HCPL-0720-500E Avago Technologies US Inc., HCPL-0720-500E Datasheet - Page 16

• Manufacturer Part Number: HCPL-0720-500E
• Description: OPTOCOUPLER 25MBD 8NS 8-SOIC
• Manufacturer: Avago Technologies US Inc.

Specifications of HCPL-0720-500E

• Voltage - Isolation: 3750Vrms
• Number Of Channels: 1, Unidirectional
• Current - Output / Channel: 10mA
• Data Rate: 25MBd
• Propagation Delay High - Low @ If: 20ns
• Input Type: Logic
• Output Type: Push-Pull, Totem-Pole
• Mounting Type: Surface Mount
• Package / Case: 8-SOIC (0.154", 3.90mm Width)
• No. Of Channels: 1
• Optocoupler Output Type: Gate Drive
• Input Current: 10µA
• Output Voltage: 5V
• Opto Case Style: SOIC
• No. Of Pins: 8
• Input Current Max: 10mA
• Isolation Voltage: 3.75kV
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

DRAIN/SHIELD
Implementing DeviceNet and SDS with the HCPL-772X/072X
With transmission rates up to 1 Mbit/s, both DeviceNet
and SDS are based upon the same broadcast-oriented,
communica tions protocol — the Controller Area Network
(CAN). Three types of isolated nodes are recommended
for use on these networks: Isolated Node Powered by
the Network (Figure 18), Isolated Node with Transceiver
Powered by the Network (Figure 19), and Isolated Node
Providing Power to the Network (Figure 20).
Figure 18. Isolated node powered by the network.
Isolated Node with Transceiver Powered by the Network
Figure 19 shows a node powered by both the network
and another source. In this case, the trans ceiver and iso-
lated (network) side of the two optocouplers are pow-
ered by the network. The rest of the node is powered by
the AC line which is very beneficial when an application
requires a significant amount of power. This method is
also desirable as it does not heavily load the network.
More importantly, the unique “dual-inverting” design of
the HCPL-772X/072X ensure the network will not “lock-
up” if either AC line power to the node is lost or the node
powered-off. Specifically, when input power (V
HCPL-772X/072X located in the transmit path is eliminat-
ed, a RECESSIVE bus state is ensured as the HCPL-772X/
072X output voltage (V
16
SIGNAL
POWER
NETWORK
SUPPLY
POWER
772x/072x
NODE/APP SPECIFIC
HCPL
O
TRANSCEIVER
) go HIGH.
uP/CAN
772x/072x
HCPL
DD1
REG.
) to the
SWITCHING
ISOLATED
SUPPLY
POWER
Isolated Node Powered by the Network
This type of node is very flexible and as can be seen in
Figure 18, is regarded as “isolated” because not all of its
components have the same ground reference. Yet, all
compo nents are still powered by the network. This node
contains two regulators: one is isolated and powers the
CAN controller, node-specific application and isolated
(node) side of the two optocoup lers while the other is
non-isolated. The non-isolated regulator supplies the
transceiver and the non-isolated (network) half of the
two optocouplers.
*Bus V+ Sensing
It is suggested that the Bus V+ sense block shown in Fig-
ure 19 be implemented. A locally powered node with an
un-powered isolated Physical Layer will accumulate er-
rors and become bus-off if it attempts to transmit. The
Bus V+ sense signal would be used to change the BOI at-
tribute of the DeviceNet Object to the “auto-reset” (01)
value. Refer to Volume 1, Section 5.5.3. This would cause
the node to continually reset until bus power was detect-
ed. Once power was detected, the BOI attribute would
be returned to the “hold in bus-off” (00) value. The BOI
attribute should not be left in the “auto-reset” (01) value
since this defeats the jabber protection capability of the
CAN error confinement. Any inexpensive low frequency
optical isolator can be used to implement this feature.
V+ (SIGNAL)
V– (SIGNAL)
V+ (POWER)
V– (POWER)
GALVANIC
ISOLATION
BOUNDARY