DS12885T Equivalent & Substitute Parts

Part Overview

The DS12885T 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 NVSRAM with parallel interface, supporting 12/24-hour time format and YY-MM-DD-dd date format. The DS12885T is classified as obsolete, making equivalent and substitute parts necessary for new designs and ongoing system support.

Substiute Parts

DS12885T

Analog Devices Inc./Maxim IntegratedIn Stock: 939DS12885T Datasheet

Current PartRFQ

DS12885T+

Analog Devices Inc./Maxim IntegratedIn Stock: 1283DS12885T+ Datasheet

DirectRFQ

BQ4802LYDWR

Texas InstrumentsIn Stock: 3828BQ4802LYDWR Datasheet

MFR RecommendedRFQ

BQ4802LYPWR

Texas InstrumentsIn Stock: 28912BQ4802LYPWR Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution for the DS12885T is determined by the following critical parameters:

Primary Substitution Criteria:

• Real Time Clock functionality with Clock/Calendar capability
• Parallel interface architecture
• Time format support: HH:MM:SS (12/24 hr)
• Date format support: YY-MM-DD-dd
• Operating temperature range: 0°C ~ 70°C
• Surface mount technology

Substitute Categories:

Direct Equivalent (Same Manufacturer): DS12885T+ represents the active production equivalent of the obsolete DS12885T. Both devices share identical functional specifications, memory size (114B), electrical characteristics, and parallel interface. The primary difference is product status (active vs. obsolete) and packaging format (Tray vs. standard).

Cross-Manufacturer Alternatives: BQ4802LYDWR and BQ4802LYPWR (Texas Instruments) provide RTC Clock/Calendar functionality with parallel interface and matching time/date format support. These devices operate at different supply voltage ranges (2.7V ~ 3.6V) and feature enhanced functionality including supervisor and watchdog timer capabilities. Package types differ (28-SOIC and 28-TSSOP respectively) from the original 32-TQFP.

Parameter Comparison

Engineering Selection Recommendations

For Direct Replacement (Preferred): DS12885T+ is the recommended substitute for obsolete DS12885T applications. Both devices maintain identical electrical specifications, memory capacity, and functional features. DS12885T+ offers improved compliance status (ROHS3 Compliant vs. RoHS non-compliant) and superior moisture sensitivity rating (MSL 1 vs. MSL 3), providing better long-term reliability and regulatory alignment.

For Cross-Manufacturer Substitution: BQ4802LYDWR and BQ4802LYPWR provide functional RTC Clock/Calendar capability with parallel interface and matching time/date format support. Selection between these alternatives depends on package requirements: BQ4802LYDWR uses 28-SOIC packaging, while BQ4802LYPWR uses 28-TSSOP packaging. Both operate at reduced supply voltage (2.7V ~ 3.6V) compared to DS12885T (4.5V ~ 5.5V), requiring circuit redesign for voltage compatibility. Both devices include supervisor and watchdog timer features not present in the original DS12885T.

Compliance Considerations: All substitute parts (DS12885T+, BQ4802LYDWR, BQ4802LYPWR) are ROHS3 Compliant with MSL 1 rating, providing superior environmental and regulatory compliance compared to the obsolete DS12885T.

Frequently Asked Questions (FAQ)

Q: Can DS12885T+ be used as a direct drop-in replacement for DS12885T?

A: DS12885T+ shares identical electrical specifications, memory size, interface type, and package dimensions with DS12885T. Both use 32-TQFP (7x7) packaging and support the same time/date formats. The primary difference is product status (active vs. obsolete) and improved compliance ratings. Direct substitution is supported from a functional and electrical standpoint.

Q: What are the key differences between DS12885T and the Texas Instruments BQ4802 alternatives?

A: The primary differences are supply voltage range (DS12885T: 4.5V ~ 5.5V vs. BQ4802: 2.7V ~ 3.6V), package type (DS12885T: 32-TQFP vs. BQ4802LYDWR: 28-SOIC vs. BQ4802LYPWR: 28-TSSOP), and additional features (BQ4802 includes supervisor and watchdog timer). All three maintain parallel interface, matching time/date format support, and identical operating temperature range.

Q: Which substitute should be selected for new designs?

A: DS12885T+ is recommended for designs requiring direct compatibility with existing DS12885T implementations. BQ4802LYDWR or BQ4802LYPWR are suitable for new designs where supply voltage can be adjusted to 2.7V ~ 3.6V range and package constraints permit 28-pin SOIC or TSSOP formats.

Q: Are there package compatibility considerations when substituting?

A: Yes. DS12885T uses 32-TQFP (7x7) packaging. BQ4802LYDWR uses 28-SOIC (0.295", 7.50mm Width), and BQ4802LYPWR uses 28-TSSOP (0.173", 4.40mm Width). PCB layout and footprint modifications are required when selecting cross-manufacturer alternatives.

Q: What is the impact of different supply voltage ranges?

A: DS12885T operates at 4.5V ~ 5.5V, while BQ4802 alternatives operate at 2.7V ~ 3.6V. Direct substitution of BQ4802 devices in existing DS12885T circuits requires voltage regulation circuit redesign to ensure proper supply voltage delivery to the RTC device.