LTC2485 LINER [Linear Technology], LTC2485 Datasheet - Page 33

• Manufacturer Part Number: LTC2485
• Description: 24-Bit ?? ADC with Easy Drive Input Current Cancellation and I2C Interface
• Manufacturer: LINER [Linear Technology]

APPLICATIO S I FOR ATIO
Figure 40. Input Normal Mode Rejection 2x Speed Mode
Figure 42. Input Normal Mode Rejection vs Input
Frequency, 2x Speed Mode and 50Hz/60Hz Mode
–100
–120
–100
–120
–20
–40
–60
–80
–40
–60
–80
–20
0
0
0
0
NC1M4V0
25
f
U
N
INPUT SIGNAL FREQUENCY (f
G1
50
2f
MEASURED DATA
CALCULATED DATA
INPUT FREQUENCY (Hz)
+
N
75
U
3f
2
N
IN OUT
100 125
LT1236
GND
TRIM
4f
4
N
5f
6
5
N
150 175 200
W
V
V
V
V
T
6f
CC
REF
INCM
IN(P-P)
A
N
R7
8k
R8
1k
(OMEGA MPJ-K-F)
= 25°C
THERMOCOUPLE
= 5V
N
= 5V
)
7f
= 2.5V
= 5V
TYPE K
N
2485 F40
JACK
2485 F42
225
8f
Figure 44. Calibration Setup
N
U
ISOTHERMAL
R2
2k
26.3C
4
5
IN
IN
+
–
Figure 41. Input Normal Mode Rejection 2x Speed Mode
Figure 43. Input Normal Mode Rejection 2x Speed Mode
REF
REF
LTC2485
1
3
+
–
GND
–100
–120
V
–100
–110
–120
–130
–140
5V
–40
–60
–80
–20
CC
–80
–90
–70
2
8
CA0/F
0
248
48
SDA
SCL
CA1
DIFFERENTIAL INPUT SIGNAL FREQUENCY (Hz)
0
250
50
C8
1µF
6
7
9
10
INPUT SIGNAL FREQUENCY (f
2485 F44
252 254 256 258 260 262 264
52
1.7k
54
C7
0.1µF
NO AVERAGE
56
1.7k
58
RUNNING
AVERAGE
WITH
N
60
)
LTC2485
2485 F41
2485 F43
62
33
2485fa