 |
Zakładka z wyszukiwarką danych komponentów |
|
|
Zakładka z wyszukiwarką danych komponentów |
|
HCPL-M611 Arkusz danych(PDF) 8 Page - Agilent(Hewlett-Packard) |
|
||||||||||||||||||||||||||||||
HCPL-M611 Arkusz danych(HTML) 8 Page - Agilent(Hewlett-Packard) |
|
|
8 / 10 page  8 PropagationDelay,Pulse- Width Distortion and PropagationDelaySkew Propagation delay is a figure of merit which describes how quickly a logic signal propagates through a system. The propaga- tion delay from low to high (tPLH) is the amount of time required for an input signal to propagate to the output, causing the output to change from low to high. Similarly, the propagation delay from high to low (tPHL) is the amount of time required for the input signal to propagate to the output, causing the output to change from high to low (see Figure 7). Pulse-width distortion (PWD) resultswhen tPLHand tPHLdiffer in value. PWD is defined as the difference between tPLH and tPHL and often determines the maxi- mum data rate capability of a transmission system. PWD can be expressed in percent by dividing the PWD (in ns) by the minimum pulse width (in ns) being transmitted. Typically, PWD on the order of 20-30% of the minimum pulse width is tolerable; the exact figure depends on the particular application (RS232, RS422, T-1, etc.). Propagation delay skew, tPSK, is an important parameter to consider in parallel data appli- cations where synchronization of signals on parallel data lines is a concern. If the parallel data is being sent through a group of optocouplers, differences in propagation delays will cause the data to arrive at the outputs of the optocouplers at different times. If this difference in propagation delays is large enough, it will determine the maximum rate at which parallel data can be sent through the optocouplers. Propagation delay skew is defined as the difference between the minimumandmaximum propagation delays, either tPLH or tPHL, for any given group of optocouplers which are operating under the same conditions (i.e., the same drive current, supply voltage, output load, and operating temperature). As illustrated in Figure 15, if the inputs of a group of optocouplers are switched either ON or OFF at the same time, tPSK is the difference between the shortest propagation delay, either tPLHor tPHL, and the longest propagation delay, either tPLH or tPHL. As mentioned earlier, tPSK can determinethemaximumparallel data transmission rate. Figure 11 is the timing diagram of a typical parallel data application with both the clock and the data lines being sent through optocouplers. The figure shows data and clock signals at the inputs and outputs of the optocouplers. To obtain the maximumdatatransmissionrate, both edges of the clock signal are being used to clock the data; if only one edge were used, the clock signal would need to be twice as fast. Propagation delay skew represents the uncertainty of where an edge might be after being sent through an optocoupler. Figure 16 shows that there will be uncertainty in both the data and the clock lines. It is important that these two areas of uncertainty not overlap, otherwise the clock signal might arrive before all of the data outputs have settled, or some of the data outputs may start to change before the clock signal has arrived. From these considerations, the absolute minimum pulse width that can be sent through optocouplers in a parallel application is twice tPSK. A cautious design should use a slightly longer pulse width to ensure that any additional uncertainty in the rest of the circuit does not cause a problem. The tPSK specified optocouplers offer the advantages of guaranteed specifications for propagation delays, pulse-width distortion and propagation delay skew over the recommended temperature, and input current, and power supply ranges. |
Podobny numer części - HCPL-M611 |
|
Podobny opis - HCPL-M611 |
|
|
|
Link URL |
| Polityka prywatności |
| ALLDATASHEET.PL |
| Czy Alldatasheet okazała się pomocna? [ DONATE ] |
O Alldatasheet | Reklama | Kontakt | Polityka prywatności | Linki | Lista producentów 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 |
Polish ▼
English
Chinese
German
Japanese
Russian
Korean
Spanish
French
Italian
Portuguese
Polish
Vietnamese
Indian
Mexican
British
New Zealand
