TX/RX/RS232 to 4bit

[ytem21]

Good day, anyone can give an idea about on how to convert Tx to bit. I want to convert my tx signals from pulser to CMOS gate so that I can drive the decade chips.



Thanks,
Daniel

 

[ADWSystems]

I'm not quite following your post. My first impression is that you you have a +/- 12V signal/pulse train that you want to connect to the clock input of a 5V CMOS chip (possibly a decade counter). In which I would recommend a MAX232 transceiver chip to do the logic level conversion. There are discrete component ways as well, but this solution is easiest to express in text.

Pieces that don't make sense based on your post include the fact that RS-232 is a serial data transmission protocol, so the incoming pulse train (should) contain actual information in which case you would need to convert the logic levels and then pass it through a serial-to-parallel converter chip to read the data one word at a time. Additionally, the Tx from one chip should be connnected to the Rx of the other and the Rx signal is the one to level shift from +/- 12V to +5V.

 

[ytem21]

Greatly thanks to your response ADWSystem, I have 5V signal/pulse that marked with Tx, This signal pulse i wanted to convert to +/-5V marked with S1 & S2 signals which is the requirements of the CPU.

It is possible that MAX232 can handle to convert this pulse from 5v Tx pulse to +/-5V pulse?


Very much Thanks,

Daniel

 

[ADWSystems]

Nope. For +/-5V you're on your own. +/-5V is not RS-232.

 

[ericgibbs]

Greatly thanks to your response ADWSystem, I have 5V signal/pulse that marked with Tx, This signal pulse i wanted to convert to +/-5V marked with S1 & S2 signals which is the requirements of the CPU.

It is possible that MAX232 can handle to convert this pulse from 5v Tx pulse to +/-5V pulse?


Very much Thanks,

Daniel

hi,
The MAX232 IC outputs signals of approx +/-9V, the +/-9V is produced by its internal switching circuits.

So it can accept a 5V TTL level input pulse on a TXI input pin and output +/-9V on the TXO pin.

 

[Blueteeth]

Theres nothing to say you can't clamp the output of a MAX232 (or equivilent) with zener diodes. The output current is limited anyway as it comes from an internal cap charge pump. Also, many MAX232-like-chips can work off 3.0-3.3V which would provide a +/-6V output, a simple load resistor to ground coudl drop that to +/-5V. I'm unsure exctly what it is you wish to do?

If you have a pulse train of RS232 levels, that you need to push into CMOS, then a simple transistor inverter would work nicely. An NPN, and two resistors is all you need. If you provided a rough diagram of the input signal, and what you want as an output I'm sure someone here could knock up a quick schem.