Here is the situation I've run into. I have a device that had a voltage regulator that didnt work to well. There for I switched to a diffrent regulator, and it seems to work really well. But when I built the prototype power supply, I ran into a little issue.
The insturment uses a single button on/off. This was done using a MAX1672 that uses ONA and ONB. This IC would turn on when (ONB not) went low, and as soon as the microcontroller got power, it took over and put ONA high, which keep the powersupply on. When shutting off, the microcontroller detected (ONB not) going low and would start a shutdown sequence, and the microcontroller would then put ONA low shutting down the supply. If this sound confusing here is a truth table.
ONA---(ONB NOT)---MAX1672
0-----------0----------On
0-----------1----------Off
1-----------0----------On
1-----------1----------On
Now what I am using is a MAX887, which uses (SHDN Not). So when (SHDN Not) was high, the regulator was running. When (SHDN Not) went low the regulator was off.
So basicly I'm asking how I could get the MAX887 SHDN to work with something that was made for ONA and (SHDN Not)? Could I use some sort of flip flop or something? I'm very confused on what to do........
The insturment uses a single button on/off. This was done using a MAX1672 that uses ONA and ONB. This IC would turn on when (ONB not) went low, and as soon as the microcontroller got power, it took over and put ONA high, which keep the powersupply on. When shutting off, the microcontroller detected (ONB not) going low and would start a shutdown sequence, and the microcontroller would then put ONA low shutting down the supply. If this sound confusing here is a truth table.
ONA---(ONB NOT)---MAX1672
0-----------0----------On
0-----------1----------Off
1-----------0----------On
1-----------1----------On
Now what I am using is a MAX887, which uses (SHDN Not). So when (SHDN Not) was high, the regulator was running. When (SHDN Not) went low the regulator was off.
So basicly I'm asking how I could get the MAX887 SHDN to work with something that was made for ONA and (SHDN Not)? Could I use some sort of flip flop or something? I'm very confused on what to do........