DS1553P-70 Equivalent & Substitute Parts

Part Overview

The DS1553P-70 is a Real Time Clock (RTC) IC with integrated Clock/Calendar functionality, 8KB NVSRAM, and parallel interface from Analog Devices Inc./Maxim Integrated. This component is classified as obsolete, making equivalent substitute parts necessary for new designs and ongoing system support. The DS1553P-70 operates in the 4.5V to 5.5V supply range with battery backup at 3V and includes features such as alarm capability, leap year compensation, and watchdog timer functionality. Due to its obsolete status, identifying compatible alternatives is essential for procurement and design continuity.

Substiute Parts

DS1553P-70

Analog Devices Inc./Maxim IntegratedIn Stock: 724DS1553P-70 Datasheet

Current PartRFQ

BQ3285S-SB2

Texas InstrumentsIn Stock: 1987BQ3285S-SB2 Datasheet

MFR RecommendedRFQ

M48T12-150PC1

STMicroelectronicsIn Stock: 2537M48T12-150PC1 Datasheet

MFR RecommendedRFQ

M48T18-150PC1

STMicroelectronicsIn Stock: 1310M48T18-150PC1 Datasheet

MFR RecommendedRFQ

M48T35AV-10PC1

STMicroelectronicsIn Stock: 1390M48T35AV-10PC1 Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the DS1553P-70 is determined by the following critical parameters:

Primary Compatibility Criteria:

• Parallel interface requirement
• 24-hour time format support
• YY-MM-DD-dd date format support
• Operating temperature range 0°C ~ 70°C
• Supply voltage compatibility (4.5V ~ 5.5V primary or 3V ~ 3.6V alternative)
• RTC with Clock/Calendar functionality

Substitution Logic: The DS1553P-70 can be replaced by parts meeting the core functional requirements of parallel-interface RTC Clock/Calendar operation within the specified voltage and temperature ranges. Substitute parts are grouped by mounting type (Surface Mount vs. Through Hole) and package configuration, as these determine physical and electrical compatibility with existing circuit designs. Memory size variations and feature differences (such as watchdog timer presence) are secondary considerations when primary electrical parameters align.

Parameter Comparison

Engineering Selection Recommendations

BQ3285S-SB2 (Texas Instruments): This part maintains surface mount compatibility with the DS1553P-70 and operates within the same 4.5V to 5.5V supply range. It is actively manufactured and ROHS3 compliant, addressing regulatory requirements that the obsolete DS1553P-70 does not meet. The 24-SOIC package differs from the 34-PowerCap™ Module, requiring PCB redesign. This option is suitable for new designs prioritizing regulatory compliance and active manufacturer support.

M48T12-150PC1 (STMicroelectronics): This through-hole 24-DIP package RTC operates at 4.5V to 5.5V with 24-hour time format and YY-MM-DD-dd date format support. It is actively produced and ROHS3 compliant. The through-hole mounting and DIP package require different PCB footprints than the surface-mount DS1553P-70. This option is appropriate for legacy system repairs where through-hole technology is already established.

M48T18-150PC1 (STMicroelectronics): This through-hole 28-DIP package RTC provides parallel interface operation at 4.5V to 5.5V with watchdog timer functionality matching the DS1553P-70 feature set. It is actively manufactured and ROHS3 compliant. The 28-pin DIP package requires PCB redesign from the 34-pin PowerCap™ Module. This option is suitable for applications requiring watchdog timer capability in through-hole form factor.

M48T35AV-10PC1 (STMicroelectronics): This through-hole 28-DIP package RTC operates at the reduced voltage range of 3V to 3.6V, making it suitable only for systems designed for low-voltage operation. It is actively produced and ROHS3 compliant. Selection of this part requires confirmation that the system power supply and all interfacing circuits support the 3V to 3.6V range. This option is not recommended as a direct replacement for 5V systems.

Frequently Asked Questions (FAQ)

Q: Can the BQ3285S-SB2 directly replace the DS1553P-70 without PCB modification?

A: No. The BQ3285S-SB2 uses a 24-SOIC surface-mount package, while the DS1553P-70 uses a 34-PowerCap™ Module package. PCB redesign is required. However, both operate at 4.5V to 5.5V with parallel interface and 24-hour time format, making functional substitution possible with layout changes.

Q: Why are the STMicroelectronics M48T series parts through-hole when the DS1553P-70 is surface mount?

A: The M48T series represents the Timekeeper® family of RTC devices, which are manufactured in DIP through-hole packages. These parts provide functional equivalence in parallel interface, voltage range, and time/date format, but require different PCB mounting technology. Surface-mount alternatives like the BQ3285S-SB2 are available if surface-mount form factor is required.

Q: Is the M48T35AV-10PC1 suitable for replacing the DS1553P-70 in a 5V system?

A: No. The M48T35AV-10PC1 operates at 3V to 3.6V supply voltage, while the DS1553P-70 requires 4.5V to 5.5V. This part is only suitable for systems specifically designed for low-voltage operation. Use M48T12-150PC1 or M48T18-150PC1 for 5V system compatibility.

Q: What is the primary advantage of selecting an active product status substitute?

A: Active products have ongoing manufacturer support, documented availability, and compliance with current regulatory standards such as ROHS3. The DS1553P-70 is obsolete, meaning manufacturer support has ended and future availability is uncertain. All substitute parts listed are actively manufactured.

Q: Do all substitute parts support the same memory size as the DS1553P-70?

A: No. The DS1553P-70 provides 8KB memory. The BQ3285S-SB2 provides 114B memory. The M48T series parts do not specify memory size in the provided data. Memory capacity differences may affect application suitability depending on data storage requirements.

Q: Can the DS1553P-70 be replaced in a design that requires watchdog timer functionality?

A: Yes. The M48T18-150PC1 includes watchdog timer functionality matching the DS1553P-70 feature set. The BQ3285S-SB2 and M48T12-150PC1 do not include this feature. Verify watchdog timer requirements before selecting a substitute.