DS1284 Equivalent & Substitute Parts

Part Overview

The DS1284 is a Real Time Clock (RTC) IC with Clock/Calendar functionality manufactured by Analog Devices Inc./Maxim Integrated. This 28-DIP through-hole component provides 50 bytes of SRAM, alarm capability, leap year support, square wave output, and watchdog timer functionality. The DS1284 is classified as obsolete, making equivalent substitute parts necessary for ongoing system maintenance, repairs, and legacy product support. Substitute parts must maintain compatibility with the parallel interface, 28-DIP package footprint, and core timing/calendar functionality while meeting modern compliance standards.

Substiute Parts

DS1284

Analog Devices Inc./Maxim IntegratedIn Stock: 1162DS1284 Datasheet

Current PartRFQ

M48T02-70PC1

STMicroelectronicsIn Stock: 1276M48T02-70PC1 Datasheet

MFR RecommendedRFQ

M48T08Y-10MH1F

STMicroelectronicsIn Stock: 1165M48T08Y-10MH1F Datasheet

MFR RecommendedRFQ

M48T35Y-70PC1

STMicroelectronicsIn Stock: 3110M48T35Y-70PC1 Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the DS1284 is determined by the following critical parameters:

Primary Compatibility Criteria:

• Interface type: Parallel (required)
• Package mounting: Through Hole (required for direct PCB replacement)
• Supply voltage range: 4.5V ~ 5.5V (required for circuit compatibility)
• Operating temperature: 0°C ~ 70°C (required)
• Clock/Calendar functionality (required)

Secondary Considerations:

• Package form factor: 28-DIP preferred for direct footprint compatibility
• RoHS compliance status: Modern substitutes should meet ROHS3 compliance
• Product status: Active status preferred for long-term availability

The three qualified substitutes meet the primary criteria with varying package configurations and compliance improvements. M48T35Y-70PC1 provides the closest form factor match (28-DIP through-hole). M48T02-70PC1 uses a 24-DIP module package. M48T08Y-10MH1F transitions to surface mount (28-SOP) technology.

Parameter Comparison

Engineering Selection Recommendations

M48T35Y-70PC1 is the primary substitute for direct replacement applications. This part maintains the 28-DIP through-hole package footprint, matching the DS1284 pinout and PCB layout without modification. It operates within the required 4.5V ~ 5.5V supply range, supports the parallel interface, and achieves ROHS3 compliance. The active product status ensures long-term availability. Current consumption is reduced to 2mA, providing improved power efficiency compared to the DS1284's 7mA specification.

M48T02-70PC1 serves as an alternative for applications where pin-count reduction is acceptable. The 24-DIP module package requires PCB layout modification but maintains through-hole mounting and the same 0.600" pitch. Supply voltage range is slightly narrower (4.75V ~ 5.5V minimum). This part is suitable for new designs or retrofit applications with design flexibility.

M48T08Y-10MH1F is appropriate for modernized designs transitioning to surface-mount technology. The 28-SOP package reduces board space and improves manufacturing efficiency. This part requires PCB redesign and surface-mount assembly capability. Moisture sensitivity level MSL-3 requires controlled storage conditions (168-hour floor life limit after moisture exposure).

All three substitutes provide ROHS3 compliance, addressing the DS1284's non-compliance status. Selection should prioritize M48T35Y-70PC1 for legacy system repairs requiring minimal PCB modification.

Frequently Asked Questions (FAQ)

Q: Can M48T02-70PC1 replace DS1284 without PCB modification? A: No. M48T02-70PC1 uses a 24-DIP module package versus the DS1284's 28-DIP package. Pin count and footprint differ, requiring PCB layout changes. This substitute is suitable for new designs or applications with design flexibility.

Q: Is M48T35Y-70PC1 a direct pin-for-pin replacement? A: M48T35Y-70PC1 maintains the 28-DIP through-hole package and operates within the DS1284's supply voltage range (4.5V ~ 5.5V). Both support parallel interface and clock/calendar functionality. Verify specific pinout compatibility with application schematics before implementation, as feature sets differ (M48T35Y-70PC1 supports leap year; DS1284 includes alarm and square wave output).

Q: Why does M48T08Y-10MH1F have higher moisture sensitivity? A: M48T08Y-10MH1F uses surface-mount technology (28-SOP package), which typically exhibits higher moisture sensitivity (MSL-3, 168-hour floor life) compared to through-hole packages (MSL-1, unlimited). This requires controlled storage and handling procedures during assembly.

Q: What is the impact of reduced current consumption in substitute parts? A: M48T02-70PC1, M48T08Y-10MH1F, and M48T35Y-70PC1 consume 2-3mA during timekeeping operation, compared to DS1284's 7mA. This reduction improves power efficiency and reduces thermal load, benefiting battery-backed and low-power applications.

Q: Are all substitutes RoHS compliant? A: Yes. M48T02-70PC1, M48T08Y-10MH1F, and M48T35Y-70PC1 are ROHS3 compliant. The DS1284 is RoHS non-compliant. Substitution addresses regulatory compliance requirements for new production and updated designs.

Q: Which substitute is recommended for legacy system repair? A: M48T35Y-70PC1 is recommended for legacy system repair. It provides direct 28-DIP through-hole package compatibility, matching the DS1284 footprint and requiring no PCB modification. Active product status ensures availability for ongoing support.