X93254_08 Datasheet, PDF (5/8 Pages) Intersil Corporation – Dual Digitally Controlled Potentiometers(XDCPs™)

X93254
AC Operating Specifications Over recommended operating conditions, unless otherwise stated. CS, INC, U/D, R_H and R_L are used to
refer to either CS₁ or CS₂, etc. (Continued)
SYMBOL
PARAMETER
MIN
(Note 7)
TYP
(Note 4)
MAX
(Note 7)
UNIT
t_CYC
t_R, t_F
(Note 5)
INC Cycle Time
INC input Rise and Fall Time
2
µs
500
µs
t_R V_CC V_CC Power-up Rate
(Note 5)
1
50
V/ms
t_WR
Store Cycle
5
10
ms
AC Timing
CS
t_CI
INC
t_CYC
t_IL
t_IH
t_IC
t_ID
t_DI
(STORE)
t_CPH
90% 90%
10%
t_F
t_R
U/D
Note: CS, INC, U/D, R_H and R_L are used to refer
to either CS₁ or CS₂, etc.
Power-up and Power-down Requirements
There are no restrictions on the power-up or power-down
conditions of V_CC and the voltages applied to the
potentiometer pins provided that V_CC is always more
positive than or equal to V_H and V_L, i.e., V_CC ≥ V_H,V_L. The
V_CC ramp rate specification is always in effect.
Pin Descriptions
In the text, CS, INC, U/D, R_H and R_L are used to refer to
either CS₁ or CS₂, etc. Note: These signals can be applied
independently or at the same time.
R_H and R_L
The R_H and R_L pins of the X93254 are equivalent to the
fixed terminals of a mechanical potentiometer. The minimum
voltage is V_SS and the maximum is V_CC. The terminology of
R_H and R_L references the relative position of the terminal in
relation to wiper movement direction selected by the U/D
input per potentiometer.
Up/Down (U/D)
The U/D input controls the direction of a single
potentiometer’s wiper movement and whether the counter is
incremented or decremented.
Increment (INC)
The INC input is negative-edge triggered. Toggling INC will
move the wiper and either increment or decrement the
corresponding potentiometer’s counter in the direction
indicated by the logic level on the corresponding
potentiometer’s U/D input.
Chip Select (CS)
A potentiometer is selected when the corresponding CS input
is LOW. Its current counter value is stored in nonvolatile
memory when the corresponding CS is returned HIGH while
the corresponding INC input is also HIGH. After the store
operation is complete, the affected potentiometer will be
placed in the low power standby mode until the potentiometer
is selected once again.
Principles of Operation
There are multiple sections for each potentiometer in the
X93254: an input control, a counter and decode section; the
nonvolatile memory; and a resistor array. Each input control
section operates just like an up/down counter. The output of
this counter is decoded to turn on a single electronic switch
connecting a point on the resistor array to the wiper output.
Under the proper conditions, the contents of the counter can
be stored in nonvolatile memory and retained for future use.
Each resistor array is comprised of 31 individual resistors
5
FN8186.1
February 4, 2008