DS1286I+ Equivalent & Substitute Parts

Part Overview

The DS1286I+ is a Real Time Clock (RTC) IC with integrated Clock/Calendar functionality, manufactured by Analog Devices Inc./Maxim Integrated. This 28-DIP through-hole component provides 50 bytes of SRAM, alarm capability, leap year support, square wave output, and watchdog timer functionality. The part operates across a 4.5V to 5.5V supply range with battery backup support from 2.4V to 4.6V.

The DS1286I+ is classified as obsolete. Identifying equivalent and substitute parts is necessary to support legacy system maintenance, design updates, and procurement continuity where original components are no longer readily available or cost-effective.

Substiute Parts

DS1286I+

Analog Devices Inc./Maxim IntegratedIn Stock: 6032DS1286I+ Datasheet

Current PartRFQ

BQ4802LYDWR

Texas InstrumentsIn Stock: 3828BQ4802LYDWR Datasheet

MFR RecommendedRFQ

BQ4802LYPWR

Texas InstrumentsIn Stock: 28912BQ4802LYPWR Datasheet

MFR RecommendedRFQ

M48T12-150PC1

STMicroelectronicsIn Stock: 2537M48T12-150PC1 Datasheet

MFR RecommendedRFQ

M48T35-70PC1

STMicroelectronicsIn Stock: 7799M48T35-70PC1 Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the DS1286I+ is determined by the following critical parameters:

Primary Substitution Criteria:

• Parallel interface for direct pin compatibility
• Clock/Calendar functionality with time and date format support
• Alarm and watchdog timer features
• RoHS3 compliance and REACH unaffected status
• Package compatibility or functional equivalence

Substitution Groups:

Group 1: Surface Mount Alternatives (BQ4802 Series) The BQ4802LYDWR and BQ4802LYPWR are active Texas Instruments RTC Clock/Calendar ICs with parallel interface. Both feature alarm, daylight savings, leap year, supervisor, and watchdog timer functionality. These parts operate at 2.7V to 3.6V supply with 2.4V to 4V battery backup. The primary trade-off is package format: BQ4802LYDWR uses 28-SOIC (0.295", 7.50mm) and BQ4802LYPWR uses 28-TSSOP (0.173", 4.40mm), both surface mount versus the through-hole DIP of the original part. Current consumption is significantly lower at 1.5mA typical.

Group 2: Through-Hole DIP Alternatives (STMicroelectronics Timekeeper® Series) The M48T12-150PC1 and M48T35-70PC1 are active STMicroelectronics RTC ICs in the Timekeeper® series, both offering through-hole DIP packaging compatible with legacy board designs. M48T12-150PC1 is a 24-DIP module with 4.5V to 5.5V supply operation and 3mA timekeeping current. M48T35-70PC1 is a 28-DIP module with 4.75V to 5.5V supply operation and 2mA timekeeping current. Both support 24-hour time format, leap year functionality, and parallel interface. These parts maintain through-hole mounting compatibility with the original DS1286I+.

Parameter Comparison

Engineering Selection Recommendations

For Through-Hole Board Designs: M48T35-70PC1 is the preferred substitute when board layout requires through-hole mounting. This 28-DIP STMicroelectronics part maintains mechanical compatibility with the original DS1286I+ footprint, operates within the same 4.75V to 5.5V supply range, and is currently in active production status. The part provides lower timekeeping current (2mA) compared to the original specification (7mA), reducing power consumption in battery-backed applications.

M48T12-150PC1 is an alternative through-hole option with 24-DIP packaging. This part requires board redesign to accommodate the different pin count and physical dimensions but offers active product status and ROHS3 compliance.

For Surface Mount Redesigns: BQ4802LYPWR offers the most compact surface mount solution in 28-TSSOP packaging with the highest inventory availability (28,900 pieces). This Texas Instruments part provides superior power efficiency at 1.5mA typical timekeeping current and extended battery voltage support (2.4V to 4V). The lower operating voltage range (2.7V to 3.6V) requires power supply circuit modification from the original 5V design.

BQ4802LYDWR provides an intermediate surface mount option in 28-SOIC packaging with equivalent electrical specifications to BQ4802LYPWR but larger package dimensions.

Compliance Considerations: All substitute parts maintain ROHS3 compliance and REACH unaffected status, matching the original part's regulatory standing. All parts carry EAR99 ECCN classification and 8542.39.0001 HTSUS code.

Temperature Range Limitation: The DS1286I+ operates across -40°C to 85°C. All substitute parts are rated only to 0°C to 70°C. Applications requiring the extended low-temperature specification of the original part cannot use these substitutes without design modification or alternative sourcing.

Frequently Asked Questions (FAQ)

Q: Can BQ4802LYDWR or BQ4802LYPWR be used as direct replacements in existing DS1286I+ board designs?

A: No. The BQ4802 series uses surface mount packaging (SOIC or TSSOP) versus the through-hole 28-DIP of the DS1286I+. Direct socket replacement is not possible. These parts require PCB redesign and rework. However, they provide functional equivalence through parallel interface, clock/calendar operation, alarm, and watchdog timer features.

Q: What is the primary advantage of M48T35-70PC1 over the original DS1286I+?

A: M48T35-70PC1 maintains through-hole 28-DIP packaging compatibility, enabling socket-level replacement without PCB modification. The part is in active production status, ensuring long-term availability. Timekeeping current is reduced to 2mA from the original 7mA, improving battery backup runtime. The part is ROHS3 compliant and carries equivalent regulatory certifications.

Q: Why do the BQ4802 parts operate at lower supply voltages than the DS1286I+?

A: The BQ4802LYDWR and BQ4802LYPWR are specified for 2.7V to 3.6V operation, reflecting modern low-power design practices. The original DS1286I+ operates at 4.5V to 5.5V. Applications using the BQ4802 series require power supply circuit redesign to step down from 5V logic levels to the 3.3V or lower range required by these parts.

Q: Are there temperature range limitations when substituting the DS1286I+?

A: Yes. The DS1286I+ is rated for -40°C to 85°C operation. All substitute parts (BQ4802LYDWR, BQ4802LYPWR, M48T12-150PC1, M48T35-70PC1) are rated only to 0°C to 70°C. Applications requiring extended low-temperature operation below 0°C cannot use these substitutes.

Q: What is the difference between M48T12-150PC1 and M48T35-70PC1?

A: M48T12-150PC1 is a 24-DIP package with 3mA timekeeping current at 4.5V to 5.5V supply. M48T35-70PC1 is a 28-DIP package with 2mA timekeeping current at 4.75V to 5.5V supply. The 28-DIP M48T35-70PC1 provides closer mechanical compatibility with the original DS1286I+ 28-DIP footprint and lower power consumption.

Q: Do all substitute parts support the same time and date formats as the DS1286I+?

A: The BQ4802 series supports HH:MM:SS (12/24 hr) time format and YY-MM-DD-dd date format, matching the DS1286I+ capability. The M48T12 and M48T35 series support HH:MM:SS (24 hr) time format only, without 12-hour mode. Applications requiring 12-hour time format operation must use the BQ4802 series or maintain the original DS1286I+.

Q: Which substitute part has the best inventory availability?

A: BQ4802LYPWR has the highest inventory at 28,900 pieces in stock. M48T35-70PC1 has 7,722 pieces available. BQ4802LYDWR has 3,770 pieces. M48T12-150PC1 has 2,456 pieces.