DS1689SN Equivalent & Substitute Parts

Part Overview

The DS1689SN 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 support and dual voltage supply operation (2.7V–3.3V and 4.5V–5.5V). The product is currently obsolete, making equivalent substitute parts necessary for ongoing system support, maintenance, and new design implementations requiring compatible RTC functionality.

Substiute Parts

DS1689SN

Analog Devices Inc./Maxim IntegratedIn Stock: 8996DS1689SN Datasheet

Current PartRFQ

BQ4802YDW

BenchmarqIn Stock: 1824BQ4802YDW Datasheet

MFR RecommendedRFQ

M48T02-150PC1

STMicroelectronicsIn Stock: 1525M48T02-150PC1 Datasheet

MFR RecommendedRFQ

M48T35AV-10MH1F

STMicroelectronicsIn Stock: 5879M48T35AV-10MH1F Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the DS1689SN is determined by the following critical parameters:

Primary Compatibility Criteria:

• Interface type: Parallel
• Time format support: HH:MM:SS (12/24 hr)
• Date format support: YY-MM-DD-dd
• Mounting type: Surface Mount
• Package type: 28-pin SOIC or compatible 28-pin surface mount variant
• Voltage supply ranges: Overlap with 4.5V–5.5V or 2.7V–3.3V operation

Secondary Compatibility Factors:

• Operating temperature range
• Current consumption during timekeeping
• Product status (Active status preferred for new designs)
• RoHS compliance status

The substitute parts identified (BQ4802YDW, M48T02-150PC1, M48T35AV-10MH1F) meet the core functional and electrical requirements for Clock/Calendar operation with parallel interface. However, variations in package dimensions, mounting technology, voltage specifications, and temperature ranges require engineering evaluation based on specific application constraints.

Parameter Comparison

Engineering Selection Recommendations

BQ4802YDW (Benchmarq): Active product status with 28-SOIC surface mount package and parallel interface. Supports 12/24-hour time format and YY-MM-DD-dd date format. Operates within 4.5V–5.5V supply range with lower typical timekeeping current (1.5mA). Operating temperature range limited to 0°C–70°C. Suitable for applications not requiring extended temperature operation below 0°C or above 70°C.

M48T02-150PC1 (STMicroelectronics): Active product with Timekeeper® series designation and ROHS3 compliance. Through-hole 24-DIP package requires PCB layout modification from the original 28-SOIC surface mount design. Parallel interface with 24-hour time format and YY-MM-DD-dd date format. Operates within 4.75V–5.5V supply range. Suitable for legacy system retrofits or applications where through-hole mounting is preferred.

M48T35AV-10MH1F (STMicroelectronics): Active product with Timekeeper® series designation and ROHS3 compliance. 28-SOP surface mount package with SNAPHAT socket interface. Operates within 3V–3.6V supply range with 2mA timekeeping current. 24-hour time format and YY-MM-DD-dd date format. Operating temperature range 0°C–70°C. Suitable for low-voltage applications and direct pin-compatible replacement where voltage specifications align.

Frequently Asked Questions (FAQ)

Q: Can BQ4802YDW directly replace DS1689SN in existing designs?

A: BQ4802YDW provides functional equivalence for Clock/Calendar operation with parallel interface, 12/24-hour time format, and YY-MM-DD-dd date format. Both devices use 28-SOIC surface mount packages. However, package dimensions differ (BQ4802YDW: 0.295" vs. DS1689SN: 0.337" width), and operating temperature range is limited to 0°C–70°C versus DS1689SN's -40°C–85°C. Voltage supply is restricted to 4.5V–5.5V. Verify application temperature and voltage requirements before substitution.

Q: Why is M48T02-150PC1 listed as a substitute if it uses a different package?

A: M48T02-150PC1 provides functional Clock/Calendar equivalence with parallel interface and matching date/time formats. The 24-DIP through-hole package represents a different mounting technology requiring PCB redesign. This substitute is applicable for legacy system maintenance or applications where through-hole mounting is acceptable. New surface mount designs should prioritize BQ4802YDW or M48T35AV-10MH1F.

Q: What are the key differences between BQ4802YDW and M48T35AV-10MH1F?

A: BQ4802YDW operates at 4.5V–5.5V supply voltage with 1.5mA typical timekeeping current. M48T35AV-10MH1F operates at 3V–3.6V supply voltage with 2mA timekeeping current. BQ4802YDW supports 12/24-hour time format; M48T35AV-10MH1F supports 24-hour format only. Both use surface mount packages and support YY-MM-DD-dd date format. Select based on system voltage requirements and time format compatibility.

Q: Are all substitute parts RoHS compliant?

A: M48T02-150PC1 and M48T35AV-10MH1F are ROHS3 compliant. BQ4802YDW RoHS status is not specified in available documentation. The original DS1689SN is RoHS non-compliant. Verify RoHS compliance requirements for your application before final part selection.

Q: What is the impact of operating temperature range differences?

A: DS1689SN operates from -40°C to 85°C. All substitute parts operate from 0°C to 70°C. Applications requiring operation below 0°C or above 70°C cannot use these substitutes. Verify your system's thermal environment and operating specifications before substitution.

Q: Can these parts be used interchangeably in the same PCB layout?

A: No. BQ4802YDW and M48T35AV-10MH1F use different 28-pin SOIC variants with different package dimensions. M48T02-150PC1 uses a 24-pin DIP package. PCB footprint verification and potential layout modification are required. Consult package datasheets for exact pin assignments and mechanical dimensions.