DS1743-70+ Equivalent & Substitute Parts

Part Overview

The DS1743-70+ is a Real Time Clock (RTC) IC with integrated Clock/Calendar functionality and 8KB of Non-Volatile Static RAM (NVSRAM), manufactured by Analog Devices Inc./Maxim Integrated. This device operates in parallel interface mode and is packaged in a 28-DIP module format. The DS1743-70+ is classified as obsolete, making identification of functionally equivalent substitute components necessary for ongoing system support and new design implementations.

Substiute Parts

DS1743-70+

Analog Devices Inc./Maxim IntegratedIn Stock: 852DS1743-70+ Datasheet

Current PartRFQ

BQ3285S-SB2

Texas InstrumentsIn Stock: 1987BQ3285S-SB2 Datasheet

MFR RecommendedRFQ

BQ4802YDWR

Texas InstrumentsIn Stock: 1873BQ4802YDWR Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the DS1743-70+ is determined by the following critical parameters:

• Functional Equivalence: Clock/Calendar IC with parallel interface supporting 24-hour time format and YY-MM-DD-dd date format
• Electrical Compatibility: Supply voltage range of 4.5V ~ 5.5V and operating temperature range of 0°C ~ 70°C
• Interface Type: Parallel interface for direct pin-level compatibility
• Regulatory Compliance: ROHS3 compliance and EAR99 classification

The substitute parts identified (BQ3285S-SB2 and BQ4802YDWR) meet these core functional and electrical requirements. However, packaging differences exist: the main part uses Through Hole 28-DIP mounting, while substitutes use Surface Mount SOIC packages. This distinction requires circuit board redesign considerations.

Parameter Comparison

Engineering Selection Recommendations

BQ4802YDWR is the primary substitute for DS1743-70+ applications. This device maintains pin-count equivalence (28 pins) and supports the same parallel interface protocol. Both devices operate within identical supply voltage and temperature ranges. The BQ4802YDWR is in active production status with ROHS3 compliance and EAR99 classification, ensuring long-term availability and regulatory alignment.

BQ3285S-SB2 serves as an alternative substitute for applications where reduced pin count (24 pins) is acceptable. This device provides core Clock/Calendar functionality with parallel interface but requires circuit board redesign due to pin-count reduction and different SOIC package geometry.

Both substitutes are manufactured by Texas Instruments with active product status, providing superior long-term supply chain stability compared to the obsolete DS1743-70+.

Frequently Asked Questions (FAQ)

Q: Can BQ4802YDWR directly replace DS1743-70+ without circuit board modification?

A: BQ4802YDWR maintains 28-pin count and parallel interface compatibility. However, the package change from Through Hole 28-DIP to Surface Mount 28-SOIC requires circuit board redesign and adapter solutions for direct substitution.

Q: What are the key functional differences between DS1743-70+ and BQ4802YDWR?

A: Both devices provide Clock/Calendar functionality with parallel interface, 24-hour time format support, and identical supply voltage ranges (4.5V ~ 5.5V). BQ4802YDWR adds Alarm, Daylight Savings, Supervisor, and Watchdog Timer features not present in DS1743-70+.

Q: Is BQ3285S-SB2 suitable for DS1743-70+ replacement?

A: BQ3285S-SB2 provides Clock/Calendar functionality with parallel interface and compatible electrical specifications. The 24-pin SOIC package requires significant circuit board redesign compared to the original 28-DIP configuration.

Q: Are both substitute parts ROHS3 compliant?

A: Yes. DS1743-70+, BQ3285S-SB2, and BQ4802YDWR are all ROHS3 compliant with EAR99 classification.

Q: What is the primary consideration when selecting between BQ3285S-SB2 and BQ4802YDWR?

A: Pin count and package footprint are the primary differentiators. BQ4802YDWR (28-SOIC) maintains pin-count equivalence with the original DS1743-70+, while BQ3285S-SB2 (24-SOIC) requires pin-mapping redesign.