DS1721U Equivalent & Substitute Parts

Part Overview

The DS1721U is a digital temperature sensor manufactured by Analog Devices Inc./Maxim Integrated, designed for local temperature measurement across the -55°C to 125°C range with 11-bit resolution and I2C output. The device operates on a 2.7V to 5.5V supply and features programmable limits, one-shot capability, and standby mode functionality. The DS1721U is currently classified as obsolete, making identification of functionally equivalent alternatives essential for ongoing system support and new design implementations.

Substiute Parts

DS1721U

Analog Devices Inc./Maxim IntegratedIn Stock: 1610DS1721U Datasheet

Current PartRFQ

DS1721U+

Analog Devices Inc./Maxim IntegratedIn Stock: 2368DS1721U+ Datasheet

DirectRFQ

TCN75-3.3MUA

Microchip TechnologyIn Stock: 1281TCN75-3.3MUA Datasheet

MFR RecommendedRFQ

TCN75-3.3MUA713

Microchip TechnologyIn Stock: 1955TCN75-3.3MUA713 Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution for the DS1721U is determined by the following critical parameters: operating temperature range (-55°C to 125°C), I2C communication protocol, surface mount packaging (8-TSSOP/8-MSOP), supply voltage compatibility (2.7V to 5.5V), and digital local temperature sensing capability.

The substitute parts identified maintain these core functional requirements. However, resolution and accuracy specifications differ among alternatives, which must be evaluated against application requirements. The DS1721U+ represents a direct form-fit-function replacement from the same manufacturer with identical electrical specifications but improved product status and RoHS compliance. The TCN75 series alternatives from Microchip Technology provide equivalent temperature range and I2C interface but operate at reduced resolution (8-bit versus 11-bit) and lower accuracy (±3°C versus ±1°C).

Parameter Comparison

Engineering Selection Recommendations

For applications requiring direct replacement with identical electrical performance and pin compatibility, the DS1721U+ is the primary substitute. This part maintains the 11-bit resolution and ±1°C accuracy of the original DS1721U while offering active product status and ROHS3 compliance, eliminating obsolescence and regulatory concerns.

For applications where reduced resolution and accuracy are acceptable, the TCN75-3.3MUA and TCN75-3.3MUA713 provide functionally equivalent alternatives from Microchip Technology. Both variants maintain the full -55°C to 125°C operating range, I2C interface, and 8-TSSOP/8-MSOP packaging. The primary difference between these two TCN75 variants is packaging format: TCN75-3.3MUA is supplied in tube packaging, while TCN75-3.3MUA713 is supplied in cut tape and Digi-Reel format. Both are ROHS3 compliant and carry active product status.

Selection between DS1721U+ and TCN75 alternatives should be based on application tolerance requirements. Applications demanding the original ±1°C accuracy specification require the DS1721U+. Applications tolerating ±3°C accuracy can utilize either TCN75 variant based on packaging and supply chain requirements.

Frequently Asked Questions (FAQ)

Q: Can the TCN75-3.3MUA directly replace the DS1721U without firmware changes?

A: The TCN75-3.3MUA maintains I2C protocol compatibility and identical package footprint (8-TSSOP/8-MSOP). However, the reduced resolution (8-bit versus 11-bit) and lower accuracy (±3°C versus ±1°C) may require application-level tolerance verification. Register mapping and command structures should be reviewed against specific implementation requirements.

Q: What is the difference between TCN75-3.3MUA and TCN75-3.3MUA713?

A: Both parts are electrically and functionally identical. The difference is packaging format: TCN75-3.3MUA is supplied in tube packaging, while TCN75-3.3MUA713 is supplied in cut tape and Digi-Reel format. Selection depends on assembly process requirements and supply chain logistics.

Q: Why is the DS1721U classified as obsolete?

A: The DS1721U has reached end-of-life status from the manufacturer. The DS1721U+ provides an active alternative with identical specifications and improved compliance status.

Q: Are all substitute parts RoHS compliant?

A: The DS1721U is RoHS non-compliant. The DS1721U+, TCN75-3.3MUA, and TCN75-3.3MUA713 are all ROHS3 compliant, meeting current regulatory requirements for new designs and applications subject to RoHS directives.

Q: What are the key parameters that determine substitution compatibility?

A: Operating temperature range (-55°C to 125°C), I2C communication interface, surface mount package type (8-TSSOP/8-MSOP), supply voltage range (2.7V to 5.5V), and digital local temperature sensing capability are the primary parameters defining substitution compatibility. Resolution and accuracy specifications must be evaluated against application-specific requirements.