DS1501WE Equivalent & Substitute Parts

Part Overview

The DS1501WE is a Real Time Clock (RTC) IC with Clock/Calendar functionality manufactured by Analog Devices Inc./Maxim Integrated. This 28-TSSOP surface mount device provides 256 bytes of parallel interface memory with integrated timekeeping, alarm, leap year compensation, NVSRAM, square wave output, and watchdog timer capabilities. The DS1501WE is classified as obsolete, making equivalent substitute parts necessary for new designs and ongoing production requirements.

Substiute Parts

DS1501WE

Analog Devices Inc./Maxim IntegratedIn Stock: 2992DS1501WE Datasheet

Current PartRFQ

BQ4802YDWR

Texas InstrumentsIn Stock: 1873BQ4802YDWR Datasheet

MFR RecommendedRFQ

M48T02-70PC1

STMicroelectronicsIn Stock: 1276M48T02-70PC1 Datasheet

MFR RecommendedRFQ

M48T58Y-70MH1F

STMicroelectronicsIn Stock: 2289M48T58Y-70MH1F Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the DS1501WE requires matching on the following critical parameters:

Primary Substitution Criteria:

• Parallel interface architecture
• Clock/Calendar functionality with 24-hour time format and YY-MM-DD-dd date format
• Surface mount packaging with compatible pin count and footprint
• Operating temperature range of 0°C ~ 70°C
• Alarm and leap year compensation features
• Supply voltage compatibility within acceptable ranges

Secondary Considerations:

• Memory capacity (256B minimum)
• Timekeeping current consumption
• Battery backup voltage support
• RoHS compliance status for new designs
• Moisture sensitivity level

The DS1501WE has three identified equivalent substitutes: BQ4802YDWR (Texas Instruments), M48T02-70PC1 (STMicroelectronics), and M48T58Y-70MH1F (STMicroelectronics). Each substitute maintains core parallel interface RTC functionality but differs in packaging, voltage specifications, and compliance certifications.

Parameter Comparison

Engineering Selection Recommendations

BQ4802YDWR (Texas Instruments): This substitute is active in production with ROHS3 compliance and unlimited moisture sensitivity rating. The 28-SOIC surface mount package maintains compatibility with surface mount assembly processes. Supply voltage operates at 4.5V ~ 5.5V, requiring voltage regulation if the original 3V ~ 3.6V supply is used. Current consumption is lower at 1.5mA typical. The BQ4802YDWR includes daylight savings and supervisor features not present in the DS1501WE. This option is suitable for new designs requiring RoHS compliance and active manufacturer support.

M48T02-70PC1 (STMicroelectronics): This substitute operates as an active product with ROHS3 compliance. The 24-DIP through-hole package represents a significant form factor change from the surface mount DS1501WE, requiring PCB redesign. Supply voltage is 4.75V ~ 5.5V. This option is appropriate only when through-hole assembly is preferred or when existing PCB layouts accommodate DIP packaging. The reduced feature set (leap year only) may limit functional compatibility.

M48T58Y-70MH1F (STMicroelectronics): This substitute is active in production with ROHS3 compliance and maintains the 28-SOIC surface mount package format. Supply voltage is 4.5V ~ 5.5V with 3mA timekeeping current. The MSL rating of 3 (168 Hours) matches the DS1501WE. This option provides the closest form factor compatibility while offering active product status and RoHS compliance. The Timekeeper® series designation indicates manufacturer continuity.

Frequently Asked Questions (FAQ)

Q: Can the DS1501WE be directly replaced with BQ4802YDWR without PCB modification?

A: The BQ4802YDWR uses a 28-SOIC package compared to the DS1501WE's 28-TSSOP package. While both are 28-pin surface mount devices, the pin pitch and footprint dimensions differ. PCB layout modification is required. Additionally, the supply voltage range differs (4.5V ~ 5.5V vs. 3V ~ 3.6V), necessitating power supply adjustment.

Q: What are the key functional differences between the substitute parts?

A: The BQ4802YDWR includes daylight savings and supervisor features absent in the DS1501WE. The M48T02-70PC1 offers minimal features (leap year only) and uses through-hole packaging. The M48T58Y-70MH1F maintains surface mount compatibility with reduced feature set compared to the DS1501WE.

Q: Why is the DS1501WE classified as obsolete?

A: The DS1501WE is no longer manufactured by Analog Devices Inc./Maxim Integrated. Existing inventory may be available through authorized distributors, but new production is not supported. Active alternatives must be evaluated for new designs.

Q: Are all substitute parts RoHS compliant?

A: Yes, all three substitute parts (BQ4802YDWR, M48T02-70PC1, and M48T58Y-70MH1F) are ROHS3 compliant. The original DS1501WE is RoHS non-compliant, making substitution necessary for applications requiring RoHS certification.

Q: What is the impact of different supply voltage ranges?

A: The DS1501WE operates at 3V ~ 3.6V, while all substitutes require 4.5V ~ 5.5V (or 4.75V ~ 5.5V for M48T02-70PC1). Designs using the DS1501WE at 3.3V logic levels must incorporate voltage regulation or level shifting to accommodate the higher supply voltage requirements of substitute parts.

Q: Does package selection affect timekeeping accuracy?

A: Package type (TSSOP, SOIC, DIP) does not affect timekeeping accuracy. All parts maintain the same operating temperature range (0°C ~ 70°C) and date/time format specifications. Package selection is driven by PCB assembly process and form factor constraints.

Q: What is the significance of MSL (Moisture Sensitivity Level) ratings?

A: The DS1501WE and M48T58Y-70MH1F both have MSL 3 (168 Hours), requiring controlled storage and handling. The BQ4802YDWR and M48T02-70PC1 have MSL 1 (Unlimited), allowing indefinite storage without moisture control. MSL affects component shelf life and handling procedures during manufacturing.