CAT522
Configured Digitally Programmable Potentiometer (DPP™):
Programmable Voltage Applications
H
GEN
FR
ALO
EE
LE
FEATURES
s
Two 8-bit DPPs configured as programmable
A
D
F
R
E
E
TM
APPLICATIONS
s
Automated product calibration.
s
Remote control adjustment of equipment
s
Offset, gain and zero adjustments in self-
voltage sources in DAC-like applications
s
Independent reference inputs
s
Non-volatile NVRAM memory wiper storage
s
Output voltage range includes both supply rails
s
2 independently addressable buffered
calibrating and adaptive control systems.
s
Tamper-proof calibrations.
s
DAC (with memory) substitute.
output wipers
s
1 LSB accuracy, high resolution
s
Serial Microwire-like interface
s
Single supply operation: 2.7V - 5.5V
s
Setting read-back without effecting outputs
DESCRIPTION
The CAT522 is a dual, 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, it is also well suited for
self-calibrating systems and for applications where
equipment which requires periodic adjustment is either
difficult to access or in a hazardous environment.
The CAT522 offers two 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 opamps. 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
FUNCTIONAL DIAGRAM
RDY/BSY
V
DD
VREFH1 VREFH2
14
13
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 CAT522 is controlled with a simple 3-wire, microwire-
like serial interface. A Chip Select pin allows several
devices to share a common serial interface.
Communication back to the host controller is via a single
serial data line thanks to the CAT522 Tri-Stated Data
Output pin. A RDY/BSY output working in concert with
an internal low voltage detector signals proper operation
of the non-volatile NVRAM memory Erase/Write cycle.
The CAT522 is available in the 0°C to 70°C commercial
and -40°C to 85°C industrial operating temperature
ranges. Both 14-pin plastic DIP and surface mount
packages are available.
PIN CONFIGURATION
DIP Package (P, L)
VDD
CLK
1
2
3
4
5
6
7
CAT522
SOIC Package (J, W)
VDD
CLK
1
2
3
4
5
6
7
CAT522
3
1
PROG
7
PROGRAM
CONTROL
14
13
12
11
10
9
8
VREFH1
VREFH2
14
13
12
11
10
9
8
VREFH1
VREFH2
VOUT1
VOUT2
VREFL2
VREFL1
GND
DI
5
WIPER
CONTROL
REGISTERS
AND
NVRAM
+
24KΩ
11
V
OUT2
RDY/BSY
CS
CLK
2
SERIAL
CONTROL
VOUT1 RDY/BSY
VOUT2
VREFL2
VREFL1
GND
CS
DI
DO
PROG
CS
4
24kΩ
+
12
V
OUT1
DI
DO
SERIAL
DATA
OUTPUT
REGISTER
6
DO
PROG
CAT522
8
GND
9
10
VREFL1 VREFL2
© 2004 by Catalyst Semiconductor, Inc.
Characteristics subject to change without notice
1
Doc. No. 2004, Rev. E
CAT522
ABSOLUTE MAXIMUM RATINGS
Supply Voltage*
V
DD
to GND ...................................... -0.5V to +7V
Inputs
CLK to GND ............................ -0.5V to V
DD
+0.5V
CS to GND .............................. -0.5V to V
DD
+0.5V
DI to GND ............................... -0.5V to V
DD
+0.5V
RDY/BSY to GND ................... -0.5V to V
DD
+0.5V
PROG to GND ........................ -0.5V to V
DD
+0.5V
V
REF
H to GND ........................ -0.5V to V
DD
+0.5V
V
REF
L to GND ......................... -0.5V to V
DD
+0.5V
Outputs
D
0
to GND ............................... -0.5V to V
DD
+0.5V
V
OUT
1– 4 to GND ................... -0.5V to V
DD
+0.5V
RELIABILITY CHARACTERISTICS
Symbol
V
ZAP(1)
I
LTH(1)(2)
Operating Ambient Temperature
Commercial (‘C’ or Blank suffix) ...... 0°C to +70°C
Industrial (‘I’ suffix) ........................ -40°C to +85°C
Junction Temperature ..................................... +150°C
Storage Temperature ........................ -65°C to +150°C
Lead Soldering (10 sec max) .......................... +300°C
* Stresses above those listed under Absolute Maximum Ratings
may cause permanent damage to the device. Absolute
Maximum Ratings are limited values applied individually while
other parameters are within specified operating conditions,
and functional operation at any of these conditions is NOT
implied. Device performance and reliability may be impaired by
exposure to absolute rating conditions for extended periods of
time.
Parameter
ESD Susceptibility
Latch-Up
Min
2000
100
Max
Units
Volts
mA
Test Method
MIL-STD-883, Test Method 3015
JEDEC Standard 17
NOTES:
1. This parameter is tested initially and after a design or process change that affects the parameter.
2. Latch-up protection is provided for stresses up to 100mA on address and data pins from –1V to V
CC
+ 1V.
POWER SUPPLY
Symbol Parameter
I
DD1
I
DD2
Supply Current (Read)
Supply Current (Write)
Conditions
Normal Operating
Programming, V
DD
= 5V
V
DD
= 3V
V
DD
Operating Voltage Range
Min
—
—
—
2.7
Typ
400
1600
1000
—
Max
600
2500
1600
5.5
Units
µA
µA
µA
V
LOGIC INPUTS
Symbol
I
IH
I
IL
V
IH
V
IL
Parameter
Input Leakage Current
Input Leakage Current
High Level Input Voltage
Low Level Input Voltage
Conditions
V
IN
= V
DD
V
IN
= 0V
Min
—
—
2
0
Typ
—
—
—
—
Max
10
-10
V
DD
0.8
Units
µA
µA
V
V
LOGIC OUTPUTS
Symbol Parameter
V
OH
V
IL
High Level Output Voltage
Low Level Output Voltage
Conditions
I
OH
= -40µA
I
OL
= 1 mA, V
DD
= +5V
I
OL
= 0.4 mA, V
DD
= +3V
Min
V
DD
-0.3
—
—
Typ
—
—
—
Max
—
0.4
0.4
Units
V
V
V
Doc. No. 2004, Rev. E
2
CAT522
POTENTIOMETER CHARACTERISTICS
V
DD
= +2.7V to +5.5V, V
REF
H = V
DD
, V
REF
L = 0V
, unless otherwise specified
Symbol
R
POT
Parameter
Potentiometer Resistance
R
POT
to R
POT
Match
Pot Resistance Tolerance
Voltage on V
REFH
pin
Voltage on V
REFL
pin
Resolution
INL
DNL
R
OUT
I
OUT
TC
RPOT
C
H
/C
L
Integral Linearity Error
Differential Linearity Error
Buffer Output Resistance
Buffer Output Current
TC of Pot Resistance
Potentiometer Capacitances
300
8/8
2.7
0V
0.4
0.5
0.25
1
0.5
10
3
—
Conditions
Min
Typ
24
+0.5
+1
+20
V
DD
V
DD
- 2.7
Max
Units
kΩ
%
%
V
V
%
LSB
LSB
Ω
mA
ppm/˚C
pF
AC ELECTRICAL CHARACTERISTICS:
V
DD
= +2.7V to +5.5V, V
REF
H = V
DD
, V
REF
L = 0V
, unless otherwise specified
Symbol
Digital
t
CSMIN
t
CSS
t
CSH
t
DIS
t
DIH
t
DO1
t
DO0
t
HZ
t
LZ
t
BUSY
t
PS
t
PROG
t
CLK
H
t
CLK
L
f
C
Minimum CS Low Time
CS Setup Time
CS Hold Time
DI Setup Time
DI Hold Time
Output Delay to 1
Output Delay to 0
Output Delay to High-Z
Output Delay to Low-Z
Erase/Write Cycle Time
PROG Setup Time
Minimum Pulse Width
Minimum CLK High Time
Minimum CLK Low Time
Clock Frequency
DPP Settling Time to 1 LSB
150
100
0
50
50
—
—
—
—
—
150
700
500
300
DC
—
—
—
—
—
—
—
—
—
400
400
4
—
—
—
—
—
3
6
—
—
—
—
—
150
150
—
—
5
—
—
—
—
1
10
10
ns
ns
ns
ns
ns
ns
ns
ns
ns
ms
ns
ns
ns
ns
MHz
µs
µs
Parameter
Conditions
Min
Typ
Max
Units
C
L
=100pF,
see note 1
Analog
t
DS
C
LOAD
= 10 pF, V
DD
= +5V
C
LOAD
= 10 pF, V
DD
= +3V
NOTES:
1. All timing measurements are defined at the point of signal crossing V
DD
/ 2.
2. These parameters are periodically sampled and are not 100% tested.
3
Doc. No. 2004, Rev. E
CAT522
A. C. TIMING DIAGRAM
to
1
2
3
4
5
t CLK H
CLK
t CSS
CS
t CLK L
t CSH
t CSMIN
t DIS
DI
t DIH
t LZ
DO
t DO0
t HZ
t DO1
PROG
t PS
t PROG
RDY/BSY
t BUSY
to
1
2
3
4
5
Doc. No. 2004, Rev. E
4
CAT522
PIN DESCRIPTION
Pin
1
2
3
4
5
6
7
8
9
10
11
12
13
14
DPP addressing is as follows:
Function
Power supply positive
Clock input pin
Ready/Busy output
Chip select
Serial data input pin
Serial data output pin
EEPROM Programming Enable
Input
Power supply ground
Minimum DPP 1 output voltage
Minimum DPP 2 output voltage
DPP 2 output
DPP 1 output
Maximum DPP 2 output voltage
Maximum DPP 1 output voltage
Name
V
DD
CLK
RDY/BSY
CS
DI
DO
PROG
GND
V
REFL1
V
REFL2
V
OUT2
V
OUT1
V
REFH2
V
REFH1
DPP OUTPUT
V
OUT1
V
OUT2
A0
0
1
A1
1
1
DEVICE OPERATION
The CAT522 is a dual 8-bit configured digitally
programmable potentiometer (DPP) whose outputs can
be programmed to any one of 256 individual voltage
steps. Once programmed, these output settings are
retained in non-volatile memory and will not be lost when
power is removed from the chip. Upon power up the
DPPs return to the settings stored in non-volatile memory.
Each DPP can be written to and read from independently
without effecting the output voltage during the read or
write cycle. Each output can also be adjusted without
altering the stored output setting, which is useful for
testing new output settings before storing them in
memory.
DIGITAL INTERFACE
The CAT522 employs a 3 wire serial, Microwire-like
control interface consisting of Clock (CLK), Chip Select
(CS) and Data In (DI) inputs. For all operations, address
and data are shifted in LSB first. In addition, all digital
data must be preceded by a logic “1” as a start bit. The
DPP address and data are clocked into the DI pin on the
clock’s rising edge. When sending multiple blocks of
information a minimum of two clock cycles is required
between the last block sent and the next start bit.
Multiple devices may share a common input data line by
selectively activating the CS control of the desired IC.
Data Outputs (DO) can also share a common line
because the DO pin is Tri-Stated and returns to a high
impedance when not in use.
CHIP SELECT
Chip Select (CS) enables and disables the CAT522’s
read and write operations. When CS is high data may be
read to or from the chip, and the Data Output (DO) pin is
active. Data loaded into the DPP control registers will
remain in effect until CS goes low. Bringing CS to a logic
low returns all DPP outputs to the settings stored in non-
volatile memory and switches DO to its high impedance
Tri-State mode.
Because CS functions like a reset the CS pin has been
desensitized with a 30 ns to 90 ns filter circuit to prevent
noise spikes from causing unwanted resets and the loss
of volatile data.
CLOCK
The CAT522’s clock controls both data flow in and out of
the IC and non-volatile memory cell programming. Serial
data is shifted into the DI pin and out of the DO pin on the
clock’s rising edge. While it is not necessary for the clock
to be running between data transfers, the clock must be
operating in order to write to non-volatile memory, even
though the data being saved may already be resident in
the DPP wiper control register.
No clock is necessary upon system power-up. The
CAT522’s internal power-on reset circuitry loads data
from non-volatile memory to the DPPs without using the
external clock.
5
Doc. No. 2004, Rev. E
嵌入式系统
京公网安备 11010802033920号
Copyright © 2005-2026 EEWORLD.com.cn, Inc. All rights reserved
电子工程世界
