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National Semiconductor DS485 Low Power RS-485/RS-422 Multipoint Transceiver Data Sheet

Summary

This low-power transceiver is essential for building robust, multi-point data networks utilizing RS-485 and RS-422 differential signaling. Designed to meet TIA/EIA industry standards, it ensures reliable communication by operating from a single 5V supply while providing failsafe features and current limiting protection. The comprehensive manual details all necessary specifications—including electrical characteristics, absolute maximum ratings, and various packaging options—making it perfect for engineers developing industrial or commercial equipment that requires high-reliability, extended-range data bus connections connecting up to 32 transceivers.

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查询DS485供应商

Low ow er -485/R -422 ultipoint Transceiver

DS485 Low Power RS-485/RS-422 Multipoint Transceiver General Description Features

The DS485 is low-power transceiver for RS-485 and Meets TIA/EIA RS-485 multipoint standard

RS-422 communication. The device contains one driver and Guaranteed full load output voltage (V OD3) one receiver. The drivers slew rate allows for operation up to Low quiescent current: µA typ 2.5 Mbps (see Applications Information section). −7V to +12V common-mode input voltage range The transceiver draws µA of supply current when un- TRI-STATE outputs on driver and receiver loaded or fully loaded with the driver disabled and operates AC performance: from single +5V supply. Driver transition time: ns typ The driver is short-circuit current limited and is protected Driver propagation delay: ns typ against excessive power dissipation by thermal shutdown Driver skew: ns typ circuitry that places the driver outputs into TRI-STATE® Receiver propagation delay: ns typ

(High Impedance state) under fault conditions. The driver Receiver skew: ns typ

guarantees minimum of 1.5V differential output voltage Half-duplex flow through pinout with maximum loading across the common mode range Operates from single 5V supply (VOD3).

Allows up to transceivers on the bus

The receiver has failsafe feature that guarantees Current-limiting and thermal shutdown for driver logic-high output if the input is open circuit. overload protection The DS485 is available in surface mount and DIP packages Industrial temperature range operation and is characterized for Industrial and Commercial tempera- Pin and functional compatible with MAX485 and LTC485 ture range operation.

Connection and Logic Diagram Truth Table

DRIVER SECTION

DIP and SOIC

RE* DE DI

RECEIVER SECTION RE* DE A-B RO

DS012880-1

Order Number Temp. Range Package/###

OPEN*

DS485N 0˚C to +70˚C DIP/N08E

*Note: Non Terminated, Open Input only

DS485M 0˚C to +70˚C SOP/M08A indeterminate

TRI-STATE

DS485TN −40˚C to +85˚C DIP/N08E DS485TM −40˚C to +85˚C SOP/M08A

TRI-STATE® is registered trademark of National Semiconductor Corporation.

National Semiconductor Corporation DS012880 www.national.com

Page Summary Contents For National Semiconductor DS485 Low Power RS-485/RS-422 Multipoint Transceiver Data Sheet

Page 1 查询DS485供应商 Low ow er -485/R -422 ultipoint Transceiver DS485 Low Power RS-485/RS-422 Multipoint Transceiver General Description Features The DS485 is low-power transceiver for RS-485 and Meets TIA/EIA...
Page 2 Absolute Maximum Ratings (Note 1) Package 0.47W If Military/Aerospace specified devices are required, Storage Temperature Range −65˚C to +150˚C please contact the National Semiconductor Sales Office/ ...
Page 3 Switching Characteristics Over Supply Voltage and Operating Temperature Ranges, unless otherwise specified (Notes 3, 7, 8) Symbol Parameter Conditions Min Typ Max Units t PLHD Driver Differential Prop...
Page 4 Parameter Measurement Information DS012880-3 DS012880-2 FIGURE 5. VOD3 FIGURE 1. VOD DS012880-4 FIGURE 2. DS012880-5 FIGURE 6. DS012880-6 FIGURE 3. DS012880-7 FIGURE 7. DS012880-9 FIGURE 8. DS012880-8...
Page 5 Parameter Measurement Information (Continued) DS012880-10 FIGURE 9. DS012880-11 FIGURE 10. DS012880-12 FIGURE 11. DS012880-13 FIGURE 12. DS012880-14 FIGURE 13. www.national.com5
Page 6 Parameter Measurement Information (Continued) Pin Descriptions Pin I/O Name Function RO Receiver Output: If by m V, RO will be high; If by m V, RO will be low. RO will be high also if the inputs (A an...
Page 7 Applications Information The DS485 is low power transceiver designed for use in Due to the multipoint nature of the bus, contention between RS-485 multipoint applications. The DS485 can transmit drive...
Page 9 Physical Dimensions inches (millimeters) unless otherwise noted Order Number DS485M or DS485TM NS Package Number M08A Order Number DS485N or DS485TN NS Package Number N08E www.national.com9
Page 10 Lo ow er -4 /R -4 ul tip oi nt Tr an sc ei ve LIFE SUPPORT POLICY NATIONAL’S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT DE- VICES OR SYSTEMS WITHOUT THE EXPRESS WRITTEN...

Manual Details

Brand National
Pages 10
File Size 142.63 KB
Published June 15, 2026
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Frequently Asked Questions

What is the maximum number of transceivers allowed on the bus?

The DS485 allows up to 32 transceivers to be connected on a single bus.

What voltage range can I use for connection?

It supports a common-mode input voltage from -7V to +12V, and operates using a single 5V supply.

Is this device compatible with other standard models?

Yes, it is pin and functional compatible with popular transceivers like MAX485 and LTC485.

What is the low-power consumption if I don't need full load?

When fully disabled or unloaded, the transceiver draws a typical quiescent current of 200 μA.