DS1021S-25

Overview

The DS1021S-25 is a programmable 8-bit silicon delay line manufactured by Analog Devices Inc./Maxim Integrated. It provides a total delay range of 73.75 ns with an incremental step size of 0.25 ns and an inherent step zero delay of 10 ns. The device operates on a single 4.75V to 5.25V supply within a commercial temperature range of 0°C to 70°C. It features TTL/CMOS compatibility, low-power CMOS construction, and edge accuracy for both rising and falling transitions. Configuration is supported via a 3-wire serial port or an 8-bit parallel interface in a 16-pin SOIC package.

Feature Summary

• Supports dual programming interfaces including a 3-wire serial port and an 8-bit parallel port for flexible system integration.
• Delivers precise timing control with equal steps across the full delay range and maintains accuracy on both leading and trailing signal edges.
• Enables cascading multiple units through a daisy-chain architecture using serial data output and input pins.

Applications

• Precision timing adjustment in digital logic circuits
• Programmable delay generation for test equipment
• Signal synchronization in communication systems

Procurement Notes

Verify component authenticity through authorized distributors or manufacturer channels. Confirm the specific -25 suffix indicates the 0.25 ns step model. Check RoHS compliance status as older batches may not meet current environmental standards. Validate package integrity upon receipt to ensure pin alignment matches the 16-SOIC specification.

Selection Notes

Select the DS1021S-25 when a maximum delay of 73.75 ns with 0.25 ns resolution is required. Choose the DS1021S-50 variant if a longer delay range up to 137.5 ns with 0.5 ns steps is needed. Ensure the design supports either serial or parallel programming constraints based on available microcontroller resources.

Part Context

This component belongs to the DS1021 family of programmable silicon delay lines. It serves as a CMOS alternative to hybrid delay lines, offering space-saving surface mount packaging. The series includes variants with different step resolutions to accommodate various timing precision requirements in electronic designs.

Replacement Considerations

DS1021S-50: Offers identical functionality with a 0.5 ns step size and 137.5 ns max delay.

FAQ

How is the delay value programmed?

The delay is set by configuring an 8-bit value via either the 3-wire serial port (pins D, C, S) or the 8-bit parallel port (pins P0-P7).

Can multiple DS1021 devices be connected together?

Yes, multiple devices can be daisy-chained by connecting the serial output (Q) of one unit to the serial input (D) of the next.

What is the inherent delay at step zero?

The DS1021 has an inherent step zero delay of 10 ns regardless of the programmed value.