Motore di ricerca datesheet componenti elettronici
  Italian  ▼
ALLDATASHEETIT.COM

X  

Preview PDF HTML

AN2846 Scheda tecnica(PDF) 10 Page - STMicroelectronics

Il numero della parte AN2846
Spiegazioni elettronici  The serial current limited termination device
PDF  35 Pages
Scroll/Zoom Zoom In 100%  Zoom Out
Produttore elettronici  STMICROELECTRONICS [STMicroelectronics]
Homepage  http://www.st.com
Logo STMICROELECTRONICS - STMicroelectronics

AN2846 Scheda tecnica(HTML) 10 Page - STMicroelectronics

Back Button AN2846 Datasheet HTML 6Page - STMicroelectronics AN2846 Datasheet HTML 7Page - STMicroelectronics AN2846 Datasheet HTML 8Page - STMicroelectronics AN2846 Datasheet HTML 9Page - STMicroelectronics AN2846 Datasheet HTML 10Page - STMicroelectronics AN2846 Datasheet HTML 11Page - STMicroelectronics AN2846 Datasheet HTML 12Page - STMicroelectronics AN2846 Datasheet HTML 13Page - STMicroelectronics AN2846 Datasheet HTML 14Page - STMicroelectronics Next Button
Zoom Inzoom in Zoom Outzoom out
 10 / 35 page
background image
Application guidelines
AN2846
10/35
Doc ID 15130 Rev 1
1.2.4
Input signal frequency limitation
The maximum frequency transmitted trough the current limited inputs is limited by 3 factors:
1.
The input digital filter, which cuts undesirable frequencies. ROSC set to 51 kΩ and
DVR connected to GND ensures that the input signal has to be at a stable level for
more than 20 µs to be taken into account. This allows a maximum input frequency of
25 kHz. It can be reduced to 130 Hz using the combination of ROSC = 1.5 MΩ and DVR
connected to VDD.
2.
The input capacitors CIN are used to increase the EMI immunity filter of the input
signal. RIN = 2.2 kΩ and CIN = 22 nF ensures a 3.2 kHz low pass filter.
3.
The SPI sampling effect - the input states are taken into account at each /CS fall (see
Section 1.4.4). This achieves a sampling of inputs at the /CS frequency, as shown in
Figure 11. The input states will be correctly transmitted if the sampling mode meets the
Shannon equation:
Figure 11.
Sampling effect
As the /CS period is dependant on the frame length, Table 2 below gives some useful
combinations of SCK frequency signal, frame length and current limited input frequency.
frequency
input
max
F
with
period
signal
/CS
the
t
with
:
t
1
F
with
F
2
F
Input
/CS
/CS
/CS
Input
CS
/
=
=
•
=
tINPUT
/CS
Current limited Input signal
Low level capture
missed
High level capture
missed
t
/CS
Table 2.
Input frequency versus SCK and length frame
FSCK
0.1
1.0
2.0
MHz
Frame length
8
16
32
64
8
16
32
64
8
16
32
64
bits
t/CS
80
160
320
640
8
16
32
64
4
8
16
32
µs
Fcurrent limited input
6.25
3.125
1.56
0.78
62.5
31.25
15.6
7.8
125
62.5
31.25
15.6
kHz



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 25 26 27 28 29 30 31 32 33 34 35


Scheda tecnica Scarica

Go To PDF Page


Link URL



Lei ha avuto il aiuto da alldatasheet?  [ DONATE ] 

Di alldatasheet   |   Richest di pubblicita   |   contatti   |   Privacy Policy   |   Collegamento alla scheda tecnica    |   scambio Link   |   Ricerca produttore
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
Indian : Alldatasheet.in  |   Mexican : Alldatasheet.com.mx  |   British : Alldatasheet.co.uk  |   New Zealand : Alldatasheet.co.nz
Family Site : ic2ic.com  |   icmetro.com