CAT5129 CATALYST [Catalyst Semiconductor], CAT5129 Datasheet - Page 3

• Manufacturer Part Number: CAT5129
• Description: 32-Tap Digitally Programmable Potentiometer (DPP TM)
• Manufacturer: CATALYST [Catalyst Semiconductor]

DEVICE OPERATION
The CAT5127 operates like a digitally controlled
variable resistor with R
and low terminals. There are 32 available tap posi-
tions including the resistor end points, R
There are 31 resistor elements connected in series
between the R
The CAT5129 operates like a digitally controlled
variable resistor with R
terminal. There are 32 available tap positions
including the resistor end points, R
are 31 resistor elements connected in series between
the R
Operation is controlled by three inputs, INC
CS
whose output is decoded to select the wiper position.
The selected wiper position can be stored in
nonvolatile memory using the INC
OPERATION MODES
© 2006 Catalyst Semiconductor, Inc.
Characteristics subject to change without notice
¯¯ . These inputs control a five-bit up/down counter
High to Low
High to Low
H
High
Low
¯¯¯
INC
X
and GND terminals.
H
and R
Low to High
Low to High
High
Low
Low
CS
¯¯
L
H
terminals.
and R
H
equivalent to the high
¯¯¯ and CS
L
equivalent to the high
High
Low
U/D ¯
X
X
X
H
and GND. There
Variable Resistor Equivalent Circuit
¯¯ inputs.
¯¯¯ , U/D ¯ and
No Store, Return to Standby
H
Wiper toward L/GND
Store Wiper Position
and R
Wiper toward H
C
C
Operation
H
L
Standby
L
.
3
R
L
/GND
R
With CS
respond to the U/D ¯ and INC
transitions on INC
wiper (depending on the state of the U/D ¯ input and
five-bit counter). The wiper, when at either end
terminal, acts like its mechanical equivalent and does
not move beyond the last position. The value of the
counter is stored in nonvolatile memory whenever CS
transitions HIGH while the INC
When the device is powered-down, the last stored
wiper counter position is maintained in the nonvolatile
memory. When power is restored, the contents of the
memory are recalled and the counter is set to the
value stored.
With INC
powered down without storing the current wiper
position in nonvolatile memory. This allows the system
to always power up to a preset value stored in
nonvolatile memory.
H
¯¯¯ set low, the device may be de-selected and
¯¯ set LOW, the device is selected and will
¯¯¯ wil increment or decrement the
¯¯¯ inputs. HIGH to LOW
¯¯¯ input is also HIGH.
CAT5127, CAT5129
Doc. No. 2127 Rev. A
¯¯