DS1501WSN+ Equivalent & Substitute Parts

Part Overview

The DS1501WSN+ is a Real Time Clock (RTC) IC with integrated Clock/Calendar functionality, manufactured by Analog Devices Inc./Maxim Integrated. This device provides 256 bytes of parallel interface memory with comprehensive timekeeping features including alarm, leap year compensation, NVSRAM, square wave output, and watchdog timer capabilities. The part is classified as obsolete, making equivalent substitute components necessary for new designs and ongoing system support.

Substiute Parts

DS1501WSN+

Analog Devices Inc./Maxim IntegratedIn Stock: 1170DS1501WSN+ Datasheet

Current PartRFQ

BQ4802LYPWR

Texas InstrumentsIn Stock: 28912BQ4802LYPWR Datasheet

MFR RecommendedRFQ

M48T35AV-10PC1

STMicroelectronicsIn Stock: 1390M48T35AV-10PC1 Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the DS1501WSN+ is determined by the following critical parameters:

Interface Compatibility: The main part uses a parallel interface. Substitute parts must maintain parallel interface architecture to ensure direct functional replacement without firmware or protocol modifications.

Package and Mounting: The DS1501WSN+ uses a 28-SOIC surface mount package. Substitutes may use alternative surface mount packages (28-TSSOP) or through-hole packages (28-DIP) depending on application requirements and PCB layout constraints.

Voltage Specifications: Supply voltage range (3V ~ 3.6V) and battery backup voltage (2.5V ~ 3.7V) define the power supply compatibility window. Substitute parts must support overlapping or equivalent voltage ranges.

Time and Date Format: Both the main part and substitutes support 24-hour time format and YY-MM-DD-dd date format, ensuring calendar functionality alignment.

Core Features: Alarm functionality, leap year compensation, and watchdog timer are essential features present in the main part. Substitute parts must provide equivalent or superior feature sets.

Temperature Range: The DS1501WSN+ operates across -40°C ~ 85°C. Substitutes with narrower temperature ranges (0°C ~ 70°C) are acceptable for applications within that reduced range.

Compliance: RoHS3 compliance and MSL Level 1 rating are maintained across all substitute options.

Parameter Comparison

Engineering Selection Recommendations

BQ4802LYPWR (Texas Instruments): This substitute is an active product with superior timekeeping current efficiency (1.5mA typical versus 4mA maximum for the main part). The 28-TSSOP package provides a smaller footprint than the original 28-SOIC. Supply voltage range extends to 2.7V, offering broader low-voltage compatibility. Battery voltage range (2.4V ~ 4V) exceeds the main part specification. Operating temperature is limited to 0°C ~ 70°C, restricting use in extended temperature applications. This substitute is suitable for new designs prioritizing power efficiency and compact packaging within the 0°C ~ 70°C temperature window.

M48T35AV-10PC1 (STMicroelectronics): This substitute maintains active product status and identical supply voltage specifications (3V ~ 3.6V) to the main part. The 28-DIP through-hole package requires different PCB layout and assembly processes compared to the surface mount original. Timekeeping current (2mA @ 3V ~ 3.6V) is lower than the main part. Operating temperature is limited to 0°C ~ 70°C. This substitute is appropriate for applications requiring through-hole mounting or legacy board designs, within the 0°C ~ 70°C operating range.

Both substitutes maintain parallel interface architecture, RoHS3 compliance, and MSL Level 1 rating. Selection between substitutes depends on package preference (surface mount versus through-hole), temperature range requirements, and power consumption constraints.

Frequently Asked Questions (FAQ)

Q: Can the BQ4802LYPWR replace the DS1501WSN+ in all applications?

A: The BQ4802LYPWR is functionally compatible for parallel interface RTC applications within its operating temperature range (0°C ~ 70°C). If your application requires operation below 0°C or above 70°C, this substitute is not suitable. The 28-TSSOP package differs from the original 28-SOIC, requiring PCB layout modifications.

Q: What is the primary advantage of the BQ4802LYPWR over the original DS1501WSN+?

A: The BQ4802LYPWR offers significantly lower timekeeping current consumption (1.5mA typical versus 4mA maximum), reducing power requirements in battery-backed applications. It is also an active product with ongoing manufacturer support, whereas the DS1501WSN+ is obsolete.

Q: Is the M48T35AV-10PC1 suitable for surface mount assembly?

A: No. The M48T35AV-10PC1 uses a 28-DIP through-hole package, requiring insertion into PCB holes and wave soldering or manual soldering. It is not compatible with surface mount assembly processes. Use the BQ4802LYPWR for surface mount applications.

Q: Do all substitutes support the same voltage ranges as the DS1501WSN+?

A: The BQ4802LYPWR extends the supply voltage range to 2.7V, providing broader low-voltage compatibility. The M48T35AV-10PC1 matches the original 3V ~ 3.6V supply range. Battery voltage specifications differ: the BQ4802LYPWR supports 2.4V ~ 4V, while the M48T35AV-10PC1 does not specify battery voltage.

Q: Are there temperature limitations with the substitute parts?

A: Both substitutes operate within 0°C ~ 70°C, which is narrower than the original DS1501WSN+ range of -40°C ~ 85°C. If your application requires extended temperature operation, neither substitute is suitable without design modification or alternative component selection.

Q: Do the substitutes maintain the same memory size as the original?

A: The DS1501WSN+ specifies 256B memory. The substitute parts do not specify memory size in the provided data. Verify memory capacity against your application requirements before selection.

Q: Are all parts RoHS3 compliant?

A: Yes. The DS1501WSN+, BQ4802LYPWR, and M48T35AV-10PC1 are all RoHS3 compliant with MSL Level 1 rating, suitable for standard manufacturing and storage conditions.