CAT525
Configured Digitally Programmable Potentiometer (DPP™): Programmable Voltage Applications
APPLICATIONS
FEATURES
■ Automated product calibration
■ Four 8-bit DPPs configured as programmable
voltage sources in DAC-like applications
■ Remote control adjustment of equipment
■ Independent reference inputs
■ Offset, gain and zero adjustments in
self-calibrating and adaptive control systems
■ Buffered wiper outputs
■ Tamper-proof calibrations
■ Non-volatile NVRAM memory wiper storage
■ Output voltage range includes both supply rails
■ DAC (with memory) substitute
■ 4 independently addressable buffered
output wipers
■ 1 LSB accuracy, high resolution
■ Serial Microwire-like interface
■ Single supply operation: 2.7V-5.5V
■ Setting read-back without effecting outputs
DESCRIPTION
test new output values without effecting the stored
settings and stored settings can be read back without
disturbing the DPP’s output.
The CAT525 is a quad 8-bit digitally programmable
potentiometer (DPP™) configured for programmable
voltage and DAC-like applications. Intended for final
calibrationofproductssuchascamcorders,faxmachines
and cellular telephones on automated high volume
production lines and systems capable of self calibration,
it is also well suited for applications were equipment
requiring periodic adjustment is either difficult to access
or located in a hazardous environment.
Control of the CAT525 is accomplished with a simple 3
Microwire-like serial interface. A Chip Select pin allows
several CAT525's to share a common serial interface
and communications back to the host controller is via a
single serial data line thanks to the CAT525’s Tri-Stated
Data Output pin. A RDY/BSY output working in concert
with an internal low voltage detector signals proper
operation of non-volatile NVRAM Memory Erase/Write
cycle.
The CAT525 offers four independently programmable
DPPs each having its own reference inputs and each
capable of rail to rail output swing. The wipers are
buffered by rail to rail op amps. Wiper settings, stored in
non-volatile NVRAM memory, are not lost when the
deviceispowereddownandareautomaticallyreinstated
when power is returned. Each wiper can be dithered to
The CAT525 is available in the 0°C to 70°C commercial
and –40°C to 85°C industrial operating temperature
ranges and offered in 20-pin plastic DIP and surface
mount packages.
FUNCTIONAL DIAGRAM
PIN CONFIGURATION
V
V
REF H3
REF H1
V
V
REF H4
REF H2
2
1
20
19
SOIC Package (J)
DIP Package (P)
5
9
RDY/BSY
V
V
V
V
REFH2
1
2
3
4
5
20
19
18
17
16
15
18
17
16
15
REFH3
V
+
–
V
V
V
REFH2
1
2
3
4
5
20
19
18
17
16
15
14
13
12
11
REFH3
V
OUT1
PROGRAM
CONTROL
PROG
V
REFH4
REFH1
V
REFH4
REFH1
WIPER
CONTROL
REGISTERS
AND
+
–
V
V
OUT1
DD
V
OUT2
OUT1
DD
V
CLK
4
6
NVRAM
V
OUT2
CLK
CLK
CS
DI
OUT2
+
–
DATA
CONTROLLER
V
V
OUT3
OUT3
RDY/BSY
CS
RDY/BSY
CS
V
OUT3
V
OUT4
6
7
7
V
OUT4
6
CAT525
CAT525
+
–
V
OUT4
14
13
12
11
V
REFL4
DI
DO
7
V
DI
DO
REFL4
28kΩ
(ea)
8
9
V
REFL3
8
V
REFL3
H.V.
CHARGE
PUMP
SERIAL
DATA
OUTPUT
REGISTER
8
PROG
GND
V
DO
9
REFL2
V
REFL1
PROG
GND
V
REFL2
V
REFL1
10
10
11
12
V
13
14
V
CAT525
REFL2
REFL4
V
V
REFL1
REFL3
© 2001 by Catalyst Semiconductor, Inc.
Characteristics subject to change without notice
Doc. No. 2001, Rev. A
1