CAT5409 Datasheet, PDF (2/17 Pages) Catalyst Semiconductor – Quad Digitally Programmable Potentiometers (DPPTM) with 64 Taps and 2-wire Interface

CAT5409
PIN DESCRIPTION
Pin
Pin
Pin
(TSSOP) (SOIC) (BGA) Name
19
1
C1 VCC
20
2
B1
RL0
21
3
C2
RH0
22
4
A1
RW0
23
5
A2
A2
24
6
B2
WP
1
7
B3 SDA
2
8
A3
A1
3
9
A4
RL1
4
10
C3
RH1
5
11
B4
RW1
6
12
C4 GND
7
13
D4
NC
8
14
E4
RW2
9
15
D3
RH2
10
16
F4
RL2
11
17
F3 SCL
12
18
E3
A3
13
19
D1
NC
14
20
F2
A0
15
21
F1
RW3
16
22
D2
RH3
17
23
E1
RL3
18
24
E2
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
Wiper Terminal for
Potentiometer 2
High Reference Terminal
for Potentiometer 2
Low Reference Terminal
for Potentiometer 2
Bus Serial Clock
Device Address
No Connect
Device Address, LSB
Wiper Terminal for Potentiometer 3
High Reference Terminal
for Potentiometer 3
Low Reference Terminal
for Potentiometer 3
No Connect
PIN DESCRIPTIONS
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 ad-
dressing 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.
RH, RL: Resistor End Points
The four sets of RH and RL pins are equivalent to
the terminal connections on a mechanical potenti-
ometer.
RW: Wiper
The four RW 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 7 for more details.
DEVICE OPERATION
The CAT5409 is four resistor arrays integrated with 2-
wire 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 (RH and RL). RH and RL
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 (RW) 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 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.
Document No. 2010, Rev. I
2