DS1685QN-5+ Real Time Clock IC Equivalent & Substitute Parts

Part Overview

The DS1685QN-5+ is an Active status Real Time Clock (RTC) IC with integrated Clock/Calendar functionality, manufactured by Analog Devices Inc./Maxim Integrated. This 28-LCC (J-Lead) surface mount device provides parallel interface timekeeping with 242 bytes of NVSRAM, alarm capability, and square wave output. The component operates across industrial temperature ranges (-40°C to 85°C) with dual supply voltage support (4.5V–5.5V main, 2.5V–3.7V battery backup). Equivalent and substitute parts are identified based on matching functional parameters: parallel interface architecture, clock/calendar type classification, compatible voltage specifications, and package form factor compatibility within the RTC Clock/Timing category.

Substiute Parts

DS1685QN-5+

Analog Devices Inc./Maxim IntegratedIn Stock: 780DS1685QN-5+ Datasheet

Current PartRFQ

DS1685QN-5+

Analog Devices Inc./Maxim IntegratedIn Stock: 780DS1685QN-5+ Datasheet

DirectRFQ

M48T02-70PC1

STMicroelectronicsIn Stock: 1276M48T02-70PC1 Datasheet

MFR RecommendedRFQ

M48T12-70PC1

STMicroelectronicsIn Stock: 2150M48T12-70PC1 Datasheet

MFR RecommendedRFQ

M48T37V-10MH1F

STMicroelectronicsIn Stock: 1945M48T37V-10MH1F Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the DS1685QN-5+ is determined by the following critical parameters:

Primary Matching Criteria:

• Functional Type: Clock/Calendar RTC IC
• Interface Architecture: Parallel
• Supply Voltage Compatibility: Overlapping or equivalent voltage ranges (4.5V–5.5V primary supply)
• Package Classification: Surface mount or through-hole 24-DIP/28-pin configurations
• Operating Temperature Range: Minimum -40°C to 85°C coverage or equivalent industrial range
• Memory Architecture: NVSRAM or equivalent non-volatile storage
• Time/Date Format Support: HH:MM:SS and YY-MM-DD-dd capability

Identified Substitute Parts:

1. M48T02-70PC1 (STMicroelectronics) – Through-hole 24-DIP package, Timekeeper® series, 4.75V–5.5V supply, 0°C–70°C operating range
2. M48T12-70PC1 (STMicroelectronics) – Through-hole 24-DIP package, Timekeeper® series, 4.5V–5.5V supply, 0°C–70°C operating range
3. M48T37V-10MH1F (STMicroelectronics) – Surface mount 44-BSOP package, Timekeeper® series, 3V–3.6V supply, 0°C–70°C operating range

All substitute parts maintain Clock/Calendar functionality, parallel interface architecture, and ROHS3 compliance. Package form factors differ (24-DIP through-hole vs. 28-LCC surface mount vs. 44-BSOP surface mount), requiring PCB layout and socket compatibility verification during design integration.

Parameter Comparison

Engineering Selection Recommendations

DS1685QN-5+ Direct Equivalent: The DS1685QN-5+ itself remains the primary specification match, with Active product status, ROHS3 compliance, and MSL-1 moisture sensitivity rating supporting unlimited shelf life storage.

M48T12-70PC1 Selection Criteria: M48T12-70PC1 provides the closest electrical parameter alignment with 4.5V–5.5V supply voltage matching and 3mA timekeeping current specification. Through-hole 24-DIP package requires PCB redesign from surface mount 28-LCC footprint. Operating temperature range (0°C–70°C) is narrower than DS1685QN-5+ (-40°C–85°C), limiting use in extended industrial temperature applications. ROHS3 compliance and MSL-1 rating maintained. Timekeeper® series designation indicates STMicroelectronics manufacturing heritage.

M48T02-70PC1 Selection Criteria: M48T02-70PC1 operates within 4.75V–5.5V supply range, establishing a 0.25V minimum offset from DS1685QN-5+ specification floor (4.5V). Through-hole 24-DIP package and 0°C–70°C operating range apply equivalent constraints as M48T12-70PC1. ROHS3 compliance and MSL-1 rating maintained. Suitable for applications where minimum supply voltage floor of 4.75V is acceptable.

M48T37V-10MH1F Selection Criteria: M48T37V-10MH1F operates at reduced voltage (3V–3.6V) with lower timekeeping current (2mA), requiring complete power supply architecture redesign. Surface mount 44-BSOP package maintains SMD mounting compatibility but introduces different footprint geometry. Operating temperature range (0°C–70°C) and MSL-3 moisture sensitivity (168-hour limit) represent operational constraints. Suitable only for low-voltage system architectures with modified thermal and storage handling protocols.

All substitute parts maintain Active product status and ROHS3 compliance, supporting regulatory continuity in design transitions.

Frequently Asked Questions (FAQ)

Q: Can M48T02-70PC1 or M48T12-70PC1 directly replace DS1685QN-5+ on existing PCBs?

A: No. M48T02-70PC1 and M48T12-70PC1 use through-hole 24-DIP package format, while DS1685QN-5+ uses surface mount 28-LCC (J-Lead) package. PCB layout, socket design, and component placement require redesign. Electrical interface (parallel) and functional architecture (Clock/Calendar) are compatible, but physical integration is not pin-compatible.

Q: What is the primary voltage compatibility constraint between DS1685QN-5+ and M48T02-70PC1?

A: DS1685QN-5+ specifies 4.5V–5.5V supply range, while M48T02-70PC1 specifies 4.75V–5.5V. M48T02-70PC1 does not guarantee operation below 4.75V. Systems designed for 4.5V–4.74V operation cannot use M48T02-70PC1 as a substitute without power supply modification.

Q: Is M48T37V-10MH1F suitable for applications currently using DS1685QN-5+?

A: M48T37V-10MH1F requires 3V–3.6V supply voltage, fundamentally different from DS1685QN-5+ (4.5V–5.5V). Complete power supply redesign is necessary. Surface mount package compatibility exists, but voltage architecture incompatibility prevents direct substitution in 5V systems. Suitable only for new designs with 3V supply architecture.

Q: How do operating temperature ranges affect substitution decisions?

A: DS1685QN-5+ operates -40°C to 85°C (industrial range). M48T02-70PC1, M48T12-70PC1, and M48T37V-10MH1F operate 0°C to 70°C (commercial range). Applications requiring operation below 0°C or above 70°C cannot use these substitutes. Verify end-use temperature requirements before selection.

Q: What is the significance of MSL (Moisture Sensitivity Level) differences?

A: DS1685QN-5+, M48T02-70PC1, and M48T12-70PC1 carry MSL-1 (unlimited shelf life). M48T37V-10MH1F carries MSL-3 (168-hour limit after moisture exposure). MSL-3 components require controlled storage and handling protocols. Manufacturing and assembly processes must account for reduced moisture tolerance windows.

Q: Are all substitute parts ROHS3 compliant?

A: Yes. DS1685QN-5+, M48T02-70PC1, M48T12-70PC1, and M48T37V-10MH1F all carry ROHS3 Compliant status, supporting regulatory continuity in design transitions and supply chain compliance.

Q: What memory architecture differences exist between these parts?

A: DS1685QN-5+ specifies 242B memory with NVSRAM architecture. M48T02-70PC1, M48T12-70PC1, and M48T37V-10MH1F do not specify memory size in provided parameters. Functional Clock/Calendar capability is maintained across all parts, but application-specific memory requirements must be verified against detailed datasheets before integration.