DS1685E-5 Real Time Clock IC - Equivalent & Substitute Parts

Part Overview

The DS1685E-5 is a Real Time Clock (RTC) IC with integrated Clock/Calendar functionality, manufactured by Analog Devices Inc./Maxim Integrated. This surface mount device operates in the 24-TSSOP package and provides 242 bytes of NVSRAM with parallel interface connectivity. The DS1685E-5 is classified as obsolete, making identification of functionally equivalent alternatives essential for ongoing system support and new design implementations. Substitute parts must maintain electrical compatibility across supply voltage, timekeeping current, operating temperature, and interface specifications while accommodating different packaging formats.

Substiute Parts

DS1685E-5

Analog Devices Inc./Maxim IntegratedIn Stock: 1482DS1685E-5 Datasheet

Current PartRFQ

DS1685E-5+

Analog Devices Inc./Maxim IntegratedIn Stock: 3449DS1685E-5+ Datasheet

DirectRFQ

M48T18-150PC1

STMicroelectronicsIn Stock: 1310M48T18-150PC1 Datasheet

MFR RecommendedRFQ

M48T58Y-70PC1

STMicroelectronicsIn Stock: 1732M48T58Y-70PC1 Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the DS1685E-5 is determined by the following critical parameters:

• Electrical Compatibility: Supply voltage range (4.5V ~ 5.5V), battery backup voltage (2.5V ~ 3.7V), and timekeeping current (3mA @ 5V)
• Functional Equivalence: Clock/Calendar type with parallel interface, HH:MM:SS time format, and YY-MM-DD-dd date format
• Operating Conditions: Temperature range 0°C ~ 70°C
• Interface Protocol: Parallel data bus architecture
• Regulatory Compliance: RoHS and REACH status for new designs

Two substitute categories are identified:

Direct Pin-Compatible Substitute (Same Package): DS1685E-5+ maintains identical 24-TSSOP packaging, electrical specifications, and functional features while offering active product status and improved RoHS3 compliance.

Functional Equivalents (Different Package): M48T18-150PC1 and M48T58Y-70PC1 provide equivalent clock/calendar functionality with parallel interface but utilize 28-DIP through-hole packaging. These parts maintain core electrical parameters and operating temperature ranges but require PCB layout modifications.

Parameter Comparison

Engineering Selection Recommendations

For Direct Replacement (No PCB Modification Required)

DS1685E-5+ is the primary substitute for the obsolete DS1685E-5. Both parts share identical 24-TSSOP surface mount packaging, electrical specifications, and functional feature sets. The DS1685E-5+ offers active product status with ROHS3 compliance, providing long-term availability and regulatory alignment for new designs. This part is recommended for applications requiring minimal design changes.

For Functional Equivalence (PCB Layout Modification Required)

M48T18-150PC1 and M48T58Y-70PC1 provide equivalent clock/calendar functionality with parallel interface operation. Both parts maintain the required 4.5V ~ 5.5V supply voltage, 3mA timekeeping current, and 0°C ~ 70°C operating temperature range. These STMicroelectronics parts operate in 28-DIP through-hole packages, requiring PCB redesign for socket or through-hole mounting. Both parts carry ROHS3 compliance and active product status. M48T18-150PC1 includes watchdog timer functionality; M48T58Y-70PC1 provides leap year support. Selection between these parts depends on specific feature requirements and PCB layout constraints.

Frequently Asked Questions (FAQ)

Q: Can DS1685E-5+ be used as a direct replacement for DS1685E-5?

A: Yes. DS1685E-5+ maintains identical electrical specifications, package format (24-TSSOP), and functional features. No circuit modifications are required. The primary difference is active product status and improved RoHS3 compliance.

Q: What are the key differences between the 24-TSSOP and 28-DIP package options?

A: The DS1685E-5 and DS1685E-5+ use 24-TSSOP surface mount packaging (0.173" width, 4.40mm). M48T18-150PC1 and M48T58Y-70PC1 use 28-DIP through-hole modules (0.600" width, 15.24mm). Package selection affects PCB layout, mounting method, and board space requirements. Surface mount packages are more compact; through-hole packages support legacy board designs.

Q: Are the STMicroelectronics M48T18-150PC1 and M48T58Y-70PC1 electrically compatible with DS1685E-5?

A: Both parts maintain electrical compatibility across supply voltage (4.5V ~ 5.5V), timekeeping current (3mA), operating temperature (0°C ~ 70°C), and parallel interface operation. Time and date formats are compatible. Feature differences exist: M48T18-150PC1 includes watchdog timer; M48T58Y-70PC1 provides leap year support. Neither part supports 12-hour time format operation.

Q: What is the impact of RoHS compliance status on part selection?

A: DS1685E-5 is RoHS non-compliant; all substitute parts (DS1685E-5+, M48T18-150PC1, M48T58Y-70PC1) are ROHS3 compliant. For new designs subject to RoHS regulations, compliant substitutes are required. For legacy system maintenance, RoHS status may not be a constraint.

Q: Can M48T18-150PC1 or M48T58Y-70PC1 be used in existing DS1685E-5 surface mount designs without modification?

A: No. These parts require through-hole mounting and 28-DIP sockets. Existing surface mount PCB designs for 24-TSSOP packages cannot accommodate 28-DIP modules without significant layout redesign. DS1685E-5+ is the appropriate choice for existing surface mount designs.

Q: What memory capacity differences exist between substitute parts?

A: DS1685E-5 and DS1685E-5+ provide 242 bytes of NVSRAM. M48T18-150PC1 and M48T58Y-70PC1 memory specifications are not provided in the available data. Verify memory requirements against application specifications before selection.