CAT525_0711 Datasheet, PDF (1/16 Pages) Catalyst Semiconductor – Quad Digitally Programmable Potentiometer (DPP™) with 256 Taps and Microwire Interface

CAT525
Quad Digitally Programmable Potentiometer (DPP™) with
256 Taps and Microwire Interface
FEATURES
„ Four 8-bit DPPs configured as programmable
voltage sources in DAC-like applications
„ Independent reference inputs
„ Buffered wiper outputs
„ Non-volatile NVRAM memory wiper storage
„ Output voltage range includes both supply rails
„ 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
For Ordering Information details, see page 15.
APPLICATIONS
„ Automated product calibration
„ Remote control adjustment of equipment
„ Offset, gain and zero adjustments in self-
calibrating and adaptive control systems
„ Tamper-proof calibrations
„ DAC (with memory) substitute
PIN CONFIGURATION
PDIP 20-Lead (L)
SOIC 20-Lead (W)
V_REFH2 1
20 V_REFH3
V_REFH1 2
19 V_REFH4
V_DD 3
18 V_OUT1
CLK 4
17 V_OUT2
RDY/¯B¯S¯Y¯ 5
16 V_OUT3
CAT525
CS 6
15 V_OUT4
DI 7
14 V_REFL4
DO 8
13 V_REFL3
PROG 9
12 V_REFL2
GND 10
11 V_REFL1
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
3wire, 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/¯B¯S¯Y¯
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 com–
mercial and -40°C to 85°C industrial operating
temperature ranges and offered in 20-pin plastic DIP
and surface mount packages.
© Catalyst Semiconductor, Inc.
1
Characteristics subject to change without notice
Doc. No. MD-2001 Rev. H