DS481TM National Semiconductor, DS481TM Datasheet - Page 7

• Manufacturer Part Number: DS481TM
• Description: IC, TXRX, RS485/422, W/SLEEP, 8SOIC
• Manufacturer: National Semiconductor

Specifications of DS481TM

• Device Type: Line Driver / Receiver
• No. Of Drivers: 1
• Supply Voltage Range: 4.75V To 5.25V
• Driver Case Style: SOIC
• No. Of Pins: 8
• Operating Temperature Range: -40°C To +85°C
• Svhc: No SVHC
• Interface Type: RS422, RS485
• Rohs Compliant: Yes
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Unit Load
The advantage of the
of nodes on one bus. In a single master 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 components like resis-
tors.
Sleep Mode
The DS481 features an automatic sleep mode that allows
the device to save power when not transmitting data. Since
FIGURE 15. Input Current vs Input Voltage
(Continued)
Operating Range
1
⁄
2
UL device is the increased number
Multipoint RS-485 Application
01291916
7
the sleep mode is automatic, no external components are
required. It may be used as little or as much as the applica-
tion 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
device will enter sleep mode after 50 ns. The DS481 is
guaranteed 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. Refer to datasheet specifications t
compare 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
Applications Information
CC
when the device is active is already very low but when in
PZL
CC
and t
is ultra low.
PZH
for timing differences.
PSL
CC
and t
01291917
www.national.com
of 500 µA.
CC
PSH
of only
and