CAT522 Datasheet, PDF (1/10 Pages) Catalyst Semiconductor – 8-Bit Dual Digital POT With Independent Reference Inputs

Advanced Information
CAT522
8-Bit Dual Digital POT With Independent Reference Inputs
FEATURES
s Buffered Outputs
s Output settings retained without power
s Independent Reference Inputs
s Output range includes both supply rails
s Programming voltage generated on-chip
s 2 independently addressable outputs
s Serial µP interface
s Single supply operation: 2.7V-5.5V
DESCRIPTION
The CAT522 is a dual 8-Bit Memory DAC designed as an
electronic replacement for mechanical potentiometers
and trim pots. Intended for final calibration of products
such as camcorders, fax machines and cellular tele-
phones on automated high volume production lines and
systems capable of self calibration, it is also well suited
for applications were equipment requiring periodic ad-
justment is either difficult to access or located in a
hazardous environment.
The CAT522 offers 2 independently programmable DACs
each having its own reference inputs and each capable
of rail to rail output swing. Outputs are buffered by rail
to rail OP AMPS Output settings, stored in non-volatile
EEPROM memory, are not lost when the device is
powered down and are automatically reinstated when
power is returned. Each output can be dithered to test
new output values without effecting the stored settings
FUNCTIONAL DIAGRAM
VDD
1
RDY/BSY
3
SERIAL DATA OUTPUT
6
DO
PROG
7
PROGRAM
CONTROL
CLK
2
4
CS
DI
5
DATA
CONTROLLER
H.V.
CHARGE
PUMP
EEPROM
LATCH
DAC 1
14
VREF H1
+
–
12
VOUT 1
9
VREF L1
EEPROM
LATCH
DAC 2
13
VREF H2
+
–
11
VOUT 2
10
VREF L2
CAT522
8
GND
APPLICATIONS
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.
and stored settings can be read back without disturbing
the DAC’s output.
Control of the CAT522 is accomplished with a simple 3
wire serial interface. A Chip Select pin allows several
CAT522's to share a common serial interface and com-
munications back to the host controller is via a single
serial data line thanks to the CAT522’s Tri-Stated Data
Output pin. A RDY/BSY output working in concert with
an internal low voltage detector signals proper operation
of EEPROM Erase/Write cycle.
The CAT522 operates from a single 3–5 volt power
supply. The high voltage required for EEPROM Erase/
Write operations is generated on-chip.
The CAT522 is available in the 0°C to 70°C Commercial
and –40°C to +85°C Industrial operating temperature
ranges and offered in 14-pin plastic DIP and Surface
mount packages.
PIN CONFIGURATION
DIP Package (P)
SOIC Package (J)
VDD
CLK
RDY/BSY
CS
DI
DO
PROG
1
14
2
13
3
12
4
11
CAT522
5
10
6
9
7
8
VREF ^H1
VREF ^H2
VDD
CLK
VOUT1
RDY/BSY
VOUT2
CS
VREF ^L2
DI
VREF ^L1
DO
GND
PROG
1
14
2
13
3
12
4
11
CAT522
5
10
6
9
7
8
VREF ^H1
VREF ^H2
VOUT1
VOUT2
VREF ^L2
VREF ^L1
GND
© 2000 by Catalyst Semiconductor, Inc.
Characteristics subject to change without notice
1