ISL23425_15 Datasheet, PDF (12/20 Pages) Intersil Corporation – Dual, 256-Tap, Low Voltage Digitally Contro Potentiometer (XDCP™)

ISL23425
Typical Performance Curves (Continued)
1V/DIV
0.2µs/DIV
CS RISING
0.5V/DIV
20µs/DIV
WIPER
V_CC
WIPER
FIGURE 21. WIPER LARGE SIGNAL SETTLING TIME
FIGURE 22. POWER-ON START-UP IN VOLTAGE DIVIDER MODE
CH1: RH TERMINAL
CH2: RW TERMINAL
0.5V/DIV, 0.2µs/DIV
-3dB FREQUENCY = 1.4MHz AT MIDDLE TAP
FIGURE 23. 10kΩ -3dB CUT OFF FREQUENCY
1.8
1.6
1.4
1.2
1.0
V_CC = 5.5V, V_LOGIC = 5.5V
0.8
0.6
0.4
V_CC = 1.7V, V_LOGIC = 1.2V
0.2
0
-40
-15
10
35
60
85
110
TEMPERATURE (°C)
FIGURE 24. STANDBY CURRENT vs TEMPERATURE
Functional Pin Descriptions
Potentiometers Pins
RHI AND RLI
The high (RHi, i = 0, 1) and low (RLi, i = 0, 1) terminals of the
ISL23425 are equivalent to the fixed terminals of a mechanical
potentiometer. RHi and RLi are referenced to the relative position
of the wiper and not the voltage potential on the terminals. With
WRi set to 255 decimal, the wiper will be closest to RHi, and with
the WRi set to 0, the wiper is closest to RLi.
RWI
RWi (i = 0, 1) is the wiper terminal, and it is equivalent to the
movable terminal of a mechanical potentiometer. The position of
the wiper within the array is determined by the WRi register.
Power Pins
V_CC
Power terminal for the potentiometer section analog power
source. Can be any value needed to support voltage range of DCP
pins, from 1.7V to 5.5V, independent of the V_LOGIC voltage.
Bus Interface Pins
SERIAL CLOCK (SCK)
This input is the serial clock of the SPI serial interface.
SERIAL DATA INPUT (SDI)
The SDI is a serial data input pin for SPI interface. It receives
operation code, wiper address and data from the SPI remote
host device. The data bits are shifted in at the rising edge of the
serial clock SCK, while the CS input is low.
12
FN7873.1
September 11, 2015