CAT525_04 Datasheet, PDF (1/12 Pages) Catalyst Semiconductor – Configured Digitally Programmable Potentiometer

CAT525
ALOGEN ^FR
Configured Digitally Programmable Potentiometer (DPP™):
Programmable Voltage Applications
LEA _{D F REETM}
FEATURES
s Four 8-bit DPPs configured as programmable
voltage sources in DAC-like applications
s Independent reference inputs
s Buffered wiper outputs
s Single supply operation: 2.7V - 5.5V
s Setting read-back without effecting outputs
APPLICATIONS
s Non-volatile NVRAM memory wiper storage
s Output voltage range includes both supply rails
s 4 independently addressable buffered
output wipers
s 1 LSB accuracy, high resolution
s Serial Microwire-like interface
s Automated product calibration
s Remote control adjustment of equipment
s Offset, gain and zero adjustments in
self-calibrating and adaptive control systems
s Tamper-proof calibrations
s DAC (with memory) substitute
DESCRIPTION
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 machines
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.
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 reinstated
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.
Control of the CAT525 is accomplished with a simple 3-
wire, 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 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
VREF _H1 VREF _H3
VREF _H2
VREF _H4
2 1 20 19
RDY/BSY
5
+
PROG
9
PROGRAM
–
CONTROL
CLK
4
6
CS
7
DI
DATA
CONTROLLER
WIPER
CONTROL
REGISTERS
AND
NVRAM
H.V.
CHARGE
PUMP
SERIAL
DATA
OUTPUT
REGISTER
+
–
+
–
+
–
24kΩ
(ea)
CAT525
11 12 13 14
VREFL2 VREFL4
VREFL1 VREFL3
© 2004 by Catalyst Semiconductor, Inc.
Characteristics subject to change without notice
18
VOUT1
17
VOUT2
16
VOUT3
15
VOUT4
8
DO
PIN CONFIGURATION
DIP Package (P, L)
VREF _H2
VREF _H1
VDD
CLK
RDY/BSY
CS
DI
DO
PROG
GND
1
20
2
19
3
18
4
17
5
16
6
15
CAT525
7
14
8
13
9
12
10
11
VREF _H3
VREF _H4
VOUT1
VOUT2
VOUT3
VOUT4
VREFL4
VREF _L3
VREF _L2
VREF _L1
SOIC Package (J, W)
VREF _H2
VREF _H1
VDD
CLK
RDY/BSY
CS
DI
DO
PROG
GND
1
20
2
19
3
18
4
17
5
16
6
15
CAT525
7
14
8
13
9
12
10
11
VREF _H3
VREF _H4
VOUT1
VOUT2
VOUT3
VOUT4
VREFL4
VREF _L3
VREF _L2
VREF _L1
Doc. No. 2001, Rev. E
1