Electronic Components Datasheet Search
  English  ▼

Delete All
ON OFF
ALLDATASHEET.COM

X  

Preview PDF Download HTML

LTC1276 Datasheet(PDF) 21 Page - Linear Technology

Part No. LTC1276
Description  12-Bit, 300ksps Sampling A/D Converters with Reference
Download  24 Pages
Scroll/Zoom Zoom In 100% Zoom Out
Maker  LINER [Linear Technology]
Homepage  http://www.linear.com
Logo LINER - Linear Technology

LTC1276 Datasheet(HTML) 21 Page - Linear Technology

Back Button LTC1276_15 Datasheet HTML 16Page - Linear Technology LTC1276_15 Datasheet HTML 17Page - Linear Technology LTC1276_15 Datasheet HTML 18Page - Linear Technology LTC1276_15 Datasheet HTML 19Page - Linear Technology LTC1276_15 Datasheet HTML 20Page - Linear Technology LTC1276_15 Datasheet HTML 21Page - Linear Technology LTC1276_15 Datasheet HTML 22Page - Linear Technology LTC1276_15 Datasheet HTML 23Page - Linear Technology LTC1276_15 Datasheet HTML 24Page - Linear Technology  
Zoom Inzoom in Zoom Outzoom out
 21 / 24 page
background image
21
LTC1273
LTC1275/LTC1276
127356fa
S
APPLICATI
I FOR ATIO
Demodulating a Signal by Undersampling
with LTC1275
Figure 23 shows a 455kHz amplitude modulated input
undersampled by the LTC1275. With a 227.5kHz sample
rate, the converter provides a 100dB noise floor and 68dB
distortion when digitizing the 455kHz AM input.
Figure 24 shows an FFT of the AM signal digitized at
212.5kHz.
AIN
LTC1275
D11
D0
455kHz
AMPLITUDE
MODULATED
INPUT
RD
RD
–5V
227.5kHz
SAMPLE RATE
5V
LTC1273/75/76 • F23
DATA OUTPUT
Figure 23. A 455kHz Amplitude Modulated Input
Undersampled by the LTC1275
FREQUENCY (kHz)
0
–110
–90
–70
–50
–30
20
40
60
80
LTC1273/75/76 • F24
100
120
–10
–100
–80
–60
–40
–20
0
fSAMPLE = 212.5kHz
fIN = 454.8kHz
fMOD = 5.03kHz
Figure 24. 455kHz Input Voltage Modulated by a 5kHz Signal
A time domain view of the demodulation is shown in Figure
25. The top trace shows the 455kHz waveform modulated
by a – 6dB, 5kHz signal. The bottom trace shows the
demodulated signal produced by the LTC1275 recon-
structed through a 12-bit DAC. The resultant frequency is
5kHz with a sample rate of 227.5kHz. There are roughly 45
points per cycle.
Figure 25. 455kHz AM Signal Demodulated to 10.5 ENOBs
DEMODULATED
5kHz OUTPUT
455kHz
AM SIGNAL
50
µs/DIV
LTC1273/75/76 • F27
1V/DIV
1V/DIV
100ps Resolution
∆Time Measurement with LTC1273
Figure 26 shows a circuit that precisely measures the
difference in time between two events. It has a 400ns full
scale and 100ps resolution. The start signal releases the
ramp generator made up of the PNP current source and
the 250pF capacitor. The circuit ramps until the stop
signal shuts off the current source. The final value of the
ramp represents the time between the start and stop
events. The LTC1273 digitizes this final value and outputs
the digital data.


Html Pages

1  2  3  4  5  6  7  8  9  10  11  12  13  14  15  16  17  18  19  20  21  22  23  24 


Datasheet Download

Go To PDF Page


Link URL




Privacy Policy
ALLDATASHEET.COM
Does ALLDATASHEET help your business so far?  [ DONATE ]  

About Alldatasheet   |   Advertisement   |   Datasheet Upload   |   Contact us   |   Privacy Policy   |   Alldatasheet API   |   Link Exchange   |   Manufacturer List
All Rights Reserved© Alldatasheet.com


Mirror Sites
English : Alldatasheet.com  |   English : Alldatasheet.net  |   Chinese : Alldatasheetcn.com  |   German : Alldatasheetde.com  |   Japanese : Alldatasheet.jp
Russian : Alldatasheetru.com  |   Korean : Alldatasheet.co.kr  |   Spanish : Alldatasheet.es  |   French : Alldatasheet.fr  |   Italian : Alldatasheetit.com
Portuguese : Alldatasheetpt.com  |   Polish : Alldatasheet.pl  |   Vietnamese : Alldatasheet.vn