CAT5409_13 Datasheet, PDF (3/15 Pages) ON Semiconductor – Quad Digital Potentiometer (POT)

CAT5409
PIN DESCRIPTIONS
Table 1. PIN DESCRIPTIONS
Pin#
(TSSOP)
Pin#
(SOIC)
Name
Function
19
1
V_CC
Supply Voltage
20
2
R_L0
Low Reference Terminal
for Potentiometer 0
21
3
R_H0
High Reference Terminal
for Potentiometer 0
22
4
R_W0
Wiper Terminal for
Potentiometer 0
23
5
A2
Device Address
24
6
WP
Write Protection
1
7
SDA Serial Data Input/Output
2
8
A1
Device Address
3
9
R_L1
Low Reference Terminal
for Potentiometer 1
4
10
R_H1
High Reference Terminal
for Potentiometer 1
5
11
R_W1
Wiper Terminal for
Potentiometer 1
6
12
GND Ground
7
13
NC
No Connect
8
14
R_W2
Wiper Terminal for
Potentiometer 2
9
15
R_H2
High Reference Terminal
for Potentiometer 2
10
16
R_L2
Low Reference Terminal
for Potentiometer 2
11
17
SCL Bus Serial Clock
12
18
A3
Device Address
13
19
NC
No Connect
14
20
A0
Device Address, LSB
15
21
R_W3
Wiper Terminal for
Potentiometer 3
16
22
R_H3
High Reference Terminal
for Potentiometer 3
17
23
R_L3
Low Reference Terminal
for Potentiometer 3
18
24
NC
No Connect
SCL: Serial Clock
The CAT5409 serial clock input pin is used to clock all
data transfers into or out of the device.
SDA: Serial Data
The CAT5409 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-Ored 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 CAT5409.
R_H, R_L: Resistor End Points
The four sets of R_H and R_L pins are equivalent to the
terminal connections on a mechanical potentiometer.
R_W: Wiper
The four R_W pins are equivalent to the wiper terminal of
a mechanical potentiometer.
WP: Write Protect Input
The WP 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 Write Protection on
page 8 for more details.
DEVICE OPERATION
The CAT5409 is four resistor arrays integrated with I²C
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 I²C 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.
http://onsemi.com
3