C8051F851-C-GU

Overview

The C8051F851-C-GU is a discontinued 8-bit microcontroller from Silicon Labs, part of the C8051F85x/86x family. It features a high-speed CIP-51 core operating at up to 25 MHz with standard 8051 instruction set compatibility. The device integrates 8 kB of in-system programmable Flash memory and 512 Bytes of RAM. Key peripherals include a 12-bit ADC with up to 16 channels, two analog comparators, four 16-bit timers, a Programmable Counter Array (PCA), and communication interfaces such as UART, SPI, and I2C/SMBus. It operates on a supply voltage of 2.2 V to 3.6 V and is housed in a 24-pin QSOP package.

Feature Summary

• High-performance CIP-51 core delivering up to 25 MIPS throughput with pipelined architecture.
• Integrated mixed-signal capabilities including a 12-bit ADC with multiple input channels and dual analog comparators.
• Comprehensive digital peripheral set featuring UART, SPI, I2C/SMBus, and multiple timer/PWM modules.
• On-chip debug circuitry enabling full-speed, non-intrusive in-system debugging without external emulators.

Applications

• Battery chargers
• Electronic toys and games
• Motor control systems
• Optical communications

Procurement Notes

This component is officially designated as Not Recommended for New Designs (NRND) and has reached End of Life (EOL). Verify current availability through authorized distributors, noting that stock may be limited or obsolete. Confirm the specific revision level and manufacturing date code against project requirements before procurement, as replacement components may require design adjustments.

Selection Notes

Select this MCU for applications requiring a cost-effective 8-bit solution with integrated analog peripherals and robust debug support. Ensure the design accommodates the 2.2 V to 3.6 V supply range and the 24-pin QSOP footprint. Consider the NRND status when planning long-term production lifecycles, as future supply may be constrained compared to active series members.

Part Context

The C8051F851-C-GU belongs to the C8051F85x/86x low-cost 8-bit MCU family from Silicon Labs. This series combines a fast 8051-compatible core with significant on-chip resources, targeting embedded systems that need mixed-signal processing. The -G suffix indicates commercial temperature grade (-40°C to +85°C), while -GU specifies the 24-pin QSOP package option within this product line.

Replacement Considerations

Public confirmed substitute part numbers: EFM8BB51F8G-C-TSSOP20R.

FAQ

What is the maximum system clock frequency for the C8051F851-C-GU?

The maximum system clock frequency is 25 MHz, allowing for up to 25 MIPS throughput.

Does the C8051F851-C-GU support in-system programming?

Yes, the device features 8 kB of Flash memory that is in-system programmable in 512-byte sectors.

What analog peripherals are included in this microcontroller?

It includes a 12-bit Analog-to-Digital Converter (ADC) with up to 16 input channels and two low-current analog comparators with programmable hysteresis.