DS1685-5 Real Time Clock IC: Equivalent & Substitute Parts

Part Overview

The DS1685-5 is a Real Time Clock (RTC) IC with integrated Clock/Calendar functionality, manufactured by Analog Devices Inc./Maxim Integrated. This 24-DIP through-hole component provides 242 bytes of NVSRAM, alarm capability, square wave output, and Y2K compliance. The DS1685-5 is classified as obsolete, making equivalent substitute parts necessary for new designs and production continuity. Substitute parts must maintain electrical compatibility across supply voltage, battery backup voltage, timekeeping current, operating temperature range, and interface specifications while accommodating different packaging formats.

Substiute Parts

DS1685-5

Analog Devices Inc./Maxim IntegratedIn Stock: 1543DS1685-5 Datasheet

Current PartRFQ

DS1685-5+

Analog Devices Inc./Maxim IntegratedIn Stock: 1293DS1685-5+ Datasheet

DirectRFQ

DP8573AVX/NOPB

National SemiconductorIn Stock: 1484DP8573AVX/NOPB Datasheet

MFR RecommendedRFQ

M48T08Y-10MH1F

STMicroelectronicsIn Stock: 1165M48T08Y-10MH1F Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution for the DS1685-5 is determined by the following critical parameters:

• Electrical Compatibility: Supply voltage range (4.5V ~ 5.5V), battery backup voltage, and timekeeping current specifications must be met or exceeded
• Functional Equivalence: Clock/Calendar type with parallel interface, time and date format support (HH:MM:SS and YY-MM-DD-dd)
• Operating Conditions: Temperature range and feature set (alarm, NVSRAM, Y2K compliance)
• Package Compatibility: Physical form factor and pin configuration for circuit board integration

The substitute parts listed below satisfy these criteria within their respective packaging formats. Direct pin-for-pin compatibility is not required; circuit board redesign may be necessary to accommodate different package types (DIP, PLCC, SOP).

Parameter Comparison

Engineering Selection Recommendations

DS1685-5+ (Direct Substitute)

The DS1685-5+ is the primary substitute for the obsolete DS1685-5. Both parts are manufactured by Analog Devices Inc./Maxim Integrated and share identical electrical specifications, functional features, and 24-DIP packaging. The DS1685-5+ is active in production and ROHS3 compliant, making it the preferred choice for designs requiring no circuit board modifications. This part maintains full compatibility with existing PCB layouts and firmware implementations.

DP8573AVX/NOPB (Functional Equivalent)

The DP8573AVX/NOPB from National Semiconductor is functionally equivalent but requires circuit board redesign due to its 28-LCC surface-mount package. This part offers extended operating temperature range (-40°C ~ 85°C) and superior timekeeping current efficiency (1µA @ 5V). The DP8573AVX/NOPB is suitable for applications requiring enhanced temperature performance or lower power consumption during battery backup operation.

M48T08Y-10MH1F (Functional Equivalent)

The M48T08Y-10MH1F from STMicroelectronics (Timekeeper® series) is functionally equivalent but requires circuit board redesign due to its 28-SOP surface-mount package with SNAPHAT sockets. This part includes watchdog timer functionality and is ROHS3 compliant. The M48T08Y-10MH1F is suitable for applications requiring additional watchdog protection or where surface-mount integration is preferred.

Frequently Asked Questions (FAQ)

Q: Can DS1685-5+ be used as a direct replacement for DS1685-5?

A: Yes. The DS1685-5+ is electrically and functionally identical to the DS1685-5 and uses the same 24-DIP through-hole package. No circuit board modifications are required. The DS1685-5+ is the recommended substitute for obsolete DS1685-5 applications.

Q: What are the key differences between the DS1685-5+ and DP8573AVX/NOPB?

A: The DS1685-5+ uses 24-DIP through-hole packaging, while the DP8573AVX/NOPB uses 28-LCC surface-mount packaging. The DP8573AVX/NOPB offers extended operating temperature range (-40°C ~ 85°C versus 0°C ~ 70°C) and significantly lower timekeeping current (1µA @ 5V versus 3mA @ 5V). Circuit board redesign is required to use the DP8573AVX/NOPB.

Q: What are the key differences between the DS1685-5+ and M48T08Y-10MH1F?

A: The DS1685-5+ uses 24-DIP through-hole packaging, while the M48T08Y-10MH1F uses 28-SOP surface-mount packaging with SNAPHAT sockets. The M48T08Y-10MH1F includes watchdog timer functionality not present in the DS1685-5+. Circuit board redesign is required to use the M48T08Y-10MH1F.

Q: Are all substitute parts RoHS compliant?

A: The DS1685-5+ and M48T08Y-10MH1F are ROHS3 compliant. The original DS1685-5 is RoHS non-compliant. The DP8573AVX/NOPB RoHS status is not specified in available documentation.

Q: Can I use DP8573AVX/NOPB or M48T08Y-10MH1F without modifying my circuit board?

A: No. Both parts use surface-mount packages (28-LCC and 28-SOP respectively) compared to the DS1685-5's 24-DIP through-hole package. Circuit board redesign is required for either substitute. Use DS1685-5+ for through-hole compatibility without board modifications.

Q: Which substitute part offers the lowest power consumption during battery backup?

A: The DP8573AVX/NOPB offers the lowest timekeeping current at 1µA @ 5V, compared to 3mA @ 5V for the DS1685-5+, DS1685-5, and M48T08Y-10MH1F. This makes the DP8573AVX/NOPB suitable for applications requiring extended battery backup operation.

Q: Do all substitute parts support 12/24-hour time format?

A: The DS1685-5+, DP8573AVX/NOPB, and M48T08Y-10MH1F all support 12/24-hour time format. The M48T08Y-10MH1F supports 24-hour format only without 12-hour option.