Hi everyone,
I need to work on an analog switch which will switch the RS232 (+/- 10VDC) signal from different RS232 serial communication.
I tried ADG333 with MAX232IDR, but it will draw too much current when RS232 is in Mark (-8.9VDC), then it will pull it to -0.89VDC.
Does everyone how to make analog switch for RS232 signals?
Thanks for help.
Hi KRZ,
Since I use a single power supply of +5VDC to MAX232, and +12VDC for ADG333(it was +5VDC incorrect on the schematics.
when TTL is 0 (0VDC-Ground), RS232 Level is +8.57VDC, the ADG on COM is +8.57VDC, then NC/NO works as expected,
However When TTL is 1 (+5VDC), if no connected to ADG333 on COM, RS232 Level will be -8.57VDC(negative). but once I connect it to ADG333 on COM, it drops to -0.67V, it did not stay -8.57VDC, and draw 0.02mA. What went wrong with TTL Logic Truth (1)?
Please review this part of schematics. Thanks
Hi KRZ,
Since I use a single power supply of +5VDC to MAX232, and +12VDC for ADG333(it was +5VDC incorrect on the schematics.
when TTL is 0 (0VDC-Ground), RS232 Level is +8.57VDC, the ADG on COM is +8.57VDC, then NC/NO works as expected,
However When TTL is 1 (+5VDC), if no connected to ADG333 on COM, RS232 Level will be -8.57VDC(negative). but once I connect it to ADG333 on COM, it drops to -0.67V, it did not stay -8.57VDC, and draw 0.02mA. What went wrong with TTL Logic Truth (1)?
Please review this part of schematics. Thanks
