CAT5419WI-25 Datasheet, PDF (2/16 Pages) ON Semiconductor – Dual Digitally Programmable Potentiometers with 64 Taps and 2-wire Interface

CAT5419
PIN DESCRIPTIONS
SCL: Serial Clock
The CAT5419 serial clock input pin is used to
clock all data transfers into or out of the device.
SDA: Serial Data
The CAT5419 bidirectional serial data pin is used
to transfer data into and out of the device. The
SDA pin is an open drain output and can be wire-
OR'd with the other open drain or open collector
outputs.
A0, A1, A2, A3: Device Address Inputs
These inputs set the device address when
addressing multiple devices. A total of sixteen
devices can be addressed on a single bus. A
match in the slave address must be made with the
address input in order to initiate communication
with the CAT5419.
R_H, R_L: Resistor End Points
The R_H and R_L pins are equivalent to the terminal
connections on a mechanical potentiometer.
R_W: Wiper
The R_W pins are equivalent to the wiper terminal of
a mechanical potentiometer.
¯W¯P¯: _{Write Protect Input}
The ^{¯W¯P¯} pin when tied low prevents non-volatile
writes to the data registers (change of wiper
control register is allowed) and when tied high or
left floating normal read/write operations are
allowed. See page 7, Write Protection for more
details.
Pin
SOIC
1
Pin
TSSOP
19
2
20
3
21
4
22
5
23
6
24
7
1
8
2
9
3
10
4
11
5
12
6
13
7
14
8
15
9
16
10
17
11
18
12
19
13
20
14
21
15
22
16
23
17
24
18
Name
V_CC
R_L0
R_H0
R_W0
A2
¯W¯P¯
SDA
A1
R_L1
R_H1
R_W1
GND
NC
NC
NC
NC
SCL
A3
NC
A0
NC
NC
NC
NC
Function
Supply Voltage
Low Reference Terminal for
Potentiometer 0
High Reference Terminal for
Potentiometer 0
Wiper Terminal for
Potentiometer 0
Device Address
Write Protection
Serial Data Input/Output
Device Address
Low Reference Terminal for
Potentiometer 1
High Reference Terminal for
Potentiometer 1
Wiper Terminal for
Potentiometer 1
Ground
No Connect
No Connect
No Connect
No Connect
Bus Serial Clock
Device Address
No Connect
Device Address, LSB
No Connect
No Connect
No Connect
No Connect
DEVICE OPERATION
The CAT5419 is two resistor arrays integrated with 2wire serial interface logic, four 6-bit wiper control registers
and sixteen 6-bit, non-volatile memory data registers. Each resistor array contains 63 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 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 2-wire bus. Additional instructions allow 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.
Doc. No. MD-2115 Rev. I
2
2008 SCILLC. All rights reserved.
Characteristics subject to change without notice