DS1687-5IND Real Time Clock IC Equivalent & Substitute Parts

Part Overview

The DS1687-5IND is a Real Time Clock (RTC) IC with integrated Clock/Calendar functionality, manufactured by Analog Devices Inc./Maxim Integrated. This 24-DIP through-hole module provides 242 bytes of NVSRAM, alarm capability, square wave output, and Y2K compliance. The part is currently classified as obsolete, making equivalent and substitute parts necessary for ongoing system support and new design implementations. Active alternatives with compatible electrical and mechanical specifications are available from multiple manufacturers.

Substiute Parts

DS1687-5IND

Analog Devices Inc./Maxim IntegratedIn Stock: 1009DS1687-5IND Datasheet

Current PartRFQ

DS1687-5IND+

Analog Devices Inc./Maxim IntegratedIn Stock: 2010DS1687-5IND+ Datasheet

DirectRFQ

BQ4802LYDWR

Texas InstrumentsIn Stock: 3828BQ4802LYDWR Datasheet

MFR RecommendedRFQ

M48T58-70PC1

STMicroelectronicsIn Stock: 1546M48T58-70PC1 Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution for the DS1687-5IND is determined by the following critical parameters:

Primary Compatibility Criteria:

• Parallel interface for direct pin-level compatibility
• Clock/Calendar functionality with HH:MM:SS and YY-MM-DD-dd format support
• Real Time Clock with alarm capability
• Operating voltage range overlap or compatibility with 4.5V ~ 5.5V supply
• Through-hole or surface-mount packaging with equivalent pin count and signal mapping

Substitute Categories:

1. Direct Equivalent (DS1687-5IND+): Identical electrical specifications and package format. Differs only in product status (active vs. obsolete) and RoHS compliance. Packaging upgraded to tube format.

2. Functional Equivalent with Package Variation (BQ4802LYDWR): Texas Instruments RTC with parallel interface, clock/calendar functionality, and compatible time/date formats. Differs in package type (28-SOIC surface mount vs. 24-DIP through hole), operating temperature range (0°C ~ 70°C vs. -40°C ~ 85°C), and supply voltage (2.7V ~ 3.6V vs. 4.5V ~ 5.5V). Enhanced features include daylight savings, leap year, supervisor, and watchdog timer.

3. Functional Equivalent with Package Variation (M48T58-70PC1): STMicroelectronics RTC with parallel interface, clock/calendar functionality, and compatible time/date formats. Differs in package type (28-DIP vs. 24-DIP), operating temperature range (0°C ~ 70°C vs. -40°C ~ 85°C), and supply voltage (4.75V ~ 5.5V vs. 4.5V ~ 5.5V). Timekeeper® series designation.

Parameter Comparison

Engineering Selection Recommendations

DS1687-5IND+ (Direct Equivalent): Use this part for direct replacement in existing designs. Maintains identical electrical specifications and 24-DIP through-hole package format. Offers active product status and ROHS3 compliance, eliminating obsolescence and regulatory concerns while preserving pin-for-pin compatibility.

M48T58-70PC1 (Through-Hole Alternative): Select this part for through-hole designs requiring active product status and ROHS3 compliance. Maintains 28-DIP package format compatible with through-hole assembly. Operating temperature range is limited to 0°C ~ 70°C; verify compatibility with application requirements. Supply voltage range (4.75V ~ 5.5V) is narrower than the original part; confirm power supply specifications.

BQ4802LYDWR (Surface-Mount Alternative): Use this part for new designs or redesigns incorporating surface-mount technology. Provides active product status and ROHS3 compliance. Requires PCB layout modification due to 28-SOIC package format. Operating temperature range is limited to 0°C ~ 70°C; verify compatibility with application requirements. Supply voltage range (2.7V ~ 3.6V) differs significantly from the original part; circuit redesign may be necessary.

Frequently Asked Questions (FAQ)

Q: Can DS1687-5IND+ be used as a direct replacement for DS1687-5IND?

A: Yes. DS1687-5IND+ is electrically and mechanically identical to DS1687-5IND. Both use 24-DIP through-hole packaging with identical pin assignments, voltage specifications (4.5V ~ 5.5V), and functional parameters. The primary difference is product status (active vs. obsolete) and RoHS compliance (ROHS3 vs. non-compliant).

Q: What are the key differences between DS1687-5IND and BQ4802LYDWR?

A: The primary differences are package type (24-DIP through-hole vs. 28-SOIC surface mount), operating temperature range (−40°C ~ 85°C vs. 0°C ~ 70°C), and supply voltage (4.5V ~ 5.5V vs. 2.7V ~ 3.6V). BQ4802LYDWR includes additional features (daylight savings, leap year, supervisor, watchdog timer) and lower timekeeping current (1.5mA typical vs. 3mA maximum). Pin-level compatibility requires verification and potential circuit redesign.

Q: Is M48T58-70PC1 compatible with the original DS1687-5IND design?

A: M48T58-70PC1 maintains through-hole mounting and parallel interface compatibility. However, the package is 28-DIP (vs. 24-DIP), requiring PCB layout modification. Operating temperature range is limited to 0°C ~ 70°C. Supply voltage range (4.75V ~ 5.5V) is narrower. Pin-level signal mapping must be verified before implementation.

Q: Which substitute part is recommended for new designs?

A: DS1687-5IND+ is recommended for designs requiring direct compatibility with existing layouts. For new designs, evaluate M48T58-70PC1 (through-hole) or BQ4802LYDWR (surface mount) based on assembly technology, operating temperature requirements, and supply voltage specifications.

Q: Are all substitute parts RoHS compliant?

A: DS1687-5IND is RoHS non-compliant. DS1687-5IND+, BQ4802LYDWR, and M48T58-70PC1 are all ROHS3 compliant. All substitute parts are REACH unaffected, whereas the original DS1687-5IND is REACH affected.

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

A: DS1687-5IND operates from −40°C ~ 85°C. BQ4802LYDWR and M48T58-70PC1 operate from 0°C ~ 70°C. Applications requiring operation below 0°C or above 70°C must use DS1687-5IND or DS1687-5IND+. Verify application temperature requirements before selecting a substitute part.

Q: Can BQ4802LYDWR be used in a through-hole design?

A: No. BQ4802LYDWR uses 28-SOIC surface-mount packaging. Through-hole designs require DS1687-5IND+, M48T58-70PC1, or equivalent through-hole packages. Surface-mount conversion requires PCB redesign and assembly process modification.