PT7C4302WEX Equivalent & Substitute Parts

Part Overview

The PT7C4302WEX is a Real Time Clock (RTC) IC Clock/Calendar manufactured by Diodes Incorporated, featuring 31 bytes of memory, 3-Wire Serial interface, and support for 12/24-hour time format with leap year capability. The device operates across a supply voltage range of 1.2V to 5.5V with battery backup from 1.5V to 5.5V, making it suitable for low-power timekeeping applications. The part is classified as obsolete, necessitating identification of functionally equivalent alternatives from active product lines to ensure design continuity and long-term component availability.

Substiute Parts

PT7C4302WEX

Diodes IncorporatedIn Stock: 5280PT7C4302WEX Datasheet

Current PartRFQ

DS1302S+T&R

Analog Devices Inc./Maxim IntegratedIn Stock: 5240DS1302S+T&R Datasheet

MFR RecommendedRFQ

DS1306E+

Analog Devices Inc./Maxim IntegratedIn Stock: 2857DS1306E+ Datasheet

MFR RecommendedRFQ

DS1306EN+

Analog Devices Inc./Maxim IntegratedIn Stock: 3213DS1306EN+ Datasheet

MFR RecommendedRFQ

DS1343E-3+

Analog Devices Inc./Maxim IntegratedIn Stock: 945DS1343E-3+ Datasheet

MFR RecommendedRFQ

DS1344D-33+

Analog Devices Inc./Maxim IntegratedIn Stock: 891DS1344D-33+ Datasheet

MFR RecommendedRFQ

DS1344E-33+T&R

Analog Devices Inc./Maxim IntegratedIn Stock: 1158DS1344E-33+T&R Datasheet

MFR RecommendedRFQ

DS1392U-33+

Analog Devices Inc./Maxim IntegratedIn Stock: 1081DS1392U-33+ 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 PT7C4302WEX is determined by the following critical parameters: interface type (3-Wire Serial), time and date format support (HH:MM:SS with 12/24-hour capability and YY-MM-DD-dd format), supply voltage compatibility, operating temperature range, and package form factor. Substitute parts must maintain functional equivalence in timekeeping capability, calendar support, and communication protocol.

The substitute parts are grouped into two categories based on interface compatibility:

Category 1: 3-Wire Serial Interface (Direct Pin-Compatible Substitutes)

• DS1302S+T&R: 8-SOIC package, 3-Wire Serial, active product status
• DS1392U-33+: 10-TFSOP/10-MSOP package, 3-Wire Serial, active product status
• RX-4571NB:B3 PURE SN: 22-LFDFN package, 3-Wire Serial, active product status

Category 2: SPI Interface (Functional Alternatives with Interface Change)

• DS1306E+: 20-TSSOP package, SPI interface, 96B memory, active product status
• DS1306EN+: 20-TSSOP package, SPI interface, 96B memory, active product status
• DS1343E-3+: 20-TSSOP package, SPI interface, 96B memory, active product status
• DS1344D-33+: 14-WFDFN package, SPI interface, 96B memory, active product status
• DS1344E-33+T&R: 20-TSSOP package, SPI interface, 96B memory, active product status

Parameter Comparison

Engineering Selection Recommendations

For Direct Pin-Compatible Substitution (3-Wire Serial Interface):

DS1302S+T&R is the primary substitute for applications requiring 3-Wire Serial interface compatibility. This part maintains the same communication protocol and time/date format support as the PT7C4302WEX. However, the operating temperature range is limited to 0°C ~ 70°C compared to the original -40°C ~ 85°C specification. This part is suitable for commercial temperature range applications. The DS1302S+T&R offers significantly lower timekeeping current consumption (0.3µA ~ 1µA) and is in active production status with established supply chain availability.

DS1392U-33+ provides 3-Wire Serial interface compatibility with extended operating temperature range (-40°C ~ 85°C) matching the original part. This device includes alarm functionality and operates across the required temperature extremes. The package form factor differs (10-TFSOP/10-MSOP versus 8-SOIC), requiring PCB layout modification. Timekeeping current consumption is higher at 175µA.

RX-4571NB:B3 PURE SN from EPSON maintains 3-Wire Serial interface and -40°C ~ 85°C operating temperature range. This part offers the lowest timekeeping current consumption (0.95µA ~ 1µA @ 3V ~ 5V) and supports the widest supply voltage range (1.6V ~ 5.5V). The 22-LFDFN package requires significant PCB redesign. REACH status is affected, requiring compliance verification for regulated applications.

For Functional Substitution (SPI Interface):

DS1306EN+ and DS1306E+ provide SPI interface with expanded memory (96B versus 31B) and alarm functionality. DS1306EN+ supports the full -40°C ~ 85°C operating temperature range, while DS1306E+ is limited to 0°C ~ 70°C. Both require firmware modification to accommodate SPI protocol instead of 3-Wire Serial. These parts are in active production with good availability.

DS1343E-3+ and DS1344D-33+ offer SPI interface with alarm and trickle charger features. DS1343E-3+ operates across -40°C ~ 85°C with 2.7V ~ 5.5V supply range. DS1344D-33+ uses a compact 14-WFDFN package with -40°C ~ 85°C operating range but requires 3V minimum supply voltage. Both require interface protocol conversion in firmware.

All substitute parts maintain ROHS3 compliance and EAR99 export classification consistent with the original PT7C4302WEX.

Frequently Asked Questions (FAQ)

Q: Can DS1302S+T&R be used as a direct replacement for PT7C4302WEX?

A: DS1302S+T&R maintains 3-Wire Serial interface compatibility and identical time/date format support, making it functionally equivalent for communication protocol. However, the operating temperature range differs: DS1302S+T&R operates 0°C ~ 70°C versus PT7C4302WEX at -40°C ~ 85°C. For applications within the commercial temperature range, this part is suitable. For extended temperature applications, DS1392U-33+ or RX-4571NB:B3 are required.

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

A: 3-Wire Serial substitutes (DS1302S+T&R, DS1392U-33+, RX-4571NB:B3) maintain the original communication protocol and require no firmware changes. SPI substitutes (DS1306EN+, DS1343E-3+, DS1344D-33+) require firmware modification to implement SPI protocol instead of 3-Wire Serial. SPI parts offer expanded memory capacity (96B versus 31B) and additional features such as alarm functionality.

Q: Does package size affect substitution compatibility?

A: Package size directly impacts PCB layout and requires design modification. DS1302S+T&R uses 8-SOIC but with different dimensions (0.209" versus 0.154" width). DS1392U-33+ uses 10-TFSOP/10-MSOP, and RX-4571NB:B3 uses 22-LFDFN, both requiring significant PCB redesign. SPI interface parts use 20-TSSOP or 14-WFDFN packages. Package selection must align with available PCB footprint space and manufacturing capabilities.

Q: Which substitute offers the lowest power consumption?

A: RX-4571NB:B3 PURE SN provides the lowest timekeeping current at 0.95µA ~ 1µA @ 3V ~ 5V, followed by DS1302S+T&R at 0.3µA ~ 1µA @ 2V ~ 5V. For battery-backed timekeeping applications, these parts extend operational life compared to the original PT7C4302WEX at 25.3µA ~ 81µA.

Q: Are all substitutes RoHS3 compliant?

A: All listed substitute parts maintain ROHS3 compliance. RX-4571NB:B3 PURE SN has affected REACH status, requiring compliance verification for applications subject to REACH regulations. All other substitutes have REACH unaffected status.

Q: What supply voltage considerations apply to substitution?

A: PT7C4302WEX operates 1.2V ~ 5.5V. DS1302S+T&R requires minimum 2V, limiting low-voltage applications. RX-4571NB:B3 supports 1.6V ~ 5.5V, providing broader low-voltage compatibility. SPI interface parts require 2V to 3V minimum depending on model. Battery backup voltage ranges vary: DS1392U-33+, DS1343E-3+, and DS1344D-33+ support 1.3V ~ 5.5V battery operation, matching extended backup capability.