3
DEMO MANUAL DC112A
REFERENCE
DESIGNATOR
QUANTITY
PART NUMBER
DESCRIPTION
VENDOR
TELEPHONE
C1
1
12065C103KATMA
0.01
µ
F 50V 20% X7R Capacitor
AVX
(803) 946-0362
C2
1
12065C104KATMA
0.1
µ
F 50V 10% X7R Capacitor
AVX
(803) 946-0362
C3
1
TAJC106K016R
10
µ
F 16V 10% Tantalum Capacitor
AVX
(207) 282-5111
C4
1
1206A331KATMA
330pF 50V 10% NPO Capacitor
AVX
(803) 946-0362
C6
1
12065C102KATMA
1000pF 50V 10% X7R Capacitor
AVX
(803) 946-0362
D1
1
BPV22NF
Diode
Temic
(408) 970-5700
D2
1
HSDL-4220
LED
Hewlett Packard
(800) 235-0312
E1 to E6
6
1502-2
Turret
Keystone
(718) 956-8900
JP1
1
3801S-3-G1
3-Pin Header
COMM CON
(818) 301-4200
Q1, Q2
2
2N7002LTA
Transistor
Zetex
(516) 543-7100
R1
1
CR32-101J-T
100
Ω
5% Resistor
AVX
(803) 946-0524
R2
1
CR32-103J-T
10k 5% Resistor
AVX
(803) 946-0524
R3
1
CRCW20106R8J
6.8
Ω
1/2W 5%
Dale
(408) 985-5733
U1
1
LT1328CS8
IC
LTC
(408) 432-1900
XJP1
1
CCIJ230-G
Shunt
COMM CON
(818) 301-4200
PARTS LIST
OPERATIO
U
The most straightforward way of evaluating IR links with
the LT1328 demo board is to have a separate LED trans-
mitter, like that on DC112A, that can be placed a measured
distance from the receiver. If a second board is not
available, it is a simple matter to duplicate the transmitter
design shown in the schematic diagram (Figure 2). The
pulses to drive this transmitter can be obtained from a
suitable pulse generator that has a TTL output or from the
system that will use the IR link, if available. Use coax cable
and place a suitable termination on the input of the
transmitter board to ensure good pulse fidelity.
The onboard jumper must be set for the modulation
desired. The position of this jumper is marked on the demo
board. For example, for IrDA-SIR modulation, set the
mode jumper to the SIR side.
Connect an oscilloscope to the appropriate output of the
demonstration board and apply a 5V power source capable
of supplying greater than 25mA to the V
CC
and either GND
pin (both ground pins are common).
Set the transmitter close to the receiver (
≈
1cm), input an
appropriate modulation signal to the trans input pin and
verify the basic operation of the receiver using the modu-
lation photographs (Figures 3, 4 and 5) as a guide.
You can then test the receiver over the desired range,
transmitter power, angle of incidence or other variables. It
is helpful to set up a space for an optical range that is clear
of obstacles, reflections and interference. Later, when the
basic operation of the IR link is established, the receiver
can be tested against any interference that the final system
may encounter. For more sophisticated testing, a Bit Error
Rate Test (BERT) set is usually required, as are the circuits
to modulate and demodulate the digital signals.
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