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lvds receiver power consumption

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Hello
I have 4 devices sending RS232 data continuosly. Those streams are converted to LVDS and transmitted over 4 couples of wires. On the other side, there is a SN65LVDT33D converting to TTL and a PIC micro with 4 UARTS. All is working fine, but the problem is that SN65LVDT33D draws 16mA when idle, which is too much for this app.
I had a look, it seems that all LVDS receivers have more or less this power consumption. Anyone can explain why? Is there any way to overcome this?
Thank you
 

LVDS receivers have an analog comparator type front end (for
common mode rejection and gain) which will burn some power.
Power is needed for speed. You might look for some older and
lower speed versions if you're only running RS-232 baud rates.

Seems like the intermediate RS-232 to LVDS layer is a waste
of material and power, when you could just use an RS-232
receiver at the destination end.

You could consider trying an ultra low power CMOS comparator
instead of an LVDS receiver, especially if you are not too
concerned about things like input failsafe modes.
 

dick_freebird said:
LVDS receivers have an analog comparator type front end (for
common mode rejection and gain) which will burn some power.
Power is needed for speed. You might look for some older and
lower speed versions if you're only running RS-232 baud rates.
Click to expand...
First of all, thank you for replying.
You are right. I forgot to mention that baud rate is very low (4800 or 9600).
However I could not find any "old" device. If you can suggest one, you are welcome.
Seems like the intermediate RS-232 to LVDS layer is a waste
of material and power, when you could just use an RS-232
receiver at the destination end.
Click to expand...
Double conversion looks like a waste, but unfortunately is a requirement for this application to avoid cross talk (transmission line is deployed inside a very sensitive data acquisition environment).
You could consider trying an ultra low power CMOS comparator
instead of an LVDS receiver, especially if you are not too
concerned about things like input failsafe modes.
Click to expand...
This is a good idea. The only problem is space limitation: the board has to be very small and the LVDS converter was small enough. Using a comparator implies adding many resistors.
If you are aware of anything else that could come useful, please tell me. Otherwise I have to use comparators and enlarge the board.
 

A CMOS rail-rail-input comparator that just looks at the two
differential signals, ought to need no resistors. So long as the
electrical environment is benign (no gross ground offset,
etc.).

You might try and set up a test case in LTCSpice using one
of theirs, and see how it goes.
 

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