| ??? 02/02/05 04:57 Read: times Msg Score: 0 -1 Off-Topic +1 Underrated |
#86344 - /CE propagaion delay in MAX691 |
Hi,
Consider a MAX691 used both as battery back up controller of an SRAM and as an RC reset circuit replacement in a 89C51 system. 
MAX691 datasheet page 3 (Electrical Characteristics) says: /CE propagation delay typical time is 50ns. Now, 1) How can we detrmine whether or not this 50ns (max. 200ns) propagation delay between /CEin and /CEout of MAX691 is not too slow to be fed to /CS of SRAM? 2) Is it not better not to use this feature? i.e. no-connect the /CEin and /CEout of MAX691 and simply pull-up the /CS of SRAM with 10K resistor to Vout of MAX691 so that whenever the system is turned off and the battery is in use and the original /CS signal comming from some address decoder does not have a valid value, this 10K resistor will automatically deselect the SRAM? 3) How long does a typical 3v lithium battery live in a system using MAX691+SRAM+Battery? Best. |
| Topic | Author | Date |
| /CE propagaion delay in MAX691 | 01/01/70 00:00 | |
| Prop delay in max691 | 01/01/70 00:00 | |
| Batteries | 01/01/70 00:00 | |
| or check out the FLASH+RAM combination | 01/01/70 00:00 | |
| FRAM | 01/01/70 00:00 | |
| another option | 01/01/70 00:00 | |
| ZMD | 01/01/70 00:00 | |
| that's the one | 01/01/70 00:00 | |
| MAX691+battery | 01/01/70 00:00 | |
| what is the problem | 01/01/70 00:00 | |
| How can that be off topic | 01/01/70 00:00 | |
| the matter | 01/01/70 00:00 | |
| It's definitely on-topic! | 01/01/70 00:00 | |
| NEVER design with typicals | 01/01/70 00:00 | |
| MAX691 versus MAX691A, leakage currents | 01/01/70 00:00 | |
| take note, Kai is using the right value | 01/01/70 00:00 | |
| MAX691A | 01/01/70 00:00 | |
| EEPROM | 01/01/70 00:00 | |
| EEprom | 01/01/70 00:00 | |
| And..... | 01/01/70 00:00 | |
| more Qs on /CE | 01/01/70 00:00 | |
| This is more like a valid question | 01/01/70 00:00 | |
timing diagrams | 01/01/70 00:00 |