DS1501WS+ Equivalent & Substitute Parts

Part Overview

The DS1501WS+ is a Real Time Clock (RTC) IC with Clock/Calendar functionality manufactured by Analog Devices Inc./Maxim Integrated. This device integrates a 256-byte parallel interface RTC with alarm, leap year compensation, non-volatile SRAM, square wave output, watchdog timer, and Y2K compliance in a 28-SOIC surface mount package. The DS1501WS+ is classified as obsolete, making equivalent and substitute parts necessary for ongoing system support and new design implementations.

Substiute Parts

DS1501WS+

Analog Devices Inc./Maxim IntegratedIn Stock: 769DS1501WS+ Datasheet

Current PartRFQ

BQ4802LYPWR

Texas InstrumentsIn Stock: 28912BQ4802LYPWR Datasheet

MFR RecommendedRFQ

M48T08-100PC1

STMicroelectronicsIn Stock: 1683M48T08-100PC1 Datasheet

MFR RecommendedRFQ

M48T18-100PC1

STMicroelectronicsIn Stock: 1462M48T18-100PC1 Datasheet

MFR RecommendedRFQ

M48T58Y-70MH1F

STMicroelectronicsIn Stock: 2289M48T58Y-70MH1F Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the DS1501WS+ is determined by the following critical parameters:

• Interface Type: Parallel interface requirement
• Time/Date Format: 24-hour HH:MM:SS and YY-MM-DD-dd format support
• Supply Voltage Range: Operating voltage compatibility (3V ~ 3.6V primary supply)
• Package Type: Surface mount or through-hole compatibility
• Mounting Technology: Surface mount (SOIC) or through-hole (DIP) options
• Product Status: Active or obsolete classification
• Compliance: RoHS3 and REACH compliance

The substitute parts identified maintain parallel interface architecture and clock/calendar functionality. However, packaging and voltage specifications vary across substitute options, requiring careful selection based on application requirements.

Parameter Comparison

Engineering Selection Recommendations

BQ4802LYPWR (Texas Instruments): Active product status with ROHS3 compliance. Surface mount 28-TSSOP package with reduced footprint (0.173" width). Supply voltage range 2.7V ~ 3.6V encompasses the DS1501WS+ operating range. Lower timekeeping current (1.5mA typical) compared to DS1501WS+ (4mA maximum). Supports both 12/24-hour time format. MSL rating 1 (Unlimited) matches original part. Suitable for new designs requiring low-power operation and compact packaging.

M48T08-100PC1 (STMicroelectronics): Active product status with ROHS3 compliance. Through-hole 28-DIP package. Supply voltage 4.75V ~ 5.5V requires voltage level translation from 3V ~ 3.6V supply domain. Timekeeper® series designation. MSL rating 1 (Unlimited). Suitable for legacy through-hole board designs or applications with 5V supply rails.

M48T18-100PC1 (STMicroelectronics): Active product status with ROHS3 compliance. Through-hole 28-DIP package. Supply voltage 4.5V ~ 5.5V requires voltage level translation from 3V ~ 3.6V supply domain. Timekeeper® series designation. MSL rating 1 (Unlimited). Suitable for legacy through-hole board designs or applications with 5V supply rails.

M48T58Y-70MH1F (STMicroelectronics): Active product status with ROHS3 compliance. Surface mount 28-SOIC package with SNAPHAT Sockets (0.337" width). Supply voltage 4.5V ~ 5.5V requires voltage level translation from 3V ~ 3.6V supply domain. Timekeeper® series designation. MSL rating 3 (168 Hours). Suitable for surface mount applications with 5V supply rails and socket-based implementations.

Frequently Asked Questions (FAQ)

Q: Can BQ4802LYPWR directly replace DS1501WS+ in a 3V system?

A: BQ4802LYPWR operates within the 2.7V ~ 3.6V supply range, which encompasses the DS1501WS+ operating range of 3V ~ 3.6V. However, package footprint differs (28-TSSOP vs. 28-SOIC), requiring PCB layout modification. Pin-to-pin compatibility must be verified against application schematics.

Q: Why do M48T08-100PC1 and M48T18-100PC1 require higher supply voltages?

A: These STMicroelectronics Timekeeper® devices operate at 4.75V ~ 5.5V and 4.5V ~ 5.5V respectively, compared to DS1501WS+ at 3V ~ 3.6V. Applications using these substitutes must incorporate voltage regulation or level translation circuitry to interface with 3V logic domains.

Q: What is the significance of MSL rating differences?

A: DS1501WS+ and BQ4802LYPWR carry MSL rating 1 (Unlimited moisture sensitivity level), indicating no moisture absorption restrictions during storage. M48T58Y-70MH1F carries MSL rating 3 (168 Hours), requiring controlled moisture exposure during handling and soldering operations.

Q: Are all substitute parts RoHS3 compliant?

A: All identified substitute parts (BQ4802LYPWR, M48T08-100PC1, M48T18-100PC1, M48T58Y-70MH1F) carry ROHS3 compliance certification, matching the DS1501WS+ compliance status.

Q: Which substitute offers the closest electrical compatibility with DS1501WS+?

A: BQ4802LYPWR provides the closest electrical compatibility, operating within the 2.7V ~ 3.6V supply range that overlaps with DS1501WS+ specifications. Surface mount packaging and active product status support modern design requirements.

Q: Can through-hole substitutes (M48T08-100PC1, M48T18-100PC1) be used in surface mount applications?

A: Through-hole packages require plated via holes and mechanical mounting posts on PCB. Direct substitution into surface mount designs is not feasible without significant board redesign. Surface mount alternatives (BQ4802LYPWR, M48T58Y-70MH1F) are recommended for SMT applications.