PCF2123TS/1,112 Equivalent & Substitute Parts

Part Overview

The PCF2123TS/1,112 is a Real Time Clock (RTC) IC with integrated clock/calendar functionality, manufactured by NXP USA Inc. This Surface Mount device operates via SPI interface and is designed for applications requiring accurate timekeeping with alarm capability, leap year compensation, and watchdog timer functionality. The part is currently Active in product status with 910 units in stock. Substitute parts are identified when equivalent functional requirements must be met due to component availability, design optimization, or supply chain considerations.

Substiute Parts

PCF2123TS/1,112

NXP USA Inc.In Stock: 993PCF2123TS/1,112 Datasheet

Current PartRFQ

MCP79521T-I/MS

Microchip TechnologyIn Stock: 3558MCP79521T-I/MS Datasheet

MFR RecommendedRFQ

MCP795W11-I/SL

Microchip TechnologyIn Stock: 1214MCP795W11-I/SL Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the PCF2123TS/1,112 are qualified based on the following criteria:

Core Functional Requirements:

• Clock/Calendar functionality with SPI interface
• Operating temperature range: -40°C ~ 85°C
• Surface Mount technology
• Active product status
• ROHS3 compliance and MSL Level 1

Electrical Compatibility Criteria:

• Supply voltage overlap within system operating range
• Timekeeping current consumption suitable for low-power applications
• Compatible time and date format support (HH:MM:SS and YY-MM-DD-dd)

Mechanical Compatibility:

• Surface Mount package types (TSSOP, SOIC, MSOP acceptable)
• Pin count and footprint considerations for PCB layout

The identified substitutes (MCP79521T-I/MS and MCP795W11-I/SL) meet these core criteria while offering additional features such as EEPROM and SRAM memory, which do not preclude their use as functional equivalents.

Parameter Comparison

Engineering Selection Recommendations

PCF2123TS/1,112 (Primary Part): All three parts maintain Active product status with ROHS3 compliance and MSL Level 1 rating. The PCF2123TS/1,112 offers the widest supply voltage range (1.6V ~ 5.5V) and lowest timekeeping current consumption (0.33µA ~ 0.38µA), making it optimal for battery-backed or ultra-low-power applications. The 14-TSSOP package provides a standard footprint for this device class.

MCP795W11-I/SL (Preferred Substitute): This part maintains the 14-pin package format (14-SOIC) and includes watchdog timer functionality matching the primary part. Supply voltage is constrained to 1.8V ~ 3.6V. Additional features include EEPROM and SRAM memory. Suitable for applications where the narrower voltage range is acceptable and additional memory is beneficial.

MCP79521T-I/MS (Alternative Substitute): This part operates within 1.8V ~ 3.6V supply range in a 10-MSOP package. Pin count reduction (10 pins vs. 14 pins) requires PCB layout modification. Includes EEPROM and SRAM memory. Suitable for space-constrained designs where package size reduction is prioritized.

Frequently Asked Questions (FAQ)

Q: Can MCP795W11-I/SL directly replace PCF2123TS/1,112 without firmware changes?

A: Both parts support SPI interface, identical time/date formats (HH:MM:SS and YY-MM-DD-dd), and operate across the overlapping temperature range (-40°C ~ 85°C). However, the supply voltage range differs (PCF2123TS/1,112: 1.6V ~ 5.5V vs. MCP795W11-I/SL: 1.8V ~ 3.6V). Verify your system supply voltage falls within 1.8V ~ 3.6V before substitution. Register mapping and command protocols must be evaluated against your firmware implementation.

Q: What are the package differences between these parts?

A: PCF2123TS/1,112 uses 14-TSSOP (0.173", 4.40mm width). MCP795W11-I/SL uses 14-SOIC (0.154", 3.90mm width). MCP79521T-I/MS uses 10-MSOP (0.118", 3.00mm width). TSSOP and SOIC packages are mechanically similar but have different footprints. MSOP is significantly smaller and requires PCB redesign.

Q: Are all three parts suitable for battery-backed operation?

A: PCF2123TS/1,112 specifies timekeeping current of 0.33µA ~ 0.38µA @ 2V ~ 5V. MCP795W11-I/SL and MCP79521T-I/MS specify 1µA @ 1.8V ~ 3.6V. The primary part offers lower current consumption. For battery-backed applications, calculate battery life based on the specific timekeeping current of your selected part.

Q: Do the substitute parts support all features of the PCF2123TS/1,112?

A: Both substitutes support Alarm, Leap Year, and Square Wave Output. MCP795W11-I/SL includes Watchdog Timer matching the primary part. Both substitutes add EEPROM, SRAM, and Unique ID features not present in the primary part. These additional features do not prevent substitution but require firmware awareness.

Q: What compliance certifications apply to all three parts?

A: All three parts are ROHS3 Compliant, REACH Unaffected, and carry MSL Level 1 (Unlimited) rating. ECCN classification is EAR99 for all parts. HTSUS code is 8542.39.0001 for all parts.