HCPL-0720-500E Datasheet, PDF (16/18 Pages) AVAGO TECHNOLOGIES LIMITED – 40 ns Propagation Delay, CMOS Optocoupler

NODE/APP SPECIFIC
µP/CAN
HCPL
772x/072x
HCPL
772x/072x
TRANSCEIVER
AC LINE
NON ISO
5V
*HCPL
772x/072x
REG.
GALVANIC
ISOLATION
BOUNDARY
DRAIN/SHIELD
SIGNAL
POWER
V+ (SIGNAL)
V– (SIGNAL)
V+ (POWER)
V– (POWER)
NETWORK
POWER
SUPPLY
* OPTIONAL FOR BUS V + SENSE
Figure 19. Isolated node with transceiver powered by the network.
Isolated Node Providing Power to the Network
Figure 20 shows a node providing power to the network.
The AC line powers a regulator which provides 5 V local-
ly. The AC line also powers a 24 V isolated supply, which
powers the network, and another 5 V regulator, which, in
turn, powers the transceiver and isolated (network) side
of the two optocouplers. This method is recommended
when there is a limited number of devices on the net-
work, which do not require much power, thus eliminat-
ing the need for separate power supplies.
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_DD1) to the
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_O) go HIGH.
DeviceNet Node
NODE/APP SPECIFIC
µP/CAN
HCPL
772x/072x
HCPL
772x/072x
TRANSCEIVER
AC LINE
5 V REG.
5 V REG.
ISOLATED
SWITCHING
POWER
SUPPLY
GALVANIC
ISOLATION
BOUNDARY
DRAIN/SHIELD
SIGNAL
POWER
Figure 20. Isolated node providing power to the network.
16
V+ (SIGNAL)
V– (SIGNAL)
V+ (POWER)
V– (POWER)