DS1643P-70 Equivalent & Substitute Parts

Part Overview

The DS1643P-70 is a Real Time Clock (RTC) IC with integrated Clock/Calendar functionality and 8KB NVSRAM, manufactured by Analog Devices Inc./Maxim Integrated. This Surface Mount device operates in the 4.5V to 5.5V supply range with battery backup at 3V and supports 24-hour time format with leap year capability. The DS1643P-70 is classified as Obsolete, making equivalent substitute parts necessary for new designs and ongoing production requirements. Substitute parts must maintain compatibility across parallel interface architecture, supply voltage specifications, and core RTC/Calendar functionality.

Substiute Parts

DS1643P-70

Analog Devices Inc./Maxim IntegratedIn Stock: 974DS1643P-70 Datasheet

Current PartRFQ

BQ4802YDW

BenchmarqIn Stock: 1824BQ4802YDW Datasheet

MFR RecommendedRFQ

DP8573AVX/NOPB

National SemiconductorIn Stock: 1484DP8573AVX/NOPB Datasheet

MFR RecommendedRFQ

M48T02-150PC1

STMicroelectronicsIn Stock: 1525M48T02-150PC1 Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution logic for the DS1643P-70 is based on the following critical parameters that determine functional compatibility:

Primary Substitution Criteria:

• Parallel interface architecture (mandatory for pin-level compatibility)
• Supply voltage range: 4.5V ~ 5.5V (primary operation)
• Battery backup voltage support (minimum 2.2V acceptable)
• Clock/Calendar functionality with date and time tracking
• 24-hour time format capability
• Operating temperature range overlap: 0°C ~ 70°C minimum

Secondary Considerations:

• Leap year support (feature parity)
• Surface Mount or Through Hole mounting (application-dependent)
• Current consumption during timekeeping operation
• Package form factor (determines PCB layout compatibility)

The three substitute parts identified—BQ4802YDW, DP8573AVX/NOPB, and M48T02-150PC1—meet the primary substitution criteria through parallel interface design, compatible supply voltage specifications, and RTC/Calendar functionality. Each substitute maintains the core electrical and functional parameters required for drop-in or design-level replacement scenarios.

Parameter Comparison

Engineering Selection Recommendations

BQ4802YDW (Benchmarq): Active product status with Surface Mount 28-SOIC packaging. Maintains 4.5V ~ 5.5V supply voltage compatibility and parallel interface architecture. Supports 12/24-hour time format with extended battery voltage range (2.4V ~ 4V). Lower typical timekeeping current (1.5mA) compared to DS1643P-70. Suitable for new designs requiring Surface Mount form factor with active manufacturer support.

DP8573AVX/NOPB (National Semiconductor): Active product status with Surface Mount 28-LCC (J-Lead) packaging. Maintains 4.5V ~ 5.5V supply voltage and parallel interface. Offers extended operating temperature range (-40°C ~ 85°C) and superior battery voltage range (2.2V ~ 5.1V). Lowest timekeeping current consumption (1µA @ 5V). Recommended for applications requiring extended temperature operation or minimal power consumption during battery backup mode.

M48T02-150PC1 (STMicroelectronics): Active product status with Through Hole 24-DIP packaging. Maintains 4.75V ~ 5.5V supply voltage and parallel interface. ROHS3 compliant with unlimited moisture sensitivity level (MSL 1). Identical timekeeping current specification (3mA) to DS1643P-70. Suitable for legacy Through Hole PCB designs or applications requiring RoHS compliance. Part of the Timekeeper® series with established field reliability.

Frequently Asked Questions (FAQ)

Q: Can BQ4802YDW replace DS1643P-70 in existing designs? A: BQ4802YDW maintains parallel interface and 4.5V ~ 5.5V supply voltage compatibility. However, package form factor differs (28-SOIC vs. 34-PowerCap™ Module), requiring PCB layout redesign. Functional compatibility is confirmed for RTC/Calendar operation.

Q: What is the primary difference between DP8573AVX/NOPB and DS1643P-70? A: DP8573AVX/NOPB offers extended operating temperature range (-40°C ~ 85°C vs. 0°C ~ 70°C) and significantly lower timekeeping current (1µA vs. 3mA @ 5V). Both maintain parallel interface and compatible supply voltage specifications. Package form factor differs (28-LCC vs. 34-PowerCap™ Module).

Q: Is M48T02-150PC1 suitable for Surface Mount applications? A: No. M48T02-150PC1 uses Through Hole 24-DIP packaging, requiring DIP socket or through-hole PCB traces. This part is appropriate for legacy designs or applications where Through Hole mounting is specified.

Q: Do all substitute parts support 24-hour time format? A: BQ4802YDW and DP8573AVX/NOPB support both 12-hour and 24-hour formats. M48T02-150PC1 supports 24-hour format only, matching DS1643P-70 specification.

Q: Which substitute part has the best RoHS compliance status? A: M48T02-150PC1 is ROHS3 compliant. BQ4802YDW and DP8573AVX/NOPB RoHS status is not specified in available documentation.

Q: Can these parts be used interchangeably without firmware changes? A: All substitute parts maintain parallel interface architecture and compatible date/time format (YY-MM-DD-dd). However, register mapping and command protocols may differ. Firmware validation is required for each specific substitution scenario.