LTC1294 LINER [Linear Technology], LTC1294 Datasheet - Page 25

• Manufacturer Part Number: LTC1294
• Description: Single Chip 12-Bit Data Acquisition System
• Manufacturer: LINER [Linear Technology]

22µF
A
A “Quick Look” Circuit for the LTC1294/6
Users can get a quick look at the function and timing of the
LTC1294/6 by using the following simple circuit (Figure
23). V
should be applied to the CH7 with respect to COM. A
TYPICAL
PPLICATI
V
IN
REF
+15V
is tied to V
CH0
CH1
CH2
CH3
CH4
CH5
CH6
CH7
COM
DGND
A
LTC1294
LT1027
PPLICATI
O
Rplat. = 1k AT 0°C – ROSEMOUNT #118MF
Figure 23. “Quick Look” Circuit for the LTC1294/6
12k*
1k*
U
CC
** 1% FILM RESISTOR
AGND
S
DV
AV
D
REF +
* TRW-IRC MAR-6 RESISTOR – 0.1%
REF
. D
CLK
OUT
D
CS
V
CC
CC
IN
–
–
IN
5V
I FOR ATIO
12.5k*
U
OUT
is tied high which means V
OSCILLOSCOPE
O
+
Rplat.
TO
U
10 F
Digitally Linearized Platinum RTD Signal Conditioner
W
S
500k
400°C TRIM
+
–
LT1101
A=10
A1
+15V
f
U
CLOCK IN
1MHz MAX
f/64
IN
+
–
LT1006
+15V
A2
ZERO°C TRIM
1 F
CLK
EN
Q1
Q2
Q3
Q4
RESET
V
Unipolar conversion is requested and the data is output
MSB first. CS is driven at 1/64 the clock rate by the CD4520
and D
pin can be viewed on an oscilloscope that is set up to
trigger on the falling edge of CS (Figure 24).
SS
3.92M**
30.1k**
500k
CD4520
OUT
RESET
LTC1293/LTC1294/LTC1296
V
CLK
outputs the data. The output data from the D
DD
Q4
Q3
Q2
Q1
EN
1k
+5V
LTC1293 F23
CH0
CH1
CH2
CH3
CH4
CH5
CH6
CH7
COM
DGND
LTC1294
D
CLK
AGND
OUT
DV
AV
D
REF +
REF
CS
CLK
OUT
D
CS
V
CC
CC
IN
Figure 24. Scope Trace of the
LTC1294/6 “Quick Look” Circuit
Showing A/D Output
101010101010 (AAA
–
–
NULL
BIT
VERTICAL: 5V/DIV
HORIZONTAL: 2 s/DIV
(B11)
MSB
TO/FROM
68HC11
PROCESSOR
LTC1293 TA03
22 F
TANTALUM
LSB
(B0)
HEX
FILLS
ZEROES
)
25
OUT