Locations
SDI
0x92XXXX
0x00XXXX
Table 20. Reading Back Wiper Settings
SDI
0xB00200
0xC0XXXX
0xA0XXXX
0xXXXXXX
EVAL-AD5235SDZ EVALUATION KIT
Analog Devices, Inc., offers a user-friendly EVAL-AD5235SDZ
evaluation kit that can be controlled by a PC in conjunction
with the
no programming languages or skills are needed.
SDP
SDO
0xXXXXXX
SDO
0xXXXXXX
0x92AAAA
SDO
0xXXXXXX
0xB00200
0xC0XXXX
0xA003FF
SDO
0xXXXXXX
0x32AAAA
platform. The driving program is self-contained;
SDO
0xXXXXXX
0xC0XXXX
Action
Restores the EEMEM1 value to the
RDAC1 register.
Reads back full-scale value from SDO.
Action
Writes RDAC1 to midscale.
Doubles RDAC1 from midscale to full
scale.
Prepares reading wiper setting from
RDAC1 register.
Action
Prepares data read from USER1
EEMEM location.
NOP Instruction 0 sends a 24-bit word
out of SDO, where the last 16 bits
contain the contents in USER1 EEMEM
location.
Action
Stores Data 0xAAAA in the extra
EEMEM location USER1. (Allowable to
address in 13 locations with a
maximum of 16 bits of data.)
Stores Data 0x5555 in the extra
EEMEM location USER2. (Allowable to
address in 13 locations with a
maximum of 16 bits of data.)
Action
Moves Wiper 1 to double the
present data contained in the
RDAC1 register.
Moves Wiper 2 to double the
present data contained in the
RDAC2 register.
AD5235