DS14285S+ Real Time Clock IC Equivalent & Substitute Parts

Part Overview

The DS14285S+ is a Real Time Clock (RTC) IC with integrated Clock/Calendar functionality, manufactured by Analog Devices Inc./Maxim Integrated. This device provides parallel interface timekeeping with 114 bytes of NVSRAM, alarm capability, daylight savings support, and leap year compensation. The part is classified as obsolete, making equivalent substitute components necessary for new designs and ongoing production requirements. Substitute parts must maintain functional compatibility across time format, date format, interface type, and operating voltage specifications.

Substiute Parts

DS14285S+

Analog Devices Inc./Maxim IntegratedIn Stock: 2191DS14285S+ Datasheet

Current PartRFQ

DS1685S-5+

Analog Devices Inc./Maxim IntegratedIn Stock: 1030DS1685S-5+ Datasheet

MFR RecommendedRFQ

BQ4802LYDW

Texas InstrumentsIn Stock: 1993BQ4802LYDW Datasheet

MFR RecommendedRFQ

M48T37Y-70MH1F

STMicroelectronicsIn Stock: 2256M48T37Y-70MH1F Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the DS14285S+ is determined by the following critical parameters:

Primary Compatibility Criteria:

• Parallel interface requirement (eliminates serial-only alternatives)
• Time format support for both 12-hour and 24-hour modes
• Date format compatibility (YY-MM-DD-dd structure)
• Operating voltage range overlap with 4.5V ~ 5.5V supply
• Surface mount packaging with compatible pinout

Secondary Considerations:

• Package form factor (24-SOIC preferred for direct replacement; 28-SOIC and 44-BSOP require PCB layout modification)
• Memory capacity (114B minimum for functional equivalence)
• RoHS3 compliance and MSL rating for manufacturing compatibility

The three substitute parts listed below meet these criteria with varying degrees of direct compatibility based on package type and feature set.

Parameter Comparison

Engineering Selection Recommendations

DS1685S-5+ (Recommended Primary Substitute)

The DS1685S-5+ is the preferred direct replacement for the DS14285S+. Both devices share identical 24-SOIC packaging, matching supply voltage ranges (4.5V ~ 5.5V), and parallel interface architecture. The DS1685S-5+ is in active production status with ROHS3 compliance and MSL-1 rating, eliminating moisture sensitivity constraints. The primary functional difference is increased memory capacity (242B versus 114B), which provides enhanced functionality without compromising backward compatibility. Battery supply voltage range extends to 3.7V, offering improved low-power operation margin.

BQ4802LYDW (Alternative for Low-Voltage Applications)

The BQ4802LYDW from Texas Instruments provides parallel RTC functionality with a different supply voltage specification (2.7V ~ 3.6V). This device is suitable only for applications where the primary supply voltage does not exceed 3.6V. The 28-SOIC package requires PCB layout modification compared to the 24-SOIC footprint of the original part. The BQ4802LYDW includes supervisor and watchdog timer features not present in the DS14285S+. Active product status and ROHS3 compliance ensure manufacturing compatibility.

M48T37Y-70MH1F (Package-Dependent Alternative)

The M48T37Y-70MH1F from STMicroelectronics (Timekeeper® series) maintains voltage compatibility (4.5V ~ 5.5V) and parallel interface operation. The 44-BSOP package represents a significant form factor change requiring substantial PCB redesign. This device is suitable only for applications where package size constraints are not critical. The MSL-3 rating (168 hours) introduces moisture sensitivity requirements during manufacturing. Active product status and ROHS3 compliance are maintained.

Frequently Asked Questions (FAQ)

Q: Can the DS1685S-5+ directly replace the DS14285S+ without PCB modification?

A: Yes. Both devices use identical 24-SOIC packaging with matching pin assignments for parallel interface operation. Supply voltage ranges are identical (4.5V ~ 5.5V). No PCB layout changes are required for direct substitution.

Q: What is the primary reason the DS14285S+ is obsolete?

A: The DS14285S+ has been superseded by the DS1685S-5+, which provides enhanced memory capacity (242B versus 114B) and improved battery voltage range (2.5V ~ 3.7V) while maintaining full functional compatibility and identical packaging.

Q: Is the BQ4802LYDW suitable for 5V supply applications?

A: No. The BQ4802LYDW operates at 2.7V ~ 3.6V supply voltage and is not compatible with 5V systems. This device is restricted to low-voltage applications only.

Q: Does the M48T37Y-70MH1F require special handling during assembly?

A: Yes. The M48T37Y-70MH1F carries an MSL-3 rating (168 hours), requiring moisture control during storage and assembly. The DS14285S+ and DS1685S-5+ both carry MSL-1 ratings (unlimited), eliminating this constraint.

Q: Are all substitute parts RoHS3 compliant?

A: Yes. The DS1685S-5+, BQ4802LYDW, and M48T37Y-70MH1F are all ROHS3 compliant, matching the compliance status of the original DS14285S+.

Q: What is the key difference in time format support between the M48T37Y-70MH1F and other substitutes?

A: The M48T37Y-70MH1F supports 24-hour time format only, while the DS14285S+, DS1685S-5+, and BQ4802LYDW all support both 12-hour and 24-hour formats. Applications requiring 12-hour format operation cannot use the M48T37Y-70MH1F.

Q: Can the BQ4802LYDW be used in designs currently using the DS14285S+ without firmware changes?

A: Functional compatibility exists for parallel interface, time format, and date format specifications. However, the different supply voltage range (2.7V ~ 3.6V versus 4.5V ~ 5.5V) requires system-level power supply redesign. The addition of supervisor and watchdog timer features may require firmware adaptation depending on application requirements.