Avago Technologies ACPL-224-500E - Manual (Page 29)

AV02-4387EN 26 Avago Technologies
Data Communications Applications
Description
The HCNR200/1 Analog Optocoup-
ler isolates both the transmitter and
receiver circuit from the 4 - 20 mA
Analog Current Loop. One impor-
tant feature of this circuit is that the
loop side of the circuit is powered by
the loop current. No isolated power
supply is required.
Performance of Circuit
• Converts an analog voltage input
to an analog current and vice
versa
• HCNR200/1 nonlinearity: 0.1%
• HCNR201 gain tolerance: ±5%
Benefits
• Low­cost simple circuit
• No isolated power supply needed
on the 4 - 20 mA side of the circuit
Alternative Avago Parts
1) HCPL-4100 20 mA Current Loop
Transmitter
2) HCPL-4200 20 mA Current Loop
Receiver
Isolated 4-20 mA Analog Current Loop Transmitter/Receiver
A) RECEIVER
B) TRANSMITTER
8
7
6
1
3
HCNR200/201
5
2
4
LED
NC
NC
PD1 PD2
K1 K2
R3
25 Ω
R1
10k Ω
R2
10k Ω
HCNR200
PD1
0.001 µF
2N3906
LM158
Z1
5.1V
0.1 µF
HCNR200
LED
R4
180 Ω
-ILOOP
+ILOOP
+
–
HCNR200
PD 2
LM158
Vout
Vcc
5.5V
–
+
2
0.001 µF
R5
80k Ω
R3
10k Ω
R4
10k Ω
2N3904
2N3904
2N3906
LM158
2N3904
Z1
5.1V
HCNR200
PD 1
NOTE: The two OP-AMPS shown are two separate LM158, and NOT two channels in a single DUAL package;
otherwise, the LOOP saide and input sied will not be properly isolated.
HCNR200
LED
R2
150 Ω
R1
80k Ω
-ILOOP
+ILOOP
Vin
Vcc
5.5V
HCNR200
PD 2
R5
25 Ω
R7
3.2k Ω
R8
100k Ω
R6
140 Ω
–
+
0.001 µF
0.001 µF
0.1 µF
LM158
Vcc
–
+
1