CAT5261_13 Datasheet, PDF (4/14 Pages) ON Semiconductor – Dual Digital Potentiometer (POT)

CAT5261
SERIAL BUS PROTOCOL
The CAT5261 supports the SPI bus data transmission
protocol. The synchronous Serial Peripheral Interface (SPI)
helps the CAT5261 to interface directly with many of
today’s popular microcontrollers. The CAT5261 contains an
8-bit instruction register. The instruction set and the
operation codes are detailed in the Instruction Set Table 13
on page 9.
DEVICE OPERATION
The CAT5261 is two resistor arrays integrated with an SPI
serial interface logic, two 8-bit wiper control registers and
eight 8-bit, non-volatile memory data registers. Each
resistor array contains 255 separate resistive elements
connected in series. The physical ends of each array are
equivalent to the fixed terminals of a mechanical
potentiometer (R_H and R_L). R_H and R_L are symmetrical and
may be interchanged. The tap positions between and at the
ends of the series resistors are connected to the output wiper
terminals (R_W) by a After the device is selected with CS
going low the first byte will be received. The part is accessed
via the SI pin, with data being clocked in on the rising edge
of SCK. The first byte contains one of the six op-codes that
define the operation to be performed.
CMOS transistor switch. Only one tap point for each
potentiometer is connected to its wiper terminal at a time and
is determined by the value of the wiper control register. Data
can be read or written to the wiper control registers or the
non-volatile memory data registers via the SPI bus.
Additional instructions allows data to be transferred
between the wiper control registers and each respective
potentiometer’s non-volatile data registers. Also, the device
can be instructed to operate in an “increment/decrement”
mode.
Table 2. ABSOLUTE MAXIMUM RATINGS
Parameters
Ratings
Units
Temperature Under Bias
−55 to +125
C
Storage Temperature
−65 to +150
C
Voltage on Any Pin with Respect to Ground (Note 1)
V_CC with Respect to Ground
Package Power Dissipation Capability (T_A = 25C)
Lead Soldering Temperature (10 s)
−2.0 to +V_CC + 2.0
V
−0.2 to +7.0
V
1.0
W
300
C
Wiper Current
6
mA
Stresses exceeding Maximum Ratings may damage the device. Maximum Ratings are stress ratings only. Functional operation above the
Recommended Operating Conditions is not implied. Extended exposure to stresses above the Recommended Operating Conditions may affect
device reliability.
Table 3. RECOMMENDED OPERATING CONDITIONS
Parameters
V_CC
Industrial Temperature
Ratings
+2.5 to +6.0
−40 to +85
Units
V
C
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