C8051F851-C-IM

Overview

The C8051F851-C-IM is an 8-bit microcontroller from the Silicon Labs C8051F85x/86x family, featuring a high-speed CIP-51 core operating at up to 25 MHz. It integrates 8 kB of in-system programmable flash memory and 512 bytes of RAM. The device includes a 12-bit ADC with up to 16 channels, two analog comparators, and communication peripherals such as UART, I2C/SMBus, and SPI. It operates on a supply voltage of 2.2 V to 3.6 V within a temperature range of -40 °C to +125 °C.

Feature Summary

• High-speed CIP-51 core delivering up to 25 MIPS throughput using a standard 8051 instruction set.
• Integrated 12-bit Analog-to-Digital Converter supporting up to 16 input channels with internal or external reference options.
• On-chip debug circuitry enabling full-speed, non-intrusive in-system debugging without external emulators.
• Dual low-power oscillators providing calibrated high-frequency and independent low-frequency clock sources.

Applications

• Industrial control systems requiring robust analog signal processing.
• Battery-powered devices utilizing low-power oscillator modes.
• Embedded applications needing integrated communication interfaces like UART and SMBus.
• Automotive modules qualified to AEC-Q100 standards.

Procurement Notes

Verify the specific suffix 'C-IM' confirms the industrial temperature grade (-40 °C to +125 °C) and QFN package variant. Confirm RoHS compliance status for the current production lot. Check for 'Not Recommended for New Designs' notices in the latest datasheet revision before finalizing procurement plans.

Selection Notes

Select this component when an 8-bit MCU with integrated analog peripherals and debug capabilities is required. Ensure the 8 kB flash and 512-byte RAM meet application memory constraints. Verify that the 2.2 V to 3.6 V supply range aligns with the system power architecture and that the QFN package fits the PCB layout constraints.

Part Context

This part belongs to the C8051F85x/86x series, which offers low-cost 8-bit solutions with mixed-signal capabilities. The family shares architectural similarities but varies in memory size and peripheral counts. The C8051F851 specifically provides a balanced configuration of flash, RAM, and analog features suitable for general-purpose embedded control tasks.

Replacement Considerations

Public confirmed substitute: EFM8BB51F8I-C-QFN20R. Note that this alternative belongs to the EFM8BB51 family and may require software adaptation due to architectural differences between CIP-51 and EFM8 cores.

FAQ

What are the available clock sources for the C8051F851?

The device supports an internal high-frequency oscillator (calibrated to 24.5 MHz), an internal low-frequency oscillator (80 kHz nominal), and an external clock input.

How is the flash memory programmed?

The flash memory is in-system programmable in 512-byte sectors and can be written via the C2 interface or during manufacturing programming.