DS1501W+ Real Time Clock IC Equivalent & Substitute Parts

Part Overview

The DS1501W+ is a Real Time Clock (RTC) IC with integrated Clock/Calendar functionality, manufactured by Analog Devices Inc./Maxim Integrated. This 28-DIP parallel interface device provides 256 bytes of NVSRAM with comprehensive timekeeping features including alarm, leap year compensation, square wave output, and watchdog timer capabilities. The device operates at 3V to 3.6V supply voltage with battery backup support from 2.5V to 3.7V.

The DS1501W+ is classified as obsolete. Locating equivalent or substitute components is necessary for new designs, production continuity, or system upgrades where active product alternatives are preferred.

Substiute Parts

DS1501W+

Analog Devices Inc./Maxim IntegratedIn Stock: 1172DS1501W+ Datasheet

Current PartRFQ

DS1501W+

Analog Devices Inc./Maxim IntegratedIn Stock: 1172DS1501W+ Datasheet

DirectRFQ

BQ4802YPW

Texas InstrumentsIn Stock: 1928BQ4802YPW Datasheet

MFR RecommendedRFQ

DP8573AV/NOPB

Texas InstrumentsIn Stock: 4247DP8573AV/NOPB Datasheet

MFR RecommendedRFQ

M48T08-100PC1

STMicroelectronicsIn Stock: 1683M48T08-100PC1 Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the DS1501W+ is determined by the following critical parameters:

Primary Compatibility Criteria:

• Parallel interface architecture
• Real Time Clock with Clock/Calendar functionality
• 24-hour time format support
• YY-MM-DD-dd date format support
• Operating temperature range: 0°C ~ 70°C minimum
• RoHS3 compliance

Secondary Compatibility Considerations:

• Package type (Through Hole vs. Surface Mount affects PCB integration)
• Supply voltage range (3V ~ 3.6V vs. 4.5V ~ 5.5V requires circuit design evaluation)
• Battery backup voltage specifications
• Timekeeping current consumption
• Feature set alignment (Alarm, Leap Year, Watchdog Timer)

The three identified substitute parts meet the core functional and compliance requirements but differ in packaging, voltage specifications, and feature implementations. Each substitute maintains parallel interface architecture and calendar/clock functionality essential for direct functional replacement.

Parameter Comparison

Engineering Selection Recommendations

M48T08-100PC1 (STMicroelectronics)

This substitute maintains identical package geometry (28-DIP Through Hole) and operating temperature range as the DS1501W+. The M48T08-100PC1 is an active product with ROHS3 compliance and MSL 1 rating. Primary design consideration: supply voltage operates at 4.75V ~ 5.5V, requiring circuit voltage adjustment from the original 3V ~ 3.6V specification. This part is suitable for designs where PCB layout compatibility and through-hole mounting are required and voltage regulation can be accommodated.

BQ4802YPW (Texas Instruments)

This substitute provides active product status with ROHS3 compliance and enhanced feature set including Daylight Savings and Supervisor functions. The BQ4802YPW operates at 4.5V ~ 5.5V supply voltage and delivers lower timekeeping current (1.5mA typical) compared to the DS1501W+. Primary design consideration: surface mount package (28-TSSOP) requires PCB redesign for component placement and soldering. This part is suitable for new designs prioritizing reduced power consumption and surface mount assembly.

DP8573AV/NOPB (Texas Instruments)

This substitute is an active product with ROHS3 compliance and extended operating temperature range (-40°C ~ 85°C). The DP8573AV/NOPB delivers the lowest timekeeping current (1µA @ 5V) among all substitutes. Primary design considerations: surface mount package (28-LCC J-Lead) requires PCB redesign, supply voltage operates at 4.5V ~ 5.5V, and MSL rating is 2A (4 Weeks) requiring controlled storage conditions. This part is suitable for applications requiring extended temperature operation and minimal power consumption in new surface mount designs.

Frequently Asked Questions (FAQ)

Q: Can the M48T08-100PC1 be used as a direct replacement for the DS1501W+ without circuit modifications?

A: The M48T08-100PC1 maintains identical DIP package geometry and through-hole mounting, enabling direct PCB socket compatibility. However, the supply voltage specification differs (4.75V ~ 5.5V vs. 3V ~ 3.6V). Circuit voltage regulation must be evaluated and adjusted accordingly. Functional compatibility is confirmed through parallel interface architecture and matching date/time format specifications.

Q: What are the key differences between through-hole and surface mount substitute options?

A: The M48T08-100PC1 uses 28-DIP through-hole packaging, compatible with existing DIP sockets and breadboard layouts. The BQ4802YPW (28-TSSOP) and DP8573AV/NOPB (28-LCC) use surface mount packages requiring PCB redesign, reflow soldering, and updated assembly processes. Through-hole mounting is preferred for prototype and legacy system retrofits; surface mount is preferred for new production designs prioritizing board density and automated assembly.

Q: How do supply voltage differences affect substitution decisions?

A: The DS1501W+ operates at 3V ~ 3.6V, while all three substitutes require 4.5V ~ 5.5V or 4.75V ~ 5.5V supply voltage. Existing circuits designed for 3V operation require voltage regulation or power supply redesign to accommodate substitute parts. Battery backup voltage specifications also differ across substitutes and must be evaluated for backup power system compatibility.

Q: Which substitute offers the best power efficiency for timekeeping operation?

A: The DP8573AV/NOPB delivers the lowest timekeeping current at 1µA @ 5V, compared to 1.5mA (BQ4802YPW) and 3mA (M48T08-100PC1). The DS1501W+ operates at 4mA @ 3V ~ 3.6V. Power consumption reduction depends on supply voltage and operating conditions; direct comparison requires circuit-specific analysis.

Q: Are all substitutes RoHS3 compliant?

A: Yes. All three substitute parts (M48T08-100PC1, BQ4802YPW, DP8573AV/NOPB) maintain ROHS3 compliance matching the DS1501W+ specification. All parts are also REACH Unaffected and classified under ECCN EAR99 and HTSUS 8542.39.0001.

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

A: The DS1501W+ and M48T08-100PC1 carry MSL 1 (Unlimited) rating, allowing indefinite shelf storage without moisture control. The BQ4802YPW also carries MSL 1. The DP8573AV/NOPB carries MSL 2A (4 Weeks), requiring controlled storage conditions and bake-out procedures if storage exceeds 4 weeks. MSL 2A parts require careful inventory management and handling protocols.

Q: Can substitutes be used interchangeably in existing designs?

A: Functional interchangeability depends on specific design requirements. All substitutes maintain parallel interface and calendar/clock functionality. However, differences in package type, supply voltage, operating temperature range, and feature sets require individual evaluation. Through-hole designs (DS1501W+ and M48T08-100PC1) are more directly compatible; surface mount substitutes require PCB redesign.