LTC2448 LINER [Linear Technology], LTC2448 Datasheet - Page 22
![no-image](/images/no-image-200.jpg)
LTC2448
Manufacturer Part Number
LTC2448
Description
24-Bit High Speed 8-/16-Channel ADCs with Selectable Speed/Resolution
Manufacturer
LINER [Linear Technology]
Datasheet
1.LTC2448.pdf
(28 pages)
Available stocks
Company
Part Number
Manufacturer
Quantity
Price
Company:
Part Number:
LTC2448CUHF
Manufacturer:
LT
Quantity:
10 000
Part Number:
LTC2448CUHF#PBF
Manufacturer:
LINEAR/凌特
Quantity:
20 000
Company:
Part Number:
LTC2448CUHF#PBF/IU
Manufacturer:
LT
Quantity:
6
Part Number:
LTC2448CUHF#TRPBF
Manufacturer:
LINEAR/凌特
Quantity:
20 000
Company:
Part Number:
LTC2448IUHF
Manufacturer:
LT
Quantity:
10 000
Part Number:
LTC2448IUHF#PBF
Manufacturer:
LT/凌特
Quantity:
20 000
APPLICATIO S I FOR ATIO
LTC2444/LTC2445/
LTC2448/LTC2449
Normal Mode Rejection and Antialiasing
One of the advantages delta-sigma ADCs offer over con-
ventional ADCs is on-chip digital filtering. Combined with
a large oversampling ratio, the LTC2444/LTC2445/
LTC2448/LTC2449 significantly simplify antialiasing filter
requirements.
The LTC2444/LTC2445/LTC2448/LTC2449’s speed/reso-
lution is determined by the over sample ratio (OSR) of the
on-chip digital filter. The OSR ranges from 64 for 3.5kHz
output rate to 32,768 for 6.9Hz (in No Latency mode)
output rate. The value of OSR and the sample rate f
determine the filter characteristics of the device. The first
NULL of the digital filter is at f
f
frequency f
22
N
= f
S
/OSR, see Figure 10 and Table 7. The rejection at the
Figure 10. LTC2444/LTC2445/LTC2448/LTC2449
Normal Mode Rejection (Internal Oscillator)
–100
–120
–140
–20
–60
–40
–80
N
0
±14% is better than 80dB, see Figure 11.
0
DIFFERENTIAL INPUT SIGNAL FREQUENCY (Hz)
SINC
U
60
4
ENVELOPE
U
120
N
and multiples of f
180
W
2440 F11
240
U
N
where
S
Table 7. OSR vs Notch Frequency (f
Running at 9MHz)
*Simultaneous 50/60Hz rejection
Figure 11. LTC2444/LTC2445/LTC2448/LTC2449
Normal Mode Rejection (Internal Oscillator)
–100
–110
–130
–140
–120
32768*
–80
–90
16384
1024
2048
4096
8192
OSR
128
256
512
64
47
DIFFERENTIAL INPUT SIGNAL FREQUENCY (Hz)
49
51
53
55
N
57
) (with Internal Oscillator
59
NOTCH (f
28.16kHz
14.08kHz
7.04kHz
3.52kHz
1.76kHz
880Hz
440Hz
220Hz
110Hz
61
55Hz
2440 F12
sn2444589 2444589fs
63
N
)