ISL22449 Datasheet, PDF (8/12 Pages) Intersil Corporation – Quad Digitally Controlled Potentiometer

ISL22449
Typical Performance Curves (Continued)
1.00
Vcc = 2.7V
50k
0.50
0.00
-0.50
Vcc = 5.5V
10k
-1.00
-40 -20 0 20 40 60 80 100 120
TEMPERATURE (ºC)
FIGURE 7. END TO END R_TOTAL % CHANGE vs
TEMPERATURE
105
90 _10k
75
60
45
30
50k
15
0
16
36
56
76
96
TAP POSITION (DECIM AL)
FIGURE 8. TC FOR VOLTAGE DIVIDER MODE IN ppm
FIGURE 9. MIDSCALE GLITCH, CODE 80h TO 7Fh
Pin Description
Potentiometers Pins
RWi (i = 0, 1, 2, 3)
RWi is the wiper terminal and is equivalent to the movable
terminal of a mechanical potentiometer. The position of the
wiper within the array is determined by the WRi register.
SHDN
The SHDN pin forces the resistors to end-to-end open circuit
condition and shorts all RWs to GND. When SHDN is
returned to logic high, the previous latch settings put RWi at
the same resistance setting prior to shutdown. This pin is
logically OR’d with SHDN bit in ACR register. SPI interface is
still available in shutdown mode and all registers are
accessible. This pin must remain HIGH for normal operation.
8
FIGURE 10. LARGE SIGNAL SETTLING TIME
RW
FIGURE 11. DCP CONNECTION IN SHUTDOWN MODE
Bus Interface Pins
Serial Clock (SCK)
This is the serial clock input of the SPI serial interface.
FN6333.2
September 15, 2006