ISL95710 Intersil Corporation, ISL95710 Datasheet - Page 7

• Manufacturer Part Number: ISL95710
• Description: 128 Taps Up/Down Interface
• Manufacturer: Intersil Corporation

power is restored, the contents of the memory are recalled
and the wiper is set to the value last stored.
Instructions and Programming
The INC, U/D and CS inputs control the movement of the
wiper along the resistor array. With CS set LOW the device
is selected and enabled to respond to the U/D and INC
inputs. HIGH to LOW transitions on INC will increment or
decrement (depending on the state of the U/D input) a seven
bit wiper counter. The output of this wiper counter is decoded
to select one of 128 wiper positions along the resistive array.
The value of the wiper counter is stored in nonvolatile
memory whenever CS transitions HIGH while the INC input
is also HIGH.
The system may select the ISL95710, move the wiper and
deselect the device without having to store the latest wiper
position in nonvolatile memory. After the wiper movement is
performed as described above and once the new position is
reached, the system must keep INC LOW while taking CS
HIGH. The new wiper position will be maintained until
changed by the system or until a power-up/down cycle
recalls the previously stored data.
7
ISL95710
This procedure allows the system to always power-up to a
preset value stored in nonvolatile memory; then during
system operation minor adjustments could be made. The
adjustments might be based on user preference, system
parameter changes due to temperature drift, etc.
The state of U/D may be changed while CS remains LOW.
This allows the host system to enable the device and then
move the wiper up and down until the proper trim is attained.
During initial power-up CS must go high along with or before
V
CC
CS
H
H
L
L
to avoid an accidental store generation.
INC
H
H
X
L
L
L
TABLE 1. MODE SELECTION
U/D
H
X
X
X
X
H
L
L
Wiper up
Wiper down
Store wiper position
Standby current
No store, return to standby
Standby
Wiper up one position
(not recommended)
Wiper down one position
(not recommended)
MODE
August 17, 2005
FN8240.2