LT1328CMS8 View Datasheet(PDF) - Linear Technology
Part Name
Description
MFG CO.
'LT1328CMS8' PDF : 12 Pages View PDF
LT1328
APPLICATIONS INFORMATION
In situations where long range is not a requirement, a very
simple IR link can be made using unmodulated NRZ
(nonreturn to zero) data. The circuit is shown in Figure 5.
A BER (bit-error rate) transmitter and receiver was used to
test the data-link error rates for data rates of 375kbps.
Because the NRZ data can have long stretches of continu-
ous “1” data, the low frequency corner of the LT1328
photodiode receiver is set to 14Hz to prevent pulse-top
distortion.
To do this, make C1 4.7µF. This is the only change from
a standard IrDA-SIR receiver. A range of 24" (with a bit
error rate lower than 1 in 108) is achieved with no
additional processing beyond that provided by the LT1328.
A caution: when using unmodulated data, it is possible to
get a 100% duty cycle on the LED transmitter, so be sure
that the LED can handle this.
5V
24"
C5
4.7µF
R1
100Ω
R2
10k
D2
HSDL 4220
R3
3.9Ω
1/2W
Q3
2N7002
D1
TEMIC
BPV22NF
BIT ERROR RATE
TRANSMITTER/RECEIVER
375bps NRZ DATA
OUT
IN
1
8
2
7
3
LT1328
6
NC
C4
4
5
4.7µF
C6
1000pF
5V
C2
4.7µF
1328 F05
Figure 5. Simple NRZ Data Link
7
Share Link: 
