Equivalent & Substitute Parts for AB0813-T3

Part Overview

The AB0813-T3 is a Real Time Clock (RTC) IC Clock/Calendar with 64B SPI interface manufactured by Abracon LLC in a 16-VFQFN Exposed Pad package. This device provides timekeeping functionality with alarm capability, leap year support, SRAM, and trickle-charger features. The product is currently obsolete, making equivalent and substitute parts necessary for new designs and ongoing production requirements. Substitute parts must maintain functional compatibility across core timekeeping parameters while accommodating package and interface variations.

Substiute Parts

AB0813-T3

Abracon LLCIn Stock: 665AB0813-T3 Datasheet

Current PartRFQ

AB0815-T3

Abracon LLCIn Stock: 127337AB0815-T3 Datasheet

DirectRFQ

DS1390U-18+

Analog Devices Inc./Maxim IntegratedIn Stock: 956DS1390U-18+ Datasheet

MFR RecommendedRFQ

MCP79511T-I/MN

Microchip TechnologyIn Stock: 963MCP79511T-I/MN Datasheet

MFR RecommendedRFQ

MCP795W21T-I/SL

Microchip TechnologyIn Stock: 1157MCP795W21T-I/SL Datasheet

MFR RecommendedRFQ

MCP795W22-I/SL

Microchip TechnologyIn Stock: 952MCP795W22-I/SL Datasheet

MFR RecommendedRFQ

MCP795W22T-I/ST

Microchip TechnologyIn Stock: 747MCP795W22T-I/ST Datasheet

MFR RecommendedRFQ

RX-4803LC:UA PURE SN

EPSONIn Stock: 1165RX-4803LC:UA PURE SN Datasheet

MFR RecommendedRFQ

RX-4803LC:UA3 PURE SN

EPSONIn Stock: 702RX-4803LC:UA3 PURE SN Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the AB0813-T3 is determined by the following critical parameters:

Functional Compatibility Parameters:

• Interface type (SPI)
• Time and date format support (HH:MM:SS:hh and YY-MM-DD-dd)
• Operating temperature range (-40°C ~ 85°C)
• Supply voltage compatibility (1.7V ~ 3.6V nominal supply)
• Battery backup voltage support (1.5V ~ 3.6V)

Physical Compatibility Parameters:

• Surface mount mounting type
• Package form factor (QFN, SOIC, TSSOP, or VSOJ variants)
• Pin count and pitch compatibility with PCB layout

Compliance Parameters:

• RoHS3 compliance
• MSL rating (1 - Unlimited)
• Product status (Active preferred for new designs; Obsolete acceptable for legacy support)

Substitute parts are grouped by package type and feature set. Direct substitutes maintain identical or superior memory capacity and timekeeping current specifications. Secondary substitutes provide functional equivalence with package or feature variations requiring design accommodation.

Parameter Comparison

Engineering Selection Recommendations

Primary Substitute: AB0815-T3

The AB0815-T3 is the direct functional upgrade from the AB0813-T3. Both devices are manufactured by Abracon LLC, share identical package geometry (16-VFQFN Exposed Pad), and maintain full voltage and temperature compatibility. The AB0815-T3 provides 256B memory versus 64B in the original part, along with additional watchdog timer functionality. The AB0815-T3 is in active production status with substantial inventory availability (127,301 pcs), making it the preferred replacement for new designs and production continuity.

Secondary Substitutes: Microchip MCP795W Series

The MCP795W21T-I/SL, MCP795W22T-I/ST, and MCP795W22-I/SL devices from Microchip Technology provide functional SPI-based RTC/Calendar operation with 64B memory and full voltage/temperature compatibility. These parts require package redesign accommodation (14-SOIC or 14-TSSOP versus 16-VFQFN) but offer active product status and enhanced feature sets including EEPROM, unique ID, and watchdog timer. Timekeeping current is specified at 1µA, which is higher than the AB0813-T3 but acceptable for most applications.

Secondary Substitute: Microchip MCP79511T-I/MN

The MCP79511T-I/MN provides 64B memory in a 10-WFDFN package with SPI interface and full voltage/temperature compatibility. This device requires significant PCB layout modification but offers active status and low timekeeping current (1µA @ 1.8V ~ 3.6V).

Alternative Substitute: EPSON RX-4803LC:UA3 PURE SN

The RX-4803LC:UA3 PURE SN from EPSON provides SPI-based RTC functionality in a compact 12-TFSOJ package. This device supports extended supply voltage range (1.6V ~ 5.5V) and maintains full temperature compatibility. However, battery backup voltage specification is not provided, and timekeeping current is higher (2.1µA ~ 3.4µA @ 3V ~ 5V). This part is suitable for applications where package size is critical and extended supply voltage range is beneficial.

Not Recommended: DS1390U-18+

The DS1390U-18+ from Analog Devices Inc./Maxim Integrated has severely restricted supply voltage range (1.71V ~ 1.89V) and significantly higher timekeeping current (100µA @ 1.71V ~ 1.89V). This device is not suitable as a general substitute for the AB0813-T3 due to incompatible power supply requirements and power consumption characteristics.

Frequently Asked Questions (FAQ)

Q: Can the AB0815-T3 be used as a direct replacement for the AB0813-T3?

A: Yes. The AB0815-T3 is a direct pin-compatible replacement in the same 16-VFQFN Exposed Pad package. Both devices share identical supply voltage ranges (1.7V ~ 3.6V), battery backup voltage (1.5V ~ 3.6V), operating temperature (-40°C ~ 85°C), and SPI interface. The AB0815-T3 provides 256B memory instead of 64B and includes a watchdog timer. No PCB modifications are required.

Q: What are the key differences between the Microchip MCP795W series substitutes?

A: The MCP795W21T-I/SL, MCP795W22T-I/ST, and MCP795W22-I/SL all provide 64B memory, SPI interface, and identical voltage/temperature specifications. The primary differences are packaging (14-SOIC versus 14-TSSOP) and tape/reel versus tube packaging. All three devices require PCB redesign to accommodate the 14-pin SOIC or TSSOP package versus the original 16-pin QFN.

Q: Why is the DS1390U-18+ not recommended as a substitute?

A: The DS1390U-18+ has a severely restricted supply voltage range of 1.71V ~ 1.89V, which is incompatible with the AB0813-T3 specification of 1.7V ~ 3.6V. Additionally, timekeeping current is 100µA, which is approximately 500 times higher than the AB0813-T3 (0.17µA ~ 0.22µA). This device is unsuitable for battery-backed applications and most general-purpose designs.

Q: Can the EPSON RX-4803LC:UA3 PURE SN be used in place of the AB0813-T3?

A: The RX-4803LC:UA3 PURE SN provides SPI-based RTC functionality with compatible operating temperature range and extended supply voltage support (1.6V ~ 5.5V). However, battery backup voltage is not specified, and timekeeping current is higher (2.1µA ~ 3.4µA). The 12-TFSOJ package requires PCB redesign. This device is suitable only for applications where extended supply voltage range is required and package size is a priority.

Q: What package considerations apply when selecting a substitute?

A: The AB0813-T3 uses a 16-VFQFN Exposed Pad package. The AB0815-T3 maintains this package, requiring no PCB modifications. Microchip alternatives use 14-SOIC, 14-TSSOP, or 10-WFDFN packages, all requiring PCB layout redesign. The EPSON RX-4803LC:UA3 uses a 12-TFSOJ package. Package selection impacts PCB area, thermal management, and manufacturing processes.

Q: Are all substitute parts RoHS3 compliant?

A: Yes. All substitute parts listed (AB0815-T3, MCP795W21T-I/SL, MCP795W22T-I/ST, MCP795W22-I/SL, MCP79511T-I/MN, and RX-4803LC:UA3 PURE SN) are RoHS3 compliant with MSL rating of 1 (Unlimited), matching the original AB0813-T3 specifications.

Q: Which substitute offers the best inventory availability?

A: The AB0815-T3 offers the highest inventory availability with 127,301 pcs in stock. The MCP795W21T-I/SL has 1,068 pcs, MCP795W22T-I/ST has 677 pcs, MCP79511T-I/MN has 853 pcs, and RX-4803LC:UA3 PURE SN has 659 pcs available.