CAT513 Catalyst Semiconductor, CAT513 Datasheet - Page 7

• Manufacturer Part Number: CAT513
• Description: 8-Bit Dual Digital POT
• Manufacturer: Catalyst Semiconductor

this value is the same as that which had been there
previously no change in the DAC’s output is noticed.
Had the value held in the control register been different
from that stored in EEPROM then a change would occur
at the read cycle’s conclusion.
TEMPORARILY CHANGE OUTPUT
The CAT513 allows temporary changes in DAC’s output
to be made without disturbing the settings retained in
EEPROM memory. This feature is particularly useful
when testing for a new output setting and allows for user
adjustment of preset or default values without losing the
original factory settings.
Figure 3 shows the control and data signals needed to
effect a temporary output change. DAC settings may be
changed as many times as required and can be made to
any of the four DACs in any order or sequence. The
temporary setting(s) remain in effect long as CS remains
high. When CS returns low all four DACs will return to the
output values stored in EEPROM memory.
When it is desired to save a new setting acquired using
APPLICATION CIRCUITS
CONTROL
& DATA
Advance Information
CONTROL
& DATA
+5V
+5V
V DD
OPT 504
GND
V DD
OPT 504
GND
CAT513
CAT513
Buffered DAC Output
V i
V
V
V
V
REF
REF
REF
REF
H
L
H
L
V
For R =
V
R
OUT
OUT
i
i R F
V
=
= 2V
OUT
V DAC
DAC
–
+
+15V
-15V
–
+
= V
+15V
-15V
(
DAC
-V
R + i
OP 07
R
OP 07
i
F
R i
R F
) -V
Bipolar DAC Output
i
V OUT
R F
V OUT
7
MSB
1111
1000
0111
0000
0000
DAC INPUT
this feature, the new value must be reloaded into the
DAC control register prior to programming. This is be-
cause the CAT513’s internal control circuitry discards
the new data from the programming register two clock
cycles after receiving it (after reception is complete) if no
PROG signal is received.
Figure 3. Temporary Change in Output
OUTPUT
CONTROL
& DATA
PROG
DAC
DO
CS
DI
1111
0000
1111
0001
0000
LSB
t
o
—— (.98 V
—— (.98 V
—— (.98 V
—— (.98 V
—— (.98 V
V
V
V
255
255
128
255
127
255
255
255
FS
1
0
DAC
ZERO
1
1
+5V
= 0.99 V
2
A0
= ——— (V
V DD
OPT 504
GND
CAT513
= 0.01 V
3
CODE
A1
255
REF
REF
REF
REF
REF
NON-VOLATILE
Amplified DAC Output
4
DAC OUTPUT
DAC VALUE
CURRENT
REF
D0
D0
5
) + .01 V
) + .01 V
) + .01 V
) + .01 V
) + .01 V
D1
D1
REF
V
V
6
REF
FS
REF
CURRENT DAC DATA
NEW DAC DATA
D2
D2
7
- V
H
L
D3
D3
REF
REF
REF
REF
REF
ZERO
8
D4
D4
9
= .990 V
= .502 V
= .498 V
= .014 V
= .010 V
D5
D5
V
10
R
) + V
OUT
i
D6
D6
11
Doc. No. ___________ 3/01 M-1
ZERO
D7
REF
D7
REF
REF
REF
REF
= (1 + –––) V
12
DAC VALUE
VOLATILE
–
+
NEW
+15V
-15V
R F
R I
V
V
V
V
V
V
R = R
OUT
OUT
OUT
OUT
OUT
ANALOG
OUTPUT
REF
N
I
R
OP 07
F
N+1 N+2
NON-VOLATILE
DAC
DAC VALUE
= +4.90V
= +0.02V
= -0.02V
= -4.86V
= -4.90V
CURRENT
= 5V
F
V OUT