C8051F305R Equivalent & Substitute Parts

Part Overview

The C8051F305R is an 8-bit microcontroller from Silicon Labs' C8051F30x series, featuring a 25MHz 8051 core with 2KB Flash program memory and 256 bytes of RAM. This device integrates SMBus/I2C and UART connectivity with integrated peripherals including Power-On Reset, PWM, and Watchdog Timer functionality in an 11-QFN (3x3) surface mount package.

The C8051F305R is classified as Obsolete. Locating equivalent or substitute components is necessary for ongoing system support, maintenance, and new production requirements where legacy designs must be sustained or migrated to actively supported alternatives.

Substiute Parts

C8051F305R

Silicon LabsIn Stock: 1085C8051F305R Datasheet

Current PartRFQ

C8051F305-GM

Silicon LabsIn Stock: 4195C8051F305-GM Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution for the C8051F305R is determined by strict equivalence across the following critical parameters:

• Core Architecture: 8051-based processor
• Memory Configuration: 2KB Flash program memory, 256 bytes RAM
• Operating Frequency: 25MHz maximum clock speed
• Voltage Range: 2.7V to 3.6V supply compatibility
• Connectivity Interfaces: SMBus/I2C and UART/USART support
• Integrated Peripherals: Power-On Reset, PWM, Watchdog Timer
• I/O Count: 8 I/O pins minimum
• Package Form Factor: 11-QFN (3x3) surface mount configuration
• Temperature Range: -40°C to 85°C operating specification

The C8051F305-GM qualifies as a direct substitute based on identical electrical specifications and package compatibility. Packaging format differences (Tube vs. standard) do not affect functional equivalence.

Parameter Comparison

Engineering Selection Recommendations

The C8051F305-GM provides functional equivalence to the C8051F305R across all electrical and mechanical parameters. The primary distinction is regulatory compliance: C8051F305-GM meets ROHS3 standards, whereas C8051F305R is non-compliant. For applications requiring RoHS compliance or new production qualification, C8051F305-GM is the appropriate selection. Both parts carry Obsolete or Not For New Designs status, indicating limited long-term availability from the manufacturer.

Frequently Asked Questions (FAQ)

Q: Can C8051F305-GM replace C8051F305R in existing designs?

A: Yes. Both parts are electrically and mechanically identical across all specified parameters: 8051 core, 25MHz operation, 2KB Flash, 256 bytes RAM, 2.7V–3.6V supply range, SMBus/I2C and UART connectivity, and 11-QFN (3x3) package. Pin-for-pin compatibility is maintained.

Q: What is the difference between C8051F305R and C8051F305-GM?

A: The primary difference is RoHS compliance status. C8051F305-GM is ROHS3 compliant; C8051F305R is not. Packaging format differs (Tube vs. standard), but this does not affect functional performance or PCB integration.

Q: Are there any package compatibility concerns?

A: No. Both parts use the identical 11-QFN (3x3) surface mount package with 10-VFDFN exposed pad configuration. PCB footprints, reflow profiles, and assembly processes remain unchanged.

Q: Why is the C8051F305R marked as Obsolete?

A: Silicon Labs has discontinued active production and support for the C8051F305R. The C8051F305-GM carries a "Not For New Designs" status, indicating limited availability. For new development, evaluation of actively supported microcontroller alternatives from current product lines is recommended.

Q: What are the critical substitution parameters for this device?

A: Substitution validity depends on maintaining: 8051 core architecture, 2KB Flash memory, 256 bytes RAM, 25MHz maximum frequency, 2.7V–3.6V supply voltage, SMBus/I2C and UART interfaces, 8 I/O pins, and 11-QFN (3x3) package form factor.