ISL22317 Datasheet, PDF (10/15 Pages) Intersil Corporation – Precision Single Digitally Controlled Potentiometer (XDCP™)

ISL22317
Typical Performance Curves (Continued)
40
40
30
20
V_CC = 2.7V
30
V_CC = 2.7V
20
10
V_CC = 5.5V
0
15
35
55
75
95
115
TAP POSITION (DECIMAL)
FIGURE 17. TC FOR RHEOSTAT MODE (10k/50k/100k) IN ppm
[R_REF 2ppm/°C]
10
V_CC = 5.5V
0
15
35
55
75
95
115
TAP POSITION (DECIMAL)
FIGURE 18. TC FOR VOLTAGE DIVIDER MODE (10k/50k/100k)
IN ppm [R_REF 10ppm/°C]
800
V_CC = 5.5V
600
400
V_CC = 2.7V
200
0
-40
0
40
80
120
TEMPERATURE (°C)
FIGURE 19. STANDBY I_CC vs TEMPERATURE
Pin Description
Potentiometers Pins
RH AND RL
The high (RH) and low (RL) terminals of the ISL22317 are
equivalent to the fixed terminals of a mechanical
potentiometer. RH and RL are referenced to the relative
position of the wiper and the voltage potential on the
terminals. With WR set to 127 decimal, the wiper will be
closest to RH. With the WR set to 0, the wiper is closest to
RL. The voltage potential on the RH terminal must be higher
than voltage potential on RL terminal.
RW
RW 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 WR register.
REF_A, REF_B
REF_A and REF_B are pins to connect an external resistor.
If application is required to connect RL terminal to GND, then
the REF_B pin should also be connected to GND.
10
100
80
T = +125°C
60
V_CC = 5.5V
T = +25°C
40
T = -40°C
20
0
0
20
40
60
80
100
120
TAP POSITION (DECIMAL)
FIGURE 20. WIPER RESISTANCE vs TAP POSITION WHEN
PRECISION IS OFF
Warning! Do not connect REF_A to GND under any
circumstances. That may damage the ISL22317.
Bus Interface Pins
SERIAL DATA INPUT/OUTPUT (SDA)
The SDA is a bidirectional serial data input/output pin for I²C
interface. It receives device address, operation code, wiper
address and data from an I²C external master device at the
rising edge of the serial clock SCL, and it shifts out data after
each falling edge of the serial clock.
SDA requires an external pull-up resistor, since it is an open
drain input/output.
SERIAL CLOCK (SCL)
This input is the serial clock of the I²C serial interface.
DEVICE ADDRESS (A1)
The address input is used to set the A1 bit of the 7-bit I2C
interface slave address, see Table 3. A match in the slave
address serial data stream must match with the Address
input pins in order to initiate communication with the
FN6912.0
May 26, 2009