DS1689S+ Equivalent & Substitute Parts

Part Overview

The DS1689S+ is a Real Time Clock (RTC) IC with integrated Clock/Calendar functionality manufactured by Analog Devices Inc./Maxim Integrated. This 28-SOIC surface mount device provides 114 bytes of NVSRAM with parallel interface, supporting dual voltage supplies (2.7V–3.3V and 4.5V–5.5V) and battery backup operation. The product is classified as obsolete, making equivalent and substitute parts necessary for ongoing system support and new design implementations.

Substiute Parts

DS1689S+

Analog Devices Inc./Maxim IntegratedIn Stock: 1018DS1689S+ Datasheet

Current PartRFQ

BQ4802YDW

BenchmarqIn Stock: 1824BQ4802YDW Datasheet

MFR RecommendedRFQ

BQ4845S-A4TR

Texas InstrumentsIn Stock: 910BQ4845S-A4TR Datasheet

MFR RecommendedRFQ

M48T02-150PC1

STMicroelectronicsIn Stock: 1525M48T02-150PC1 Datasheet

MFR RecommendedRFQ

M48T08-100PC1

STMicroelectronicsIn Stock: 1683M48T08-100PC1 Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution for the DS1689S+ is determined by the following critical parameters:

Primary Substitution Criteria:

• Interface type: Parallel
• Time format: HH:MM:SS (12/24 hr)
• Date format: YY-MM-DD-dd
• Operating temperature range: 0°C ~ 70°C
• Package compatibility: 28-SOIC or equivalent pinout

Secondary Compatibility Factors:

• Voltage supply ranges (primary and battery)
• Current consumption during timekeeping
• RoHS and compliance certifications
• Product status (active vs. obsolete)

The substitute parts listed below maintain functional equivalence through matching interface protocols, time/date format support, and operating temperature specifications. Package variations (28-SOIC vs. 24-DIP/28-DIP) represent mechanical alternatives suitable for different PCB assembly requirements.

Parameter Comparison

Engineering Selection Recommendations

Surface Mount Alternatives (28-SOIC): BQ4802YDW and BQ4845S-A4TR maintain the surface mount form factor of the DS1689S+. Both are active products with parallel interface and matching time/date format support. BQ4845S-A4TR carries ROHS3 compliance and MSL-1 rating, aligning with the original part's environmental certifications. BQ4802YDW offers lower typical timekeeping current (1.5mA vs. 3mA @ 5V) but lacks specified RoHS status.

Through Hole Alternatives (DIP): M48T02-150PC1 (24-DIP) and M48T08-100PC1 (28-DIP) provide through-hole mounting for applications requiring different PCB assembly methods. Both are active STMicroelectronics products with ROHS3 compliance and MSL-1 rating. These parts support 24-hour time format only (not 12/24 hr switchable) and do not specify battery supply voltage ranges. M48T08-100PC1 includes watchdog timer functionality.

Compliance Considerations: All substitute parts maintain ROHS3 compliance and MSL-1 moisture sensitivity ratings. BQ4845S-A4TR and both STMicroelectronics parts carry REACH unaffected status. Product status transitions from obsolete (DS1689S+) to active for all substitutes, ensuring long-term availability and manufacturing support.

Frequently Asked Questions (FAQ)

Q: Can BQ4802YDW or BQ4845S-A4TR directly replace DS1689S+ in existing designs? A: Both parts maintain parallel interface, matching time/date formats, and identical operating temperature range. Pinout compatibility must be verified against the original schematic. The 28-SOIC package dimensions differ slightly (0.295" vs. 0.337" width), but both are standard 28-SOIC footprints suitable for SMD assembly.

Q: What is the primary difference between the two surface mount substitutes? A: BQ4845S-A4TR (Texas Instruments) provides ROHS3 compliance and MSL-1 certification matching the DS1689S+. BQ4802YDW (Benchmarq) offers lower typical timekeeping current consumption but lacks specified RoHS status. Both support 12/24-hour time format switching.

Q: Why do M48T02-150PC1 and M48T08-100PC1 specify only 24-hour time format? A: These STMicroelectronics Timekeeper® series parts operate exclusively in 24-hour format. Applications requiring 12-hour format support must use BQ4802YDW or BQ4845S-A4TR.

Q: Are the DIP packages suitable for new designs? A: M48T02-150PC1 and M48T08-100PC1 are active products with current manufacturing support. Through-hole mounting is appropriate for applications prioritizing manual assembly, rework capability, or legacy PCB designs. Surface mount alternatives (BQ4802YDW, BQ4845S-A4TR) are recommended for modern high-density PCB layouts.

Q: What battery voltage range should be considered for system design? A: DS1689S+ supports 2.5V–3.7V battery supply. BQ4802YDW and BQ4845S-A4TR support 2.4V–4V and 2.3V–4V respectively, providing broader compatibility with standard lithium coin cell batteries. M48T02-150PC1 and M48T08-100PC1 do not specify battery supply voltage.

Q: Are all substitutes RoHS3 compliant? A: BQ4845S-A4TR, M48T02-150PC1, and M48T08-100PC1 carry explicit ROHS3 compliance certification. BQ4802YDW does not specify RoHS status in available documentation.