 |
Electronic Components Datasheet Search |
|
|
Electronic Components Datasheet Search |
|
LTC4307IMS8 Datasheet(PDF) 9 Page - Linear Technology |
|
||||||||||||||||||||||||||||||
LTC4307IMS8 Datasheet(HTML) 9 Page - Linear Technology |
|
|
9 / 16 page  LTC4307 9 4307f OPERATION Bus Stuck Low Timeout When SDAOUT or SCLOUT is low, an internal timer is started. The timer is only reset by that respective input going high. If it does not go high within 30ms (typical) the connection between SDAIN and SDAOUT, and between SCLIN and SCLOUT is broken. After at least 40μs, the LTC4307 automatically generates up to 16 clock pulses at 8.5kHz (typical) on SCLOUT in an attempt to unstick the bus. When the clock pulses are completed, a stop bit will be generated on SCLOUT and SDAOUT to reset any circuity on that bus. When the low SDAOUT or SCLOUT pin goes high, a connection is enabled waiting for a stop bit or a bus idle to make a connection. When powering up into a bus stuck low condition, the connection circuitry joining the SDA and SCL busses on the I/O card with those on the backplane is not activated and is only reset when SDAOUT and SCLOUT are high. 30ms after UVLO, automatic clocking takes place as described above. READY Digital Output This pin provides a digital flag which is low when either ENABLE is low, the start-up sequence described earlier in this section has not been completed, or the LTC4307 has disconnected due to a stuck bus condition. READY goes high when ENABLE is high and the backplane and card sides are connected. The pin is driven by an open-drain pull-down capable of sinking 3mA while holding 0.4V on the pin. Connect a resistor to VCC to provide the pull-up. ENABLE When the ENABLE pin is driven below 0.8V with respect to the LTC4307’s ground, the backplane side is disconnected from the card side and the READY pin is internally pulled low. When the pin is driven above 2V, the part waits for data transactions on both the backplane and card sides to be complete (as described in the Start-Up section) before connecting the two sides. At this time the internal pull- down on READY releases. When ENABLE is low, automatic clocking is disabled. A rising edge on ENABLE after a bus stuck low condition has occurred forces a connection between SDAIN, SDAOUT, and SCLIN, SCLOUT even if the bus stuck low condition has not been cleared. At this time the 30ms timer is reset but not disabled. Rise Time Accelerators Once connection has been established, rise time accelerator circuits on all four SDA and SCL pins are enabled. During positive bus transitions, the rise time accelerators provide strong, slew-limited pull-up currents that make the bus voltage rise at a rate of 100V/μs. The rise time accelerators significantly improve system reliability in two ways. First, they provide smooth, controlled transitions during rising edges for both small and large systems. Because the ac- celerator pull-up impedance is significantly lower than the bus pull-up resistance, the system is much less susceptible to noise on rising edges. Second, the accelerators allow users to choose large bus pull-up resistors, reducing power consumption and improving logic low noise margin. For these reasons, it is strongly recommended that users choose bus pull-up resistors so that the bus will rise on its own at a rate of at least 0.8V/μs to guarantee activation of the accelerators. The rise time accelerators are disabled until the sequence of events described in the start-up sec- tion has been completed. They are also disabled during automatic clocking. Figure 2. Input-Output Rising Edge Waveforms Figure 3. Input-Output Falling Edge Waveforms OUTPUT SIDE 50pF 1V/DIV INPUT SIDE 150pF 1V/DIV 200ns/DIV 4307 F02 INPUT SIDE 150pF 1V/DIV OUTPUT SIDE 50pF 1V/DIV 200ns/DIV 4307 F03 |
Similar Part No. - LTC4307IMS8 |
|
Similar Description - LTC4307IMS8 |
|
|
|
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
