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 classified as obsolete, making identification of functionally equivalent alternatives necessary for ongoing system maintenance and new design implementations where legacy compatibility is required.

Substiute Parts

DS1642-70+

Analog Devices Inc./Maxim IntegratedIn Stock: 875DS1642-70+ 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 Category: Clock/Calendar RTC IC with parallel interface
• 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
• Interface Type: Parallel communication protocol
• Operating Temperature Range: 0°C ~ 70°C
• Regulatory Compliance: ROHS3 Compliant, REACH Affected, EAR99 classification

The BQ4802YDW from Benchmarq meets these core functional requirements while offering enhanced features including alarm capability, daylight savings support, supervisor function, and watchdog timer. The substitute maintains voltage compatibility and operating temperature specifications while providing parallel interface operation.

Parameter Comparison

Engineering Selection Recommendations

The BQ4802YDW serves as a functional equivalent for the DS1642-70+ based on the following engineering criteria:

Voltage and Timing Compatibility: Both devices operate within the 4.5V to 5.5V supply range and support the required 24-hour time format with YY-MM-DD-dd date format. The BQ4802YDW additionally supports 12-hour format operation, providing operational flexibility.

Parallel Interface Continuity: Both components utilize parallel interface architecture, maintaining signal protocol compatibility with existing system designs.

Product Status and Availability: The DS1642-70+ is classified as obsolete, while the BQ4802YDW maintains active product status with documented inventory availability (1782 pieces in stock). This status differential makes the BQ4802YDW the appropriate selection for new implementations and ongoing system support.

Regulatory Compliance: Both devices carry identical ECCN (EAR99) and HTSUS (8542.39.0001) classifications, ensuring consistent export and tariff treatment.

Package Consideration: The substitution requires transition from 24-DIP through-hole mounting to 28-SOIC surface-mount packaging. This change necessitates PCB layout modification and assembly process adjustment.

Frequently Asked Questions (FAQ)

Q: Can the BQ4802YDW directly replace the DS1642-70+ without circuit modification?

A: Functional replacement is possible due to matching supply voltage (4.5V ~ 5.5V), parallel interface operation, and time/date format support. However, the package transition from 24-DIP to 28-SOIC requires PCB redesign and assembly process changes. Pin-to-pin compatibility must be verified against specific application schematics.

Q: What is the significance of the mounting type difference?

A: The DS1642-70+ uses through-hole DIP mounting for breadboard and traditional PCB assembly, while the BQ4802YDW employs surface-mount SOIC packaging for automated assembly processes. This difference affects PCB layout, assembly equipment requirements, and soldering methodology.

Q: Does the BQ4802YDW provide equivalent memory capacity?

A: The DS1642-70+ specifies 2KB NVSRAM. The BQ4802YDW memory size is not specified in the provided parameters. Memory capacity verification against application requirements is necessary before substitution.

Q: What is the advantage of the BQ4802YDW's lower timekeeping current?

A: The BQ4802YDW operates at 1.5mA typical current compared to the DS1642-70+'s 3mA maximum, representing a 50% reduction in power consumption during timekeeping operation. This improvement benefits battery-backed applications and reduces thermal load.

Q: Are both devices subject to the same regulatory requirements?

A: Yes. Both the DS1642-70+ and BQ4802YDW share identical ECCN (EAR99) and HTSUS (8542.39.0001) classifications, indicating equivalent regulatory treatment for export control and tariff purposes.