RS232 / TTL converter pin4

[Sarunas Nejus]

Hello guys,

I am looking for a RS232/TTL converter which works on 3.3V TTL logic levels/+-5V serial, and, most importantly, is able to power up pin 4 or pin 7 of RS232 side with 5V. All of the converters I found on the market only provide RXD(2), TXD(3) and GND(5) on RS232, such as here. Has anyone encountered this sort of a problem before?

Pin 4 or Pin 7 are required here to establish a successfull DCE-DCE communication, they act as a power supply for subsequent circuit.

Regards,
Sarunas

 

[Martaine2005]

Hi Sarunas,
I am not sure if you have seen these converters.
It does have pin 7 for power.
http://www.bb-elec.com/Products/Datasheets/232LPTTLxx-0712ds.pdf

Martin

 

[Sarunas Nejus]

Thanks for your response, Martin.

The converter looks not bad, unfortunately, it's powered from RS232 side and the problem is that my RS232 device does not hold any voltage on neither of its pins. It's waiting for a request from the controller (TTL).

 

[AnalogKid]

Are you looking for a complete product, or a chip?

ak

 

[Sarunas Nejus]

Complete product.

Despite that, I know that the most popular chip for this sort of conversion is MAX(3)232, however, none of the designs I've checked actually provide anything for Pin4 or 7.

 

[AnalogKid]

Maxim, LTC, and TI have huge numbers of other parts, single chips with enough circuits in them for a full RS-232 interface.

ak