C8051F921-GMR

Overview

The C8051F921-GMR is an 8-bit microcontroller from the Silicon Labs C8051F9xx series, featuring a 25 MHz high-speed CPU core. 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 single-cell operation. Key peripherals include a 10-bit ADC with up to 23 inputs, two comparators, multiple serial ports (SMBus, SPI, UART), and a SmaRTClock real-time clock.

Feature Summary

• Operates on a single cell battery or dual-cell configuration with integrated power management circuitry
• Includes a 10-bit SAR ADC with burst mode and auto-averaging accumulator for enhanced resolution
• Features a hardware SmaRTClock oscillator that functions at ultra-low voltages with minimal current consumption
• Provides full-speed non-intrusive on-chip debug capabilities without requiring external emulator hardware

Applications

• Battery-powered sensor nodes requiring extended operational life
• Portable medical devices necessitating low-voltage operation
• Industrial monitoring systems utilizing capacitive touch sensing
• Wearable electronics with strict space and power constraints

Procurement Notes

Verify the specific suffix 'GMR' corresponds to the tape-and-reel packaging format required for automated assembly processes. Confirm the device revision matches the design specifications, as errata documents may outline silicon revisions affecting certain peripheral behaviors. Ensure the ordering part number aligns with the exact memory capacity and package dimensions specified in the final schematic.

Selection Notes

Select this component when designing systems that require operation below 1.8 V using a single lithium cell. The integrated DC-DC converter makes it suitable for applications where standard LDO regulators would be inefficient. Choose this model over higher-memory variants if the application logic fits within the 32 kB Flash constraint while maintaining the same peripheral set and package footprint.

Part Context

This microcontroller belongs to the C8051F9xx family, which distinguishes itself through ultra-low power capabilities and wide voltage tolerance. Unlike standard 8051 cores, the CIP-51 architecture offers improved instruction throughput. The F921 variant specifically provides half the Flash memory of the F931 sibling while retaining identical analog and digital peripheral configurations.

Replacement Considerations

C8051F931-GMR: Offers double the Flash memory (64 kB) with identical pinout and peripherals.