DS1642-70 Equivalent & Substitute Parts

Part Overview

The DS1642-70 is a Real Time Clock (RTC) IC with integrated Clock/Calendar functionality and 2KB of Non-Volatile Static RAM (NVSRAM). Manufactured by Analog Devices Inc./Maxim Integrated, this component operates in the 4.5V to 5.5V supply range and provides parallel interface connectivity with 24-hour time format and YY-MM-DD-dd date format support. The device is packaged in a 24-DIP Module (0.600", 15.24mm) through-hole configuration.

The DS1642-70 is classified as obsolete. Identifying equivalent substitute parts is necessary to maintain design continuity, ensure component availability, and support ongoing production or maintenance requirements for systems utilizing this RTC functionality.

Substiute Parts

DS1642-70

Analog Devices Inc./Maxim IntegratedIn Stock: 3748DS1642-70 Datasheet

Current PartRFQ

BQ4802YDW

BenchmarqIn Stock: 1824BQ4802YDW Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the DS1642-70 is determined by the following critical parameters:

• Functional Type: Clock/Calendar RTC with parallel interface capability
• Supply Voltage Compatibility: 4.5V ~ 5.5V operating range
• Time and Date Format Support: HH:MM:SS (24 hr) and YY-MM-DD-dd formats
• Operating Temperature Range: 0°C ~ 70°C
• Interface Type: Parallel connectivity

The BQ4802YDW qualifies as a substitute based on matching supply voltage range (4.5V ~ 5.5V), parallel interface, compatible time format support (12/24 hr selectable), matching date format (YY-MM-DD-dd), and overlapping operating temperature range (0°C ~ 70°C). The BQ4802YDW is classified as Active product status, ensuring ongoing availability and support.

Parameter Comparison

Engineering Selection Recommendations

The DS1642-70 is obsolete, making the BQ4802YDW the primary substitute option based on functional and electrical compatibility. Both devices operate within the 4.5V to 5.5V supply range, support parallel interface architecture, and maintain compatible time/date format specifications across the 0°C to 70°C operating temperature window.

The BQ4802YDW offers Active product status, ensuring continued manufacturer support, availability, and compliance with current industry standards. The BQ4802YDW provides additional features including alarm functionality, daylight savings support, supervisor, and watchdog timer capabilities not present in the DS1642-70.

Primary design consideration: The BQ4802YDW uses Surface Mount (28-SOIC) packaging versus the DS1642-70 Through Hole (24-DIP Module) configuration. PCB layout and assembly process modifications are required to accommodate this packaging transition.

Frequently Asked Questions (FAQ)

Q: Can the BQ4802YDW directly replace the DS1642-70 without firmware changes?

A: Both devices support parallel interface, matching supply voltage (4.5V ~ 5.5V), and compatible time/date formats (HH:MM:SS and YY-MM-DD-dd). Register-level compatibility must be verified against specific firmware implementation. The BQ4802YDW includes additional features (alarm, supervisor, watchdog timer) not present in the DS1642-70; these features do not interfere with basic clock/calendar operation if unused.

Q: What are the packaging implications of substitution?

A: The DS1642-70 is Through Hole (24-DIP Module, 0.600" width), while the BQ4802YDW is Surface Mount (28-SOIC, 0.295" width). PCB redesign is required to accommodate the different package footprint, pin count, and assembly process (reflow soldering versus wave soldering).

Q: Are there supply voltage differences that affect circuit design?

A: Both devices operate within 4.5V to 5.5V supply range. The BQ4802YDW includes battery backup capability (2.4V ~ 4V), which the DS1642-70 does not specify. If battery backup is required, the BQ4802YDW provides this functionality; if not required, standard 5V supply operation is identical between both devices.

Q: How do timekeeping current specifications compare?

A: The DS1642-70 draws 3mA maximum at 5V during timekeeping. The BQ4802YDW draws 1.5mA typical at 4.5V to 5.5V, representing lower power consumption. This difference may impact battery backup duration if backup power is implemented.

Q: Are both devices RoHS compliant?

A: The DS1642-70 is RoHS non-compliant. Compliance status for the BQ4802YDW is not provided in the available specifications. Verify RoHS compliance requirements against current procurement standards before final component selection.