DS1284Q Equivalent & Substitute Parts

Part Overview

The DS1284Q is a Real Time Clock (RTC) IC with integrated Clock/Calendar functionality manufactured by Analog Devices Inc./Maxim Integrated. This parallel interface device provides 50 bytes of SRAM, alarm capability, leap year support, square wave output, and watchdog timer functionality. The DS1284Q operates with a supply voltage range of 4.5V to 5.5V and battery backup from 2.4V to 4.6V, with a maximum timekeeping current of 7mA at 5V.

The DS1284Q is classified as obsolete. Locating equivalent substitute parts becomes necessary when original inventory is depleted or when design revisions require components with improved availability, enhanced compliance status, or updated feature sets.

Substiute Parts

DS1284Q

Analog Devices Inc./Maxim IntegratedIn Stock: 2043DS1284Q Datasheet

Current PartRFQ

BQ4802LYDW

Texas InstrumentsIn Stock: 1993BQ4802LYDW Datasheet

MFR RecommendedRFQ

BQ4802YPW

Texas InstrumentsIn Stock: 1928BQ4802YPW Datasheet

MFR RecommendedRFQ

M48T201Y-70MH1F

STMicroelectronicsIn Stock: 2083M48T201Y-70MH1F Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the DS1284Q is determined by the following critical parameters:

Interface Compatibility: All substitute parts maintain parallel interface architecture, ensuring pin-level compatibility with existing circuit designs.

Voltage Supply Range: The DS1284Q operates at 4.5V ~ 5.5V primary supply. Substitute parts are grouped by their primary supply voltage specifications to ensure direct replacement capability without circuit modification.

Operating Temperature Range: All substitute parts maintain the 0°C ~ 70°C operating temperature range, matching the original specification.

Time and Date Format: Substitute parts support HH:MM:SS and YY-MM-DD date formats, maintaining functional equivalence for timekeeping applications.

Core Features: Alarm, Leap Year, and Watchdog Timer functionality are present across all substitute parts, preserving essential RTC capabilities.

Package Type: Surface mount packages are maintained across all substitutes. Package footprint differences (28-SOIC, 28-TSSOP, 44-BSOP) require PCB layout adaptation but do not affect electrical functionality.

Product Status and Compliance: Active product status and RoHS3 compliance of substitute parts provide improved long-term availability and regulatory alignment compared to the obsolete, non-compliant original part.

Parameter Comparison

Engineering Selection Recommendations

BQ4802LYDW (Texas Instruments): This substitute operates at a lower primary supply voltage range of 2.7V ~ 3.6V, making it suitable for applications requiring reduced power consumption. The timekeeping current is significantly lower at 1.5mA typical compared to the DS1284Q at 7mA. This part is active and RoHS3 compliant. PCB layout modification is required due to the 28-SOIC package transition from the original 28-LCC package.

BQ4802YPW (Texas Instruments): This substitute maintains the original 4.5V ~ 5.5V primary supply voltage range, providing direct voltage compatibility with the DS1284Q. Timekeeping current is reduced to 1.5mA typical. This part is active and RoHS3 compliant. The 28-TSSOP package requires PCB layout modification and represents the most compact footprint option among substitutes.

M48T201Y-70MH1F (STMicroelectronics): This substitute maintains the 4.5V ~ 5.5V primary supply voltage range and operates within the same temperature specification. The timekeeping current is 3mA at 4.5V ~ 5.5V, representing a moderate reduction from the original 7mA. This part is active and RoHS3 compliant. The 44-BSOP package requires significant PCB layout modification and necessitates a SNAPHAT connector. The Moisture Sensitivity Level of 3 (168 Hours) requires controlled storage conditions compared to the unlimited MSL of other options.

All three substitute parts provide improved product status (active versus obsolete) and regulatory compliance (RoHS3 compliant versus non-compliant), supporting long-term design sustainability and supply chain reliability.

Frequently Asked Questions (FAQ)

Q: Can BQ4802LYDW be used as a direct replacement for DS1284Q without circuit modification?

A: BQ4802LYDW maintains parallel interface compatibility and identical operating temperature range. However, the primary supply voltage range differs (2.7V ~ 3.6V versus 4.5V ~ 5.5V). Direct substitution requires circuit voltage adjustment. Additionally, the 28-SOIC package differs from the original 28-LCC package, requiring PCB layout modification.

Q: Which substitute part requires the least PCB layout modification?

A: BQ4802YPW in 28-TSSOP package represents the most compact footprint. However, all substitute parts require PCB layout adaptation due to package differences from the original 28-LCC. The specific degree of modification depends on the original PCB design and available routing space.

Q: What is the primary advantage of BQ4802YPW over BQ4802LYDW?

A: BQ4802YPW maintains the original 4.5V ~ 5.5V primary supply voltage range, eliminating the need for circuit voltage adjustment. Both parts offer identical timekeeping current specifications and RoHS3 compliance. The selection between these two depends on whether the application circuit operates at 4.5V ~ 5.5V or can accommodate the lower 2.7V ~ 3.6V range of BQ4802LYDW.

Q: Why does M48T201Y-70MH1F have a higher pin count (44-pin) compared to the original DS1284Q (28-pin)?

A: The M48T201Y-70MH1F is a different device architecture within the RTC Clock/Calendar category. The increased pin count reflects additional functionality and supervisor features. This substitute requires significant PCB redesign and is suitable only when the additional features and package form factor align with application requirements.

Q: What does Moisture Sensitivity Level (MSL) 3 mean for M48T201Y-70MH1F?

A: MSL 3 indicates a maximum floor life of 168 hours after moisture exposure. This part requires controlled storage conditions and careful handling during assembly compared to MSL 1 parts with unlimited floor life. Standard moisture control procedures during manufacturing must be observed.

Q: Are all substitute parts RoHS3 compliant?

A: Yes. BQ4802LYDW, BQ4802YPW, and M48T201Y-70MH1F are all RoHS3 compliant, providing regulatory alignment superior to the original DS1284Q, which is RoHS non-compliant. This compliance status supports long-term design certification and market acceptance.

Q: Can the DS1284Q be used interchangeably with these substitutes in existing designs?

A: No. Each substitute part requires design evaluation based on package compatibility, voltage supply requirements, and PCB layout constraints. The obsolete status of the DS1284Q makes forward migration to active substitute parts necessary for new production and long-term supply chain sustainability.