multi-slave type of application where the number of slaves

exceeds 32, the DS481 may save in the cost of extra devices

like repeaters, extra media like cable, and/or extra compo-

nents like resistors.

Sleep Mode

The DS481 features an automatic sleep mode that allows

the device to save power when not transmitting data. Since

the sleep mode is automatic, no external components are re-

quired. It may be used as little or as much as the application

requires. The more the feature is utilized, the more power it

saves.

The sleep mode is automatically entered when both the

driver and receiver are disabled. This occurs when both the

DE pin is asserted to a logic low and the RE (Note 1) pin is

asserted to a logic high. Once both pins are asserted the de-

vice will enter sleep mode after 50 ns. The DS481 is guaran-

teed to go into sleep mode within 600 ns after both pins are

asserted. The device wakes up (comes out of sleep mode)

when either the DE pin is asserted to a logic high and/or the

RE (Note 1) pin is asserted to a logic low. After the device

enters sleep mode it will take longer for the device to wake

up than it does for the device to enable from TRI-STATE. Re-

fer to datasheet specifications t

with t

The benefit of the DS481 is definitely its power savings.

When active the device has a maximum I

When in sleep mode the device has a maximum I

10 µA, which is 50 times less power than when active. The

I

sleep mode the I

DS012919-16

FIGURE 15. Input Current vs Input Voltage

Operating Range

Multipoint RS-485 Application

DS012919-17

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