Equivalent & Substitute Parts for CDP68HC68T1MZ

Part Overview

The CDP68HC68T1MZ is a Real Time Clock (RTC) IC with Clock/Calendar functionality, manufactured by Renesas Electronics Corporation. This 20-SOIC surface mount device provides 32 bytes of memory, SPI interface, and integrated features including alarm, leap year support, square wave output, and watchdog timer. The part is classified as obsolete, making equivalent and substitute parts necessary for new designs and ongoing production requirements. Substitute parts must maintain functional compatibility across core timing, interface, voltage, and thermal specifications.

Substiute Parts

CDP68HC68T1MZ

Renesas Electronics CorporationIn Stock: 723CDP68HC68T1MZ Datasheet

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CDP68HC68T1M2Z96

Renesas Electronics CorporationIn Stock: 730CDP68HC68T1M2Z96 Datasheet

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DS1347T+

Analog Devices Inc./Maxim IntegratedIn Stock: 1054DS1347T+ Datasheet

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MCP79521T-I/MN

Microchip TechnologyIn Stock: 773MCP79521T-I/MN Datasheet

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MCP795W10-I/SL

Microchip TechnologyIn Stock: 2091MCP795W10-I/SL Datasheet

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MCP795W20-I/SL

Microchip TechnologyIn Stock: 1641MCP795W20-I/SL Datasheet

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MCP795W22-I/SL

Microchip TechnologyIn Stock: 952MCP795W22-I/SL Datasheet

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RX-4803SA:UA3 PURE SN

EPSONIn Stock: 1034RX-4803SA:UA3 PURE SN Datasheet

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RX-4803SA:UB PURE SN

EPSONIn Stock: 910RX-4803SA:UB PURE SN Datasheet

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Key Parameters

Substitute Part Grouping Explanation

Substitution compatibility for the CDP68HC68T1MZ is determined by the following critical parameters:

Interface Compatibility: All substitute parts must support SPI interface to maintain communication protocol compatibility with existing designs.

Voltage Specifications: Supply voltage range (3V ~ 6V) and battery backup voltage (2.2V ~ 6V) define the operating envelope. Substitute parts must support overlapping or equivalent voltage ranges.

Time and Date Format: All substitutes must support HH:MM:SS (12/24 hr) time format and YY-MM-DD-dd date format to ensure calendar functionality equivalence.

Operating Temperature: The -40°C ~ 85°C operating range is maintained across all qualified substitutes.

Core Features: Alarm and Leap Year support are mandatory features present in all substitute parts. Square Wave Output and Watchdog Timer are additional features that enhance but do not restrict substitution.

Package and Mounting: While the original part uses 20-SOIC packaging, substitute parts may use alternative surface mount packages (16-SOIC, 14-SOIC, 8-WDFN, 10-WFDFN) provided PCB layout and pin configuration can be accommodated.

Compliance: All substitutes maintain ROHS3 compliance and EAR99 ECCN classification.

Parameter Comparison

Engineering Selection Recommendations

Primary Substitute - Same Manufacturer (Renesas): CDP68HC68T1M2Z96 is the closest functional equivalent, maintaining identical voltage specifications, memory size, time/date formats, and feature set. This part transitions from obsolete to active product status while preserving design compatibility. Package change from 20-SOIC to 16-SOIC requires PCB layout modification.

Microchip MCP795 Series (MCP795W10-I/SL, MCP795W20-I/SL, MCP795W22-I/SL): These parts provide active product status with enhanced memory (64B), lower timekeeping current (1µA), and improved MSL rating (1 vs. 3). Voltage supply range is narrower (1.8V ~ 3.6V) but overlaps with the original specification. All three variants use 14-SOIC packaging. MCP795W22-I/SL includes Unique ID feature in addition to standard alarm and leap year support.

Microchip MCP79521T-I/MN: Offers 64B memory and lowest timekeeping current (1µA) in a compact 10-WFDFN package. Voltage supply range (1.8V ~ 3.6V) is narrower than the original part. Includes EEPROM and SRAM features with Unique ID support.

Analog Devices/Maxim DS1347T+: Provides lowest timekeeping current (0.7µA ~ 0.8µA) and MSL rating 1. Voltage supply range (2V ~ 5.5V) overlaps with original specification. Compact 8-WDFN package requires significant PCB redesign. No battery backup voltage specified.

EPSON RX-4803SA Series (UA3 and UB variants): Support wide voltage range (1.6V ~ 5.5V) compatible with original specification. Active product status with MSL rating 1. Time format limited to 24-hour operation. Timekeeping current (2.1µA ~ 3.4µA) is higher than Microchip alternatives but lower than original part. REACH status is affected, requiring compliance verification for specific applications.

Compliance and Certification: All substitute parts maintain ROHS3 compliance and EAR99 ECCN classification consistent with the original part. MSL rating differences (3 vs. 1) affect moisture sensitivity handling during assembly; parts with MSL 1 require less stringent moisture control.

Frequently Asked Questions (FAQ)

Q: Can I directly replace CDP68HC68T1MZ with CDP68HC68T1M2Z96 without design changes? A: Both parts share identical electrical specifications and feature sets. However, package change from 20-SOIC to 16-SOIC requires PCB layout modification. Pin configuration must be verified against datasheets before implementation.

Q: What is the primary advantage of Microchip MCP795 series substitutes? A: The MCP795 series offers active product status, lower timekeeping current consumption (1µA vs. 20µA ~ 500µA), and improved MSL rating (1 vs. 3). These parts provide better long-term availability and reduced power requirements. Trade-off is narrower voltage supply range (1.8V ~ 3.6V vs. 3V ~ 6V).

Q: Are EPSON RX-4803SA parts suitable for 12-hour time format applications? A: No. RX-4803SA variants support only 24-hour time format. Applications requiring 12-hour format must use Renesas CDP68HC68 series, Microchip MCP795 series, or Analog Devices DS1347T+.

Q: How does memory size affect substitution compatibility? A: The original CDP68HC68T1MZ provides 32B memory. Microchip MCP795 and MCP79521 series offer 64B memory, providing additional storage capacity. This is a functional enhancement, not a limitation. Applications designed for 32B operation remain compatible with 64B parts.

Q: What packaging considerations apply when selecting a substitute? A: Original 20-SOIC packaging differs from substitute options (16-SOIC, 14-SOIC, 8-WDFN, 10-WFDFN). Smaller packages reduce PCB footprint but require layout redesign. Pin count and pitch variations must be accommodated in schematic and PCB design.

Q: Which substitute offers the lowest power consumption? A: Analog Devices DS1347T+ provides the lowest timekeeping current at 0.7µA ~ 0.8µA. Microchip MCP795 series and MCP79521T-I/MN follow at 1µA. Original part consumes 20µA ~ 500µA, making modern substitutes significantly more efficient.

Q: Are there voltage compatibility issues between the original part and substitutes? A: Original part operates at 3V ~ 6V. Microchip MCP795 series operates at 1.8V ~ 3.6V, requiring system voltage verification. EPSON RX-4803SA (1.6V ~ 5.5V) and Analog Devices DS1347T+ (2V ~ 5.5V) provide broader compatibility. Verify system supply voltage before selection.

Q: What is the impact of MSL rating differences? A: Original part has MSL 3 (168 hours); substitutes have MSL 1 (unlimited). MSL 1 parts require less stringent moisture control during storage and assembly, reducing handling complexity and cost. This is an improvement over the original specification.

Q: Can I use RX-4803SA parts in applications requiring battery backup? A: No. RX-4803SA variants do not specify battery backup voltage. Original CDP68HC68T1MZ and Microchip MCP795 series support battery backup (2.2V ~ 6V and 1.3V ~ 3.6V respectively). Applications requiring battery-backed operation must use parts with specified battery voltage ranges.