 |
Electronic Components Datasheet Search |
|
|
Electronic Components Datasheet Search |
|
LTC4311CSC6-TRMPBF Datasheet(PDF) 9 Page - Linear Technology |
|
||||||||||||||||||||||||||||||
LTC4311CSC6-TRMPBF Datasheet(HTML) 9 Page - Linear Technology |
|
|
9 / 12 page  LTC4311 9 4311fa APPLICATIONS INFORMATION This is the lowest resistor value that may be chosen and still meet VOL. Next calculate the largest value of RP that will satisfy SR, the minimum slew rate requirement. Us- ing VOL = 0.4V and SR = 0.5V/μs calculate the value of RP with equation 2. R P = 3.3V −0.4V 600pF •0.5V / µs R P = 9.667k (11) This is approximately the largest value of RP that will satisfy the minimum slew rate requirement. Since RP is larger than 2.175k the VOL will be below 0.4V, and the slew rate will actually be faster than calculated. Choosing RP = 10k , VOL and SR are recalculated. V OL = 300 Ω•3.3V 300 Ω+10kΩ =96mV SR = 3.3V – 96mV 10k Ω•600pF =0.534V / µs (12) The rise and fall times need to be verified using equations 3 and 4. t r = –10kΩ• 600pF • In 2.31V – 3.3V – 10k Ω • 2.5mA 0.99V – 3.3V – 10k Ω • 2.5mA ⎧ ⎨ ⎩ ⎫ ⎬ ⎭ = 0.297µs (13) t f = 291Ω• 600pF • In 2.31 3.3V •(10kΩ+ 300Ω)– 300Ω 0.99V 3.3V •(10kΩ+ 300Ω)– 300Ω ⎧ ⎨ ⎪ ⎩ ⎪ ⎫ ⎬ ⎪ ⎭ ⎪ = 0.158µs (14) Both the rise and fall times meet the 0.3μs I2C requirement and the VOL is satisfied, while meeting the minimum slew rate requirement, so RP is chosen to be 10k. If tr is not met, RP should be decreased and if tf is not met then RP should be increased. SMBus Design Example Given the following conditions and requirements for a low power SMBus system: V CC = 3.3V NOMINAL V OL = 0.4V MAXIMUM C BUS = 400pF V ILMAX = 0.8V, VIHMIN = 2.1V t r = 1µs MAXIMUM, t f = 0.3µs MAXIMUM (15) If an RS of 100Ω is used and the max RON of the driver is 200Ω, then RL = 200Ω + 100Ω = 300Ω. Use equation 1 to find the required RP to meet VOL. R P = 300 Ω•(3.3V –0.4V) 0.4V R P = 2.175k (16) Calculate Maximum RP from equation 2. R P = 3.3V – 0.4V 400pF •0.5V / µs R P = 14.5k (17) Choose RP = 13k and recalculate VOL and SR. V OL = 300 Ω•3.3V 300 Ω+ 13kΩ = 74mV SR = 3.3V – 74mV 13k Ω• 400pF = 0.62V / µs (18) The rise and fall times need to be verified using equations 5 to 8. t 1 = –13kΩ• 400pF • ln 0.9V–3.3V 0.8V–0.15V–3.3V ⎧ ⎨ ⎩ ⎫ ⎬ ⎭ = 0.515µs (19) |
Similar Part No. - LTC4311CSC6-TRMPBF |
|
Similar Description - LTC4311CSC6-TRMPBF |
|
|
|
Link URL |
| Privacy Policy |
| ALLDATASHEET.COM |
| Does ALLDATASHEET help your business so far? [ DONATE ] |
About Alldatasheet | Advertisement | Datasheet Upload | Contact us | Privacy Policy | Link Exchange | Manufacturer List 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 |
English ▼
English
Chinese
German
Japanese
Russian
Korean
Spanish
French
Italian
Portuguese
Polish
Vietnamese
Indian
Mexican
British
New Zealand
