DS485M/NOPB

Overview

The DS485M/NOPB is a low-power RS-485/RS-422 multipoint transceiver manufactured by Texas Instruments. It integrates one driver and one receiver, supporting data rates up to 2.5 Mbps with a typical driver transition time of 25 ns. The device operates from a single +5V supply (4.75V to 5.25V) and draws a typical quiescent current of 200 μA. It features a wide common-mode input voltage range of -7V to +12V and ensures a minimum differential output voltage of 1.5V under full load conditions. The component includes short-circuit current limiting and thermal shutdown protection for the driver. It is available in an 8-pin SOIC package and supports up to 32 transceivers on the bus.

Feature Summary

• Low power consumption with typical quiescent current of 200 μA
• Wide common-mode input voltage range from -7V to +12V
• Integrated thermal shutdown and short-circuit protection for driver overload
• Failsafe receiver feature ensuring logic-high output when inputs are open

Applications

• Multipoint RS-485 communication networks
• RS-422 point-to-point or multipoint links
• Industrial control systems requiring robust noise immunity
• Building automation and security systems

Procurement Notes

Verify the specific ordering suffix to confirm the package type and temperature rating. The 'M' suffix indicates an 8-pin SOIC package. Confirm that the 'NOPB' designation aligns with RoHS compliance requirements. Check the official datasheet for the most recent lifecycle status, as this part may be subject to discontinuation notices. Ensure the selected variant matches the required operating temperature range for the application environment.

Selection Notes

Select the DS485M/NOPB for applications requiring standard unit loads on RS-485 buses where up to 32 nodes are needed. This component is suitable for designs operating at data rates up to 2.5 Mbps. Consider the thermal shutdown feature if the application involves potential bus contention or short circuits. Verify that the 8-pin SOIC package fits the PCB layout constraints. Compare against related parts like the DS36C278 series if lower power or higher node counts are required.

Part Context

The DS485 is part of Texas Instruments' low-power RS-485 transceiver family. It is pin and functionally compatible with the MAX485 and LTC485, facilitating direct replacements in existing designs. The device is characterized for operation within the industrial temperature range. Related components in the series include the DS36C278 and DS36C279, which offer ultra-low power consumption and support for up to 128 transceivers on the bus.

Replacement Considerations

The DS485 is pin and functionally compatible with the MAX485 and LTC485. Designers can replace these components with the DS485M/NOPB without modifying the circuit layout or logic connections. Verify that the replacement part meets the specific temperature and packaging requirements of the original design.