Electronic Components Datasheet Search |
|
ICL3245ECBZ Datasheet(PDF) 11 Page - Intersil Corporation |
|
ICL3245ECBZ Datasheet(HTML) 11 Page - Intersil Corporation |
11 / 20 page 11 FN4900.9 February 27, 2006 (set), keeping the ICL32XXE powered down until FORCEON transitions high, or until a transition occurs on a receiver or transmitter input. The INVALID output signal switches low to indicate that invalid levels have persisted on all of the receiver inputs for more than 30 µs (see Figure 8), but this has no direct effect on the state of the ICL32XXE (see the next sections for methods of utilizing INVALID to power down the device). INVALID switches high 1 µs after detecting a valid RS-232 level on a receiver input. INVALID operates in all modes (forced or automatic powerdown, or forced on), so it is also useful for systems employing manual powerdown circuitry. The time to recover from automatic powerdown mode is typically 100 µs. Emulating Standard Automatic Powerdown If enhanced automatic powerdown isn’t desired, the user can implement the standard automatic powerdown feature (mimics the function on the ICL3221E/ICL3223E/ICL3243E) by connecting the INVALID output to the FORCEON and FORCEOFF inputs, as shown in Figure 9. After 30 µs of invalid receiver levels, INVALID switches low and drives the ICL32XXE into a forced powerdown condition. INVALID switches high as soon as a receiver input senses a valid RS- 232 level, forcing the ICL32XXE to power on. See the “INVALID DRIVING FORCEON AND FORCEOFF” section of Table 2 for an operational summary. This operational mode is perfect for handheld devices that communicate with another computer via a detachable cable. Detaching the cable allows the internal receiver pull-down resistors to pull the inputs to GND (an invalid RS-232 level), causing the 30 µs timer to time-out and drive the IC into powerdown. Reconnecting the cablerestores valid levels, causing the IC to power back up. Hybrid Automatic Powerdown Options For devices which communicate only through a detachable cable, connecting INVALID to FORCEOFF (with FORCEON = 0) may be a desirable configuration. While the cable is attached INVALID and FORCEOFF remain high, so the enhanced automatic powerdown logic powers down the RS- 232 device whenever there is 30 seconds of inactivity on the receiver and transmitter inputs. Detaching the cable allows the receiver inputs to drop to an invalid level (GND), so INVALID switches low and forces the RS-232 device to power down. The ICL32XXE remains powered down until the cable is reconnected (INVALID = FORCEOFF = 1) and a transition occurs on a receiver or transmitter input (see Figure 7). For immediate power up when the cable is reattached, connect FORCEON to FORCEOFF through a network similar to that shown in Figure 5. FIGURE 8. CONNECTIONS FOR AUTOMATIC POWERDOWN WHEN NO VALID RECEIVER SIGNALS ARE PRESENT FORCEOFF INVALID CPU I/O FORCEON ICL32XXE UART RECEIVER INPUTS TRANSMITTER OUTPUTS INVALID OUTPUT V+ VCC 0 V- tINVL tINVH FIGURE 9. ENHANCED AUTOMATIC POWERDOWN, INVALID AND READY TIMING DIAGRAMS READY OUTPUT TRANSMITTER INPUTS tWU tAUTOPWDN tAUTOPWDN tWU INVALID REGION } ICL3225E, ICL3227E, ICL3245E |
Similar Part No. - ICL3245ECBZ |
|
Similar Description - ICL3245ECBZ |
|
|
Link URL |
Privacy Policy |
ALLDATASHEET.NET |
Does ALLDATASHEET help your business so far? [ DONATE ] |
About Alldatasheet | Advertisement | 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 |