DS14285Q+ Equivalent & Substitute Parts

Part Overview

The DS14285Q+ 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 system support.

Substiute Parts

DS14285Q+

Analog Devices Inc./Maxim IntegratedIn Stock: 780DS14285Q+ Datasheet

Current PartRFQ

DS1685Q-5+

Analog Devices Inc./Maxim IntegratedIn Stock: 895DS1685Q-5+ Datasheet

MFR RecommendedRFQ

BQ3285S-SB2

Texas InstrumentsIn Stock: 1987BQ3285S-SB2 Datasheet

MFR RecommendedRFQ

M48T35AV-10PC1

STMicroelectronicsIn Stock: 1390M48T35AV-10PC1 Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the DS14285Q+ is determined by the following critical parameters:

Primary Compatibility Criteria:

• Interface type (Parallel)
• Time and date format support (HH:MM:SS 12/24 hr; YY-MM-DD-dd)
• Supply voltage range compatibility (4.5V ~ 5.5V primary, 2.5V ~ 3.6V battery)
• Operating temperature range (0°C ~ 70°C)
• Core RTC functionality (Clock/Calendar with alarm capability)
• NVSRAM presence for data retention
• Square wave output capability

Secondary Compatibility Considerations:

• Package type (surface mount or through-hole variants acceptable based on board design)
• Memory size (114B minimum for feature parity)
• Mounting technology compatibility
• Product status (active preferred for long-term availability)

The three substitute parts listed meet these criteria with varying trade-offs in package form factor, memory capacity, and current consumption characteristics.

Parameter Comparison

Engineering Selection Recommendations

DS1685Q-5+ (Analog Devices Inc./Maxim Integrated)

This part maintains identical supply voltage specifications and package form factor (28-LCC J-Lead) to the DS14285Q+. The DS1685Q-5+ is active product status, ensuring long-term availability and manufacturing support. Memory capacity is increased to 242 bytes, providing additional NVSRAM storage. The part includes Y2K support and maintains alarm, square wave output, and NVSRAM functionality. Current consumption during timekeeping operation is higher at 3mA compared to the original 0.5µA specification. This substitute is optimal for designs where package compatibility and voltage specifications are primary constraints.

BQ3285S-SB2 (Texas Instruments)

This Texas Instruments RTC provides functional equivalence with identical memory size (114B), time/date format support, and feature set including alarm, daylight savings, leap year, NVSRAM, and square wave output. Supply voltage specifications match the original part (4.5V ~ 5.5V primary, 2.5V ~ 4V battery). The BQ3285S-SB2 is active product status. The primary design consideration is package form factor: this part uses 24-SOIC packaging versus the original 28-LCC J-Lead, requiring PCB layout modification. This substitute is suitable for new designs where package footprint can be accommodated.

M48T35AV-10PC1 (STMicroelectronics)

This STMicroelectronics Timekeeper® series RTC operates on a different supply voltage range (3V ~ 3.6V) compared to the original 4.5V ~ 5.5V specification, making it suitable only for designs with compatible power supply architecture. The part uses through-hole 28-DIP Module packaging, requiring different PCB mounting technology than the surface-mount original. Time format support is limited to 24-hour operation without 12-hour mode. The M48T35AV-10PC1 is active product status. This substitute is applicable for legacy through-hole designs or systems with 3V supply rails.

All three substitutes maintain ROHS3 compliance and operating temperature range compatibility with the original DS14285Q+.

Frequently Asked Questions (FAQ)

Q: Can DS1685Q-5+ directly replace DS14285Q+ in existing designs?

A: Yes, for designs using 28-LCC J-Lead surface-mount packages with 4.5V ~ 5.5V supply voltage. The DS1685Q-5+ maintains identical package geometry and voltage specifications. Pin-level compatibility must be verified against specific application schematics, as memory organization differs (242B versus 114B). The increased timekeeping current (3mA versus 0.5µA) may impact battery backup duration calculations.

Q: What are the package compatibility implications of BQ3285S-SB2?

A: The BQ3285S-SB2 uses 24-SOIC packaging instead of the original 28-LCC J-Lead format. This requires PCB layout redesign, including footprint modification and potential signal routing changes. Pin assignments differ between packages, necessitating schematic verification. The BQ3285S-SB2 is suitable for new designs where package footprint flexibility exists.

Q: Is M48T35AV-10PC1 suitable for 5V systems?

A: No. The M48T35AV-10PC1 operates on 3V ~ 3.6V supply voltage, incompatible with the original 4.5V ~ 5.5V specification. This part is applicable only for systems redesigned around 3V supply rails. Through-hole mounting technology also differs from the original surface-mount requirement.

Q: How do memory differences affect substitution?

A: DS14285Q+ and BQ3285S-SB2 both provide 114 bytes of NVSRAM, ensuring functional equivalence for applications requiring this specific memory capacity. DS1685Q-5+ provides 242 bytes, offering additional storage without reducing compatibility. Applications dependent on exact 114-byte memory organization should verify data structure compatibility with the larger memory device.

Q: Are all substitutes RoHS3 compliant?

A: Yes. DS1685Q-5+, BQ3285S-SB2, and M48T35AV-10PC1 are all ROHS3 compliant, matching the original DS14285Q+ environmental certification status.

Q: What is the impact of timekeeping current differences?

A: DS14285Q+ specifies 0.5µA maximum timekeeping current, while DS1685Q-5+ specifies 3mA and M48T35AV-10PC1 specifies 2mA. For battery-backed operation, higher current consumption reduces backup duration. System designers must recalculate battery capacity requirements when substituting with higher-current alternatives.

Q: Does BQ3285S-SB2 support 12-hour time format?

A: Yes. BQ3285S-SB2 supports HH:MM:SS format in both 12-hour and 24-hour modes, matching the original DS14285Q+ capability.