HCPL-0720-500E Datasheet, PDF (17/18 Pages) AVAGO TECHNOLOGIES LIMITED – 40 ns Propagation Delay, CMOS Optocoupler

Power Supplies and Bypassing
The recommended DeviceNet application circuit is
shown in Figure 21. Since the HCPL-772X/072X are fully
compatible with CMOS logic level signals, the optocoup­
ler is connected directly to the CAN transceiver. Two by-
pass capacitors (with values between 0.01 and 0.1 µF)
are required and should be located as close as possible
to the input and output power-supply pins of the HCPL-
772X/072X. For each capacitor, the total lead length be-
tween both ends of the capacitor and the power supply
pins should not exceed 20 mm. The bypass capaci­tors
are required because of the high-speed digital nature of
the signals inside the optocoupler.
ISO 5 V
GALVANIC
ISOLATION
BOUNDARY
TX0
0.01 µF
1 VDD1
VDD2 8
2 VIN
3
HCPL-772x
HCPL-072x
7
VO 6
4 GND1
GND2 5
GND
RX0
0.01 µF
5 GND2
GND1 4
6 VO
7
HCPL-772x
HCPL-072x
3
VIN 2
0.01
µF
TxD
+
C4
0.01 µF
Rs
0.01
µF
5V
LINEAR OR
SWITCHING
REGULATOR
+
VCC
CANH
82C250
CANL
REF
RXD
GND
VREF
D1
30 V
8 VDD2
VDD1 1
ISO 5 V
5V
Figure 21. Recommended DeviceNet application circuit
+
5 V+
4 CAN+
3 SHIELD
2 CAN–
1 V–
C1
0.01 µF
500 V
R1
1M
Implementing PROFIBUS with the HCPL-772X/072X
An acronym for Process Fieldbus, PROFIBUS is essentially
a twisted-pair serial link very similar to RS-485 capable
of achieving high-speed communic­ ation up to 12 MBd.
As shown in Figure 22, a PROFIBUS Controll­er (PBC) es-
tablishes the connec­tion of a field automation unit (con-
trol or central processing station) or a field device to
the transmission medium. The PBC consists of the line
transceiver, optical isolation, frame character transmit-
ter/receiver (UART), and the FDL/APP processor with the
interface to the PROFIBUS user.
PROFIBUS USER:
CONTROL STATION
(CENTRAL PROCESSING)
OR FIELD DEVICE
USER INTERFACE
FDL/APP
PROCESSOR
UART
PBC
OPTICAL ISOLATION
TRANSCEIVER
MEDIUM
Figure 22. PROFIBUS Controller (PBC)
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