Electronic Components Datasheet Search |
|
MAX6372KA-T Datasheet(PDF) 8 Page - Maxim Integrated Products |
|
MAX6372KA-T Datasheet(HTML) 8 Page - Maxim Integrated Products |
8 / 8 page Pin-Selectable Watchdog Timers Selecting 011 (SET2 = 0, SET1 = 1, SET0 = 1) disables the watchdog timer function on all devices in the family. Operation can be reenabled without powering down by changing the set inputs to the new desired setting. The device assumes the new selected timing characteris- tics and enter the startup phase after the 300µs setup time elapses (Figure 3). The MAX6373/MAX6374 offer a first-edge feature. In first-edge mode (settings 101 or 110, Table 1), the internal timer does not control the startup delay period. Instead, startup terminates when WDI sees a transition. If changing to first-edge mode while the device is oper- ating, disable mode must be entered first. It is then safe to select first-edge mode. Entering disable mode first ensures the output is unasserted when selecting first- edge mode and removes the danger of WDI being masked out. Output The MAX6369/MAX6371/MAX6373 have an active-low, open-drain output that provides a watchdog output pulse of 100ms. This output structure sinks current when WDO is asserted. Connect a pullup resistor from WDO to any supply voltage up to +5.5V. Select a resistor value large enough to register a logic low (see Electrical Characteristics), and small enough to register a logic high while supplying all input current and leakage paths connected to the WDO line. A 10k Ω pullup is sufficient in most applications. The MAX6370/ MAX6372/MAX6374 have push-pull outputs that pro- vide an active-low watchdog output pulse of 1ms. When WDO deasserts, timing begins again at the beginning of the watchdog timeout period (Figure 2). Usage in Noisy Environments If using the watchdog timer in an electrically noisy envi- ronment, a bypass capacitor of 0.1µF should be con- nected between VCC and GND as close to the device as possible, and no further away than 0.2 inches. ________________Watchdog Software Considerations To help the watchdog timer monitor software execution more closely, set and reset the watchdog input at differ- ent points in the program, rather than pulsing the watch- dog input high-low-high or low-high-low. This technique avoids a stuck loop, in which the watchdog timer would continue to be reset inside the loop, keeping the watch- dog from timing out. Figure 4 shows an example of a flow diagram where the I/O driving the watchdog input is set high at the beginning of the program, set low at the end of every subroutine or loop, then set high again when the program returns to the beginning. If the pro- gram should hang in any subroutine, the problem would be quickly corrected, since the I/O is continually set low and the watchdog timer is allowed to time out, causing WDO to pulse. START SET WDI HIGH PROGRAM CODE SUBROUTINE OR PROGRAM LOOP SET WDI LOW RETURN POSSIBLE INFINITE LOOP PATH Figure 4. Watchdog Flow Diagram Chip Information TRANSISTOR COUNT: 1500 PROCESS: BiCMOS SET2 SET1 SET0 1 2 8 7 VCC WDO GND N.C. WDI SOT23-8 TOP VIEW 3 4 6 5 MAX6369 MAX6370 MAX6371 MAX6372 MAX6373 MAX6374 Pin Configuration Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied. Maxim reserves the right to change the circuitry and specifications without notice at any time. 8 _____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 © 2003 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products. |
Similar Part No. - MAX6372KA-T |
|
Similar Description - MAX6372KA-T |
|
|
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 |