hcpl-4100500 Avago Technologies, hcpl-4100500 Datasheet - Page 10

• Manufacturer Part Number: hcpl-4100500
• Description: Optically Coupled 20 Ma Current Loop Transmitter
• Manufacturer: Avago Technologies

Figure 13. Recommended Non-Isolated Active Receiver with HCPL-4100 Isolated Transmitter for Simplex Point to Point 20 mA Current Loop.
25% distortion data rate at different V
tion data rate is defined as that rate at which 25% distortion
occurs to output bit interval with respect to the input bit
interval. Maximum data rate (dotted line) is restricted by
device characteristics. An input Non-Return-to-Zero (NRZ)
test waveform of 16 bits (0000001011111101) was used
for data rate distortion measurements. Enhanced speed
performance of the loop system can be obtained with lower
V
when loop current is supplied through a resistor instead
of by a current source, an additional series termination
resistance equal to the characteristic line impedance can
be used at the HCPL-4100 transmitter end to enhance
speed of response by approximately 20%.
Figure 14. Minimum Required Supply Voltage, V
Loop Length for Current Loop Circuit of Figure 13.
10
CC
supply levels, as illustrated in Figure 15. In addition,
40
36
32
28
24
20
16
12
8
4
0
L – LOOP LENGTH (ONE DIRECTION) METERS
0
V
R
I
V
V
T
LOOP
CC
MARK
SAT
A
CABLE
= 25 °C
= 0.00212
= 1.5 Vdc (CURRENT SOURCE)
= 20 mA
= 2.7 Vdc (HCPL-4100)
= 0.05296
100
— (L) + 5.7 V
m
V
Ω /m
1000
CC
, vs.
10000
CC
values. 25% distor-
The cable used contained five pairs of unshielded, twisted,
22 AWG wire (Dearborn #862205). Loop current is 20 mA
nominal. Input and output logic supply voltages are 5 V
dc.
Full Duplex
The full duplex point-to-point communication of Fig-
ure 16 uses a four wire system to provide simultane-
ous, bidirectional data communication between local
and remote equipment. The basic application uses
two simplex point-to-point loops which have two
separate, active, non-isolated units at one common
end of the loops. The other end of each loop is isolated.
Figure 15. Typical Data Rate vs. Distance and Supply
Voltage.