DS1306E/T&R Equivalent & Substitute Parts

Part Overview

The DS1306E/T&R is a Real Time Clock (RTC) IC with integrated Clock/Calendar functionality, 96 bytes of NVSRAM, and SPI interface, manufactured by Analog Devices Inc./Maxim Integrated. This component is classified as obsolete, which necessitates identification of equivalent and substitute parts for new designs or production continuity. The DS1306E/T&R operates across a 2V to 5.5V supply range with timekeeping current consumption between 25.3µA and 81µA, housed in a 20-TSSOP surface mount package.

Substiute Parts

DS1306E/T&R

Analog Devices Inc./Maxim IntegratedIn Stock: 799DS1306E/T&R Datasheet

Current PartRFQ

DS1306E+T&R

Analog Devices Inc./Maxim IntegratedIn Stock: 3744DS1306E+T&R Datasheet

DirectRFQ

PT7C4302WEX

Diodes IncorporatedIn Stock: 5280PT7C4302WEX Datasheet

MFR RecommendedRFQ

RX-4571LC:B3 PURE SN

EPSONIn Stock: 2650RX-4571LC:B3 PURE SN Datasheet

MFR RecommendedRFQ

RX-4571NB:B3 PURE SN

EPSONIn Stock: 891RX-4571NB:B3 PURE SN Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the DS1306E/T&R is determined by the following critical parameters:

• Interface Type: SPI or 3-Wire Serial compatibility
• Memory Capacity: Minimum 31B NVSRAM (DS1306E/T&R provides 96B)
• Time/Date Format Support: HH:MM:SS and YY-MM-DD-dd capability
• Supply Voltage Range: Overlap with 2V ~ 5.5V operating window
• Operating Temperature Range: Coverage of -40°C ~ 85°C or subset thereof
• Package Type: Surface mount configurations
• RoHS Compliance: Relevant for new designs requiring regulatory compliance

The substitute parts identified fall into two categories: direct equivalents maintaining SPI interface compatibility, and functional alternatives with 3-Wire Serial interface that provide equivalent timekeeping and calendar functionality.

Parameter Comparison

Engineering Selection Recommendations

DS1306E+T&R (Direct Equivalent - Recommended for SPI Interface Requirements)

The DS1306E+T&R is the active production equivalent of the DS1306E/T&R. It maintains identical electrical specifications, memory capacity (96B), SPI interface, and 20-TSSOP package footprint. The primary difference is product status (Active vs. Obsolete) and RoHS compliance (ROHS3 Compliant). Operating temperature range is reduced to 0°C ~ 70°C, which may require evaluation for applications requiring the full -40°C ~ 85°C range. This part is suitable for direct replacement in new designs requiring SPI interface compatibility.

PT7C4302WEX (Functional Alternative - Interface Change Required)

The PT7C4302WEX provides Clock/Calendar functionality with 31B NVSRAM and 3-Wire Serial interface. It operates across 1.2V ~ 5.5V supply range and -40°C ~ 85°C temperature range, matching the original part's extended temperature capability. The 8-SOIC package requires PCB layout modification. Memory capacity is reduced to 31B. Interface conversion from SPI to 3-Wire Serial requires firmware modification. Product status is Obsolete.

RX-4571LC:B3 PURE SN (Functional Alternative - Low Power, Interface Change Required)

The RX-4571LC:B3 PURE SN is an active EPSON RTC with 3-Wire Serial interface and significantly reduced timekeeping current (0.95µA ~ 1µA @ 3V ~ 5V). It supports -40°C ~ 85°C operating temperature and includes Alarm and Leap Year features. The 12-TFSOJ package is smaller than the original 20-TSSOP. Memory size is not specified. Interface conversion from SPI to 3-Wire Serial requires firmware modification. RoHS3 compliant.

RX-4571NB:B3 PURE SN (Functional Alternative - Low Power, Interface Change Required)

The RX-4571NB:B3 PURE SN is an active EPSON RTC with 3-Wire Serial interface and ultra-low timekeeping current (0.95µA ~ 1µA @ 3V ~ 5V). It supports -40°C ~ 85°C operating temperature and includes Alarm and Leap Year features. The 22-LFDFN package requires PCB layout modification. Memory size is not specified. Interface conversion from SPI to 3-Wire Serial requires firmware modification. RoHS3 compliant.

Frequently Asked Questions (FAQ)

Q: Can DS1306E+T&R be used as a direct replacement for DS1306E/T&R?

A: Yes. The DS1306E+T&R maintains identical SPI interface, 96B memory capacity, 20-TSSOP package, and electrical specifications. The operating temperature range is reduced from -40°C ~ 85°C to 0°C ~ 70°C. Verify application temperature requirements before substitution.

Q: What is the primary difference between SPI and 3-Wire Serial interface options?

A: SPI (Serial Peripheral Interface) and 3-Wire Serial are distinct communication protocols requiring different PCB routing and firmware implementation. Direct substitution between these interface types requires protocol conversion and software modification. DS1306E+T&R maintains SPI compatibility; PT7C4302WEX, RX-4571LC:B3, and RX-4571NB:B3 use 3-Wire Serial.

Q: Does memory capacity affect substitution suitability?

A: Yes. The DS1306E/T&R provides 96B NVSRAM. PT7C4302WEX provides 31B. RX-4571LC:B3 and RX-4571NB:B3 do not specify memory capacity. Applications requiring the full 96B capacity should use DS1306E+T&R. Applications requiring less than 31B can use PT7C4302WEX.

Q: Are all substitute parts RoHS compliant?

A: DS1306E/T&R is RoHS non-compliant. DS1306E+T&R, PT7C4302WEX, RX-4571LC:B3, and RX-4571NB:B3 are all ROHS3 Compliant. New designs should prioritize RoHS-compliant alternatives.

Q: Which substitute offers the lowest power consumption?

A: RX-4571LC:B3 PURE SN and RX-4571NB:B3 PURE SN both provide 0.95µA ~ 1µA timekeeping current at 3V ~ 5V, significantly lower than the original part's 25.3µA ~ 81µA. These parts require 3-Wire Serial interface implementation.

Q: What package considerations apply to substitution?

A: DS1306E+T&R uses the same 20-TSSOP package as the original part. PT7C4302WEX uses 8-SOIC, RX-4571LC:B3 uses 12-TFSOJ, and RX-4571NB:B3 uses 22-LFDFN. Package changes require PCB layout modification and footprint verification.

Q: Can the operating temperature range be reduced from -40°C ~ 85°C to 0°C ~ 70°C?

A: DS1306E+T&R operates at 0°C ~ 70°C, narrower than the original -40°C ~ 85°C range. Substitution is acceptable only if the application operates within 0°C ~ 70°C. Applications requiring extended temperature range should use PT7C4302WEX, RX-4571LC:B3, or RX-4571NB:B3, all rated to -40°C ~ 85°C.