ABOUT IR communication - some help needed

[shanren]

ABOUT IR communication

hi,i have a prolem.now i am design a IR transceiver,but i know nothing about it.can anybody give me some info?
i need a near distance,about 57.6kbps data rate.my problem is:
which photodiode is better?i did one,but data rate only 9.6kbps and sometimes 19.2kbps,but can not work at higher rate.
thanks for any info.

 

[arturt134]

I have used TSHF5400 IR LED (Sharp, I think so) and SFH314 fototransistor (Siemens). Distance was about 1 meter, and data rate 115200 bit/s.
Regards

 

[flatulent]

Many years ago I build such a system and used Siemen parts. I used an EXAR vco and an audio range PLL tone decoder. The "Light" was pulsed on and off at a rate about 5 times the bit rate. One of the keys to the system was a lense on the receiver. Edmund Scientific was the source for that. Another key to the circuit was using a current to voltage converter op amp circuit from the book Photodiode Amplifiers by Jerald Graeme. The transmitter used several LED sources in series to increase the optical power output .

 

[coppervaporlaser]

I would check the capacitive load of the receive path. Also try minimizing the feedback resistance of the input opamp (if there is any).
Why not using modulated laser diode ?

 

[coppervaporlaser]

I would check the capacitive load of the receive path. Also try minimizing the feedback resistance of the input opamp (if there is any).
Why not using modulated laser diode ?

 

[shanren]

thanks all!
i will try the parts.but maybe laser diode are expensive,and sometimes the ir emmiter can not just face the photodiode,and they are placed very closed,so maybe the laser diode can not work.
in fact,what trouble me is it can commulate sometimes,but can not sometimes.