DS8921ATMX/NOPB

Overview

The DS8921ATMX/NOPB is a differential line driver and receiver pair manufactured by Texas Instruments, housed in an SOIC-8 package. It operates on a single 4.5 V to 5.5 V supply with a typical quiescent current of 35 mA. The device features a typical propagation delay of 12 ns and an output skew of 0.5 ns. It supports RS-422 signaling standards with complementary driver outputs and a receiver input sensitivity of ±200 mV over a ±7 V common-mode range. The unit includes 70 mV typical hysteresis and functions within an industrial temperature range of -40°C to +85°C.

Feature Summary

• Provides differential drive capability for twisted-pair or parallel wire transmission lines
• Features high differential and common-mode input voltage ranges up to ±7 V
• Incorporates receiver input hysteresis to improve noise margins for slowly changing waveforms

Applications

• ST506 disk drive standard interfaces
• ST412 disk drive standard interfaces
• ESDI disk drive standard interfaces
• RS-422 interface applications

Procurement Notes

Verify the specific ordering suffix against the manufacturer's official documentation to confirm the exact package variant and temperature rating. Confirm RoHS compliance status and lead finish details directly from the datasheet addendum. Ensure the component matches the required industrial temperature specifications for the intended deployment environment before finalizing procurement orders.

Selection Notes

Select this component when designing systems requiring compatibility with legacy ST506, ST412, or ESDI disk drive standards alongside modern RS-422 interfaces. The industrial temperature grade (-40°C to +85°C) makes it suitable for harsh environments where commercial-grade parts would fail. Verify that the system power supply remains strictly within the 4.5 V to 5.5 V operating window to ensure signal integrity.

Part Context

This part belongs to the DS8921 family, which includes variants like the DS8921A and DS8921AT. The 'AT' designation specifically denotes the industrial temperature range extension compared to the commercial range of the base model. All variants share identical electrical characteristics and pinouts, differing primarily in their qualified operating temperature limits and specific manufacturing lot traceability.

Replacement Considerations

The DS8921AM/NOPB serves as a direct functional replacement if the application does not require operation below 0°C. Both devices share the same SOIC-8 package and electrical parameters. Designers must verify that the ambient temperature conditions remain above 0°C when substituting the commercial grade part for the industrial grade version.

FAQ

What is the maximum common-mode input voltage supported by the receiver?

The receiver supports a common-mode input voltage range of ±7 V.

How does the device handle noise on slowly changing input signals?

The receiver incorporates typical hysteresis of 70 mV to improve the noise margin for slowly changing input waveforms.

Is the driver output single-ended or differential?

The driver provides complementary differential outputs (DO+ and DO-) designed for driving twisted-pair or parallel wire transmission lines.