DS12885S Real Time Clock IC Equivalent & Substitute Parts

Part Overview

The DS12885S is a Real Time Clock (RTC) IC with integrated Clock/Calendar functionality, manufactured by Analog Devices Inc./Maxim Integrated. This device provides 114 bytes of parallel interface memory with alarm, daylight savings, leap year, and non-volatile SRAM capabilities. The DS12885S is classified as obsolete, making equivalent and substitute parts necessary for new designs and ongoing system support. Substitute parts must maintain functional compatibility across clock/calendar operations, parallel interface architecture, and supply voltage specifications.

Substiute Parts

DS12885S

Analog Devices Inc./Maxim IntegratedIn Stock: 1579DS12885S Datasheet

Current PartRFQ

DS12885S+

Analog Devices Inc./Maxim IntegratedIn Stock: 2367DS12885S+ Datasheet

DirectRFQ

BQ3285S-SB2

Texas InstrumentsIn Stock: 1987BQ3285S-SB2 Datasheet

DirectRFQ

BQ4802YPW

Texas InstrumentsIn Stock: 1928BQ4802YPW Datasheet

MFR RecommendedRFQ

DP8573AVX/NOPB

National SemiconductorIn Stock: 1484DP8573AVX/NOPB Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the DS12885S are classified into two categories based on electrical and mechanical compatibility:

Category 1: Direct Functional Equivalents (Same Package) Parts that maintain identical or equivalent electrical specifications, package form factor (24-SOIC), and feature set. These substitutes are pin-compatible and require no circuit redesign.

Category 2: Functional Equivalents (Different Package) Parts that maintain core RTC clock/calendar functionality and parallel interface but utilize different package configurations. These require PCB layout modifications and may involve pinout verification.

Key Parameters Determining Substitution:

• Parallel interface architecture
• Clock/Calendar functionality with HH:MM:SS and YY-MM-DD-dd format support
• Supply voltage range: 4.5V ~ 5.5V (primary), 2.5V ~ 4V (battery backup)
• Operating temperature range: 0°C ~ 70°C
• Surface mount mounting type
• 24-SOIC or compatible package footprint

Parameter Comparison

Engineering Selection Recommendations

For Direct Pin-Compatible Replacement (No PCB Redesign):

DS12885S+ is the primary substitute for the DS12885S. Both devices share identical 24-SOIC packaging, electrical specifications, and functional feature sets. DS12885S+ is actively manufactured by Analog Devices Inc./Maxim Integrated and maintains ROHS3 compliance, addressing the obsolescence of the original DS12885S. This substitution requires no circuit modifications.

BQ3285S-SB2 (Texas Instruments) provides an alternative direct substitute with matching 24-SOIC packaging and equivalent electrical parameters. This device is actively produced and ROHS3 compliant. Current-timekeeping specifications are not provided for this part.

For Applications Permitting Package Change:

BQ4802YPW (Texas Instruments) offers reduced timekeeping current consumption (1.5mA typical) and extended operating temperature range (-40°C to 85°C) compared to the original specification. This device utilizes 28-TSSOP packaging and includes additional features (Supervisor, Watchdog Timer). PCB layout modification is required.

DP8573AVX/NOPB (National Semiconductor) provides the lowest timekeeping current (1µA @ 5V) and widest battery voltage range (2.2V ~ 5.1V). This device uses 28-LCC (J-Lead) packaging and supports extended operating temperature (-40°C to 85°C). Significant PCB redesign is necessary for this substitution.

Compliance Considerations:

The original DS12885S is RoHS non-compliant. All active substitute parts (DS12885S+, BQ3285S-SB2, BQ4802YPW) are ROHS3 compliant, supporting modern manufacturing and environmental requirements.

Frequently Asked Questions (FAQ)

Q: Can DS12885S+ be used as a direct replacement for DS12885S?

A: Yes. DS12885S+ is a direct pin-compatible substitute with identical 24-SOIC packaging, supply voltage specifications (4.5V ~ 5.5V primary, 2.5V ~ 4V battery), and clock/calendar functionality. No circuit modifications are required. DS12885S+ is actively manufactured and ROHS3 compliant.

Q: What are the key differences between BQ3285S-SB2 and DS12885S?

A: BQ3285S-SB2 maintains identical packaging (24-SOIC), supply voltage range, and clock/calendar format specifications. The primary difference is manufacturer (Texas Instruments vs. Analog Devices). Current-timekeeping specifications are not provided for BQ3285S-SB2. Both devices support parallel interface architecture and equivalent feature sets.

Q: Why would BQ4802YPW be selected over DS12885S+?

A: BQ4802YPW offers significantly reduced timekeeping current consumption (1.5mA typical vs. 15mA maximum) and extended operating temperature range (-40°C to 85°C vs. 0°C to 70°C). These advantages require PCB layout modification due to different packaging (28-TSSOP vs. 24-SOIC). Selection depends on power budget and thermal requirements.

Q: Is DP8573AVX/NOPB compatible with existing DS12885S circuit designs?

A: DP8573AVX/NOPB provides equivalent clock/calendar functionality and parallel interface but uses 28-LCC (J-Lead) packaging instead of 24-SOIC. Pinout verification and PCB redesign are required. This device offers the lowest timekeeping current (1µA @ 5V) and widest battery voltage range (2.2V ~ 5.1V), making it suitable for low-power applications with design flexibility.

Q: What packaging options are available for RTC clock/calendar substitutes?

A: Three package types are available: 24-SOIC (DS12885S, DS12885S+, BQ3285S-SB2), 28-TSSOP (BQ4802YPW), and 28-LCC J-Lead (DP8573AVX/NOPB). Direct substitution without PCB modification is limited to 24-SOIC devices. Alternative packages require footprint redesign and pinout verification.

Q: Are all substitute parts ROHS3 compliant?

A: DS12885S+ (Analog Devices), BQ3285S-SB2 (Texas Instruments), and BQ4802YPW (Texas Instruments) are ROHS3 compliant. The original DS12885S is RoHS non-compliant. DP8573AVX/NOPB RoHS status is not specified in available documentation.