C8051F921-F-GM

Overview

The C8051F921-F-GM is an 8-bit microcontroller from the Silicon Labs C8051F92x series, featuring a high-speed CIP-51 core operating at up to 25 MHz. It integrates 32 kB of in-system programmable Flash memory and 4352 bytes of internal data RAM. The device supports a supply voltage range of 0.9 V to 3.6 V, utilizing a built-in DC-DC converter for one-cell mode operation. Key peripherals include a 10-bit SAR ADC with 300 ksps throughput, two comparators, and multiple digital interfaces such as SMBus, SPI, and UART.

Feature Summary

• Integrated hardware SmaRTClock oscillator supporting real-time clock functions with low power consumption
• Built-in DC-DC converter enabling efficient single-battery operation down to 0.9 V
• On-chip debug circuitry facilitating full-speed, non-intrusive in-system debugging without external emulators
• Flexible interrupt handler with expanded capabilities and priority levels

Applications

• Single or dual battery powered portable devices
• Industrial control systems requiring robust analog signal processing
• Smart metering applications with precise voltage monitoring
• Low-power embedded controllers needing real-time clock functionality

Procurement Notes

Verify the specific suffix '-F' against the manufacturer's latest documentation to confirm temperature grade and package variant. Ensure compatibility with existing PCB footprints for the QFN package. Cross-reference the part number with official Silicon Labs distributors to confirm current production status and availability. Check for any recent product change notices affecting assembly or labeling.

Selection Notes

Select this component when a balance of moderate Flash capacity and extensive analog peripherals is required. The C8051F921 offers sufficient I/O and timer resources for complex control loops while maintaining low power characteristics. Consider the F-GM package for surface mount applications requiring hand-solderability options if using the LQFP variant, though this specific part uses QFN. Evaluate the need for the integrated DC-DC converter if operating strictly within the 0.9 V to 1.8 V range.

Part Context

This MCU belongs to the C8051F9xx family, designed for mixed-signal applications. It shares architectural similarities with the C8051F93x series but differs in Flash size (32 kB vs 64 kB). The CIP-51 core provides enhanced performance over standard 8051 architectures through pipelined instruction execution. The device is part of Silicon Labs' portfolio targeting cost-sensitive, battery-operated embedded systems.

Replacement Considerations

The C8051F931-F-GM serves as a direct functional substitute with increased Flash memory (64 kB) while maintaining identical pinouts and peripheral sets. Verify software compatibility regarding memory mapping and linker scripts when migrating between these variants.