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 µP interface
■ Single supply operation: 2.7V-5.5V
■ Setting read-back without effecting outputs
DESCRIPTION
stated when power is returned. Each wiper can be
dithered to 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
calibration of products such as camcorders, fax ma-
chines and cellular telephones on automated high vol-
ume production lines and systems capable of self cali-
bration, it is also well suited for applications were equip-
ment requiring periodic adjustment is either difficult to
access or located in a hazardous environment.
Control of the CAT525 is accomplished with a simple 3
wire serial interface. A Chip Select pin allows several
CAT525's to share a common serial interface and
communicationsbacktothehostcontrollerisviaasingle
serial data line thanks to the CAT525’s Tri-Stated Data
Output pin. A RDY/BSY output working in concert with
aninternallowvoltagedetectorsignalsproperoperation
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
device is powered down and are automatically rein-
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
H1
V
V
H3
V
REF
REF
H2
H4
REF
REF
2
1
20
19
SOIC Package (J)
DIP Package (P)
5
9
RDY/BSY
18
17
16
15
+
–
H3
H4
H2
20
19
18
17
16
15
V
1
2
3
4
1
2
3
4
5
V
V
V
V
H3
H4
OUT
H2
20
19
18
17
16
15
REF
REF
1
2
3
4
5
V
V
V
V
PROGRAM
CONTROL
REF
REF
PROG
H1
V
REF
V
H1
V
REF
REF
V
REF
+
–
V
OUT
1
D
D
OUT
1
D
D
OUT
4
6
NVRAM
V
2
3
CLK
CS
CLK
V
2
3
OUT
CLK
OUT
+
–
DATA
CONTROLLER
V
OUT
V
V
RDY/BSY
CS
V
V
OUT
RDY/BSY
CS
OUT
7
4
4
6
7
OUT
6
7
OUT
+
–
V
CAT525
OUT
CAT525
L4
L3
14
13
12
11
V
V
DI
DO
L4
L3
REF
7K
(ea)
14
13
12
11
V
V
DI
DO
REF
8
9
REF
H.V.
CHARGE
PUMP
8
9
SERIAL
DATA
OUTPUT
REGISTER
REF
8
DO
V
L2
L1
PROG
GND
V
L2
L1
REF
REF
PROG
GND
REF
REF
10
V
11
12
V
13
14
V
CAT525
10
V
L2
L4
REF
REF
V
L1
V
L3
REF
REF
© 2001 by Catalyst Semiconductor, Inc.
Characteristics subject to change without notice
Doc. No. 25078-00 4/01-A M-1
1