| 전자부품 데이터시트 검색엔진 |
|
AN3137 데이터시트(PDF) 31 Page - STMicroelectronics |
|
|
|||||||||||||||||||||||||||||
AN3137 데이터시트(HTML) 31 Page - STMicroelectronics |
|
31 / 42 page ![]() AN3137 Methods for precision improvement Doc ID 16983 Rev 3 31/42 where Ulsb ..... 0.5 lsb voltage level Qcharging = Qdischarging After simplification, we obtain the final formula for the required waiting time between conversions: This final formula links the external capacitor Cext and the required waiting time between two conversions if the precision Ulsb is needed. From the same formula you can see that the argument in logarithm must be positive and therefore there is a condition for the minimal value of Cext: Choosing a larger Cext decreases more the time between conversions (tC). An extra large Cext (Cext>>Csh U max U lsb -------------- ⋅ ) enables sampling more often. However, increasing Cext limits the frequency bandwidth of measurement signal (increasing the “external” timing constant Rin . Cext). The formulas below show how to choose the optimal Cext value: signal bandwidth in correlation with sample time. Signal bandwidth is characterized by an “external” timing constant, so: C sh U max ⋅ U lsb R in ----------- e t R in Cext ------------------- t d 0 t C ∫ ⋅ = t C R in C ext ⋅ () – In 1 C sh C ext ----------- U max U lsb -------------- – ⋅ = 1 C sh C ext ----------- U max U lsb -------------- – 0 > 1 C sh C ext ----------- U max U lsb -------------- > C ext C sh U max U lsb -------------- ⋅ > R in C ext ⋅ () t C = R in C ext ⋅ () R in C ext ⋅ () – In 1 C sh C ext ----------- U max U lsb -------------- – ⋅ = |
|
링크 URL |
| ALLDATASHEET 가 귀하에 도움이 되셨나요? [ DONATE ] |
Alldatasheet는? | 광고문의 | 운영자에게 연락하기 | 개인정보취급방침 | 링크 투 데이터시트 | 링크교환 | 제조사별 검색 All Rights Reserved©Alldatasheet.com |
| 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 |