ISL23445 Intersil Corporation, ISL23445 Datasheet - Page 17

• Manufacturer Part Number: ISL23445
• Description: Low Voltage Digitally Controlled Potentiometer
• Manufacturer: Intersil Corporation

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transition from a very low impedance “make” to a much higher
impedance “break” within a short period of time (<1µs). There
are several code transitions such as 0Fh to 10h, 1Fh to 20h,...,
EFh to FFh, which have higher transient glitch. Note, that all
switching transients will settle well within the settling time as
stated in the datasheet. A small capacitor can be added
externally to reduce the amplitude of these voltage transients,
but that will also reduce the useful bandwidth of the circuit, thus,
this may not be a good solution for some applications. It may be
a good idea, in this case, to use fast amplifiers in a signal chain
for fast recovery.
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SDO
SCK
SDI
CS
µC
SDO 0
SDO 1
SDO 2
MOSI
MISO
SCK
SCK
SDI
CS
CS
INSTRUCTION
1
17
2
CS
SCK
SDI
WR
DCP0
FIGURE 30. DAISY CHAIN WRITE SEQUENCE OF N = 3 DCP
3
16 CLKLS
SDO
D C P2
4
FIGURE 31. TWO BYTE READ INSTRUCTION
FIGURE 29. DAISY CHAIN CONFIGURATION
5
ADDR
CS
SCK
SDI
6
ISL23445
DCP1
7
WR
WR
SDO
16 CLKS
V
It is recommended to keep V
normal operation. In a case where turning V
necessary, it is recommended to ground the V
ISL23445. Grounding the V
not affect other devices on the same bus. It is good practice to put
a 1µF capacitor in parallel with 0.1µF decoupling capacitor close to
the V
V
It is recommended to put a 1µF capacitor in parallel with 0.1µF
decoupling capacitor close to the V
8
D C P1
D C P2
N DCP IN A CHAIN
LOGIC
CC
LOGIC
Requirements and Placement
9
Requirements
pin.
CS
SCK
SDI
10
DCP2
11
SDO
WR
WR
WR
DATA OUT
DATA IN
16 CLKS
12
D C P2
D C P1
D C P0
LOGIC
LOGIC
13
pin or both V
CC
powered all the time during
14
pin.
15
LOGIC
CS
SCK
SDI
LOGIC
DCP(N-1)
LOGIC
16
OFF is
and V
SDO
pin of the
June 21, 2011
CC
FN7874.0
does
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