RS232 line driver wthout charge pumps?

[blapcb]

I use a MAX3232 for driving the RS232 line but it uses a charge pump that places a sawtooth wave on the power rail. Do all line drivers use charge pumps? Is there a better choice? (logic is 3.3v)

 

[sabeti_1990]

hi
can U use rs485 instate of 232 it's look like better in noise

 

[blapcb]

hi
can U use rs485 instate of 232 it's look like better in noise

No. Must be RS232.

 

[alexxx]

I use a MAX3232 for driving the RS232 line but it uses a charge pump that places a sawtooth wave on the power rail.

Can you post your schematic and measured waveforms? Are you using decoupling capacitors?

 

[poorchava]

and series inductior in power supply line?

 

[blapcb]

and series inductior in power supply line?

The schematic is just the text book schematic for this chip with all 0.1uF caps

No presently there is no inductor in series.