Electronic Components Datasheet Search |
|
P82B715 Datasheet(PDF) 9 Page - NXP Semiconductors |
|
P82B715 Datasheet(HTML) 9 Page - NXP Semiconductors |
9 / 23 page P82B715_8 © NXP B.V. 2009. All rights reserved. Product data sheet Rev. 08 — 9 November 2009 9 of 23 NXP Semiconductors P82B715 I2C-bus extender Figure 8 shows P82B715 in an analog radial IPMB shelf application. In this example the total system capacitance is 2800 pF, but it is distributed over 18 different bus sections and no section has a capacitance greater than 200 pF. If every individual bus section is designed to rise at least as fast as the IPMB requirement, then when any driver releases the bus, all bus sections will rise together and no amplifiers in the P82B715s will be activated or, if one is activated, it can only slow the system bus rise to its own rate and that has been designed to meet the requirement. It is then only necessary to calculate the equivalent static bus pull-up loading and to ensure that it exceeds the specification requirement. The calculated loadings meet the requirements. Note that in this example only one of the four IPMB lines is shown and the usual switching arrangements for isolating or cross-connecting bus lines are not shown. The typical offset (increase in the bus LOW level) measured between any two Sx points in this system is below 100 mV. Calculation of static loading at ShMM buffer and each FRU: Loading on ShMM buffer = R1 || {10 (R2 || R3/16)} = 3.5 kΩ Loading on each FRU = R3 || {10 (R1 || R2 || R3/15)} = 3.76 kΩ Fig 8. Typical arrangement and calculations for an IPMB analog radial shelf 002aad708 Lx Sx R1 3.3 V effective capacitance at ShMM buffer ShMM buffer pull-up ShMM buffer strays P82B715 total capacitance C1 10 pF 20 pF 10 pF 40 pF R1 = = 25 k Ω 1 µs 40 pF effective capacitance at common Lx node Lx common pull-up 17 × P82B715 trace capacitance total capacitance C2 170 pF 30 pF 200 pF R2 = = 5 k Ω 1 µs 200 pF effective capacitance at average radial trace radial trace pull-up 1 × FRU radial trace/connector P82B715 total capacitance C3 25 pF 125 pF 10 pF 160 pF R3 = = 6.2 k Ω 1 µs 160 pF Calculations to ensure rise time is met on each bus section: BUFFER ShMM C1 R2 C2 Lx Sx 1 R3 C3 Lx Sx 2 R3 C3 radial traces Lx Sx 16 R3 C3 BUFFER µC FRU 1 BUFFER µC FRU 2 BUFFER µC FRU 16 common Lx node |
Similar Part No. - P82B715 |
|
Similar Description - P82B715 |
|
|
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 |