C8051F921-F-GMR

Overview

The C8051F921-F-GMR is an 8-bit microcontroller from the Silicon Labs C8051F9xx series, featuring a 25 MHz high-speed CIP-51 CPU core. It integrates 32 kB of in-system programmable Flash memory and 4352 bytes of internal data RAM. The device operates within a supply voltage range of 0.9 V to 3.6 V, supporting single-cell (0.9–1.8 V) and dual-cell (1.8–3.6 V) battery applications via a built-in DC-DC converter and LDO regulator. Key peripherals include a 10-bit SAR ADC with up to 23 external inputs, two comparators, multiple serial interfaces (SMBus, SPI, UART), and four general-purpose timers.

Feature Summary

• Ultra-low power operation with integrated DC-DC converter enabling efficient single-cell battery usage
• High-performance 8051-compatible core delivering up to 25 MIPS throughput
• Integrated 10-bit analog-to-digital converter with burst mode and auto-averaging accumulator
• Flexible I/O architecture with 5 V tolerant ports and hardware crossbar decoder

Applications

• Battery-powered portable instrumentation
• Single or dual-cell battery operated devices
• Industrial control systems requiring low standby current
• Smart sensor nodes with capacitive touch sensing

Procurement Notes

Verify the specific suffix 'F' indicates the operating temperature range and package variant against the manufacturer's official ordering guide. Confirm that the 'GMR' suffix corresponds to the tape and reel packaging format required for automated assembly processes. Ensure compatibility with existing design files regarding pinout and electrical characteristics before finalizing procurement orders.

Selection Notes

Select this component when system requirements demand ultra-low sleep currents combined with fast wake-up times from a single lithium cell. The integrated DC-DC converter makes it suitable for applications where input voltage varies significantly during discharge cycles. Consider the 32 kB Flash capacity for firmware size constraints and verify that the 24 available I/O pins meet the interface requirements for sensors and communication buses.

Part Context

This part belongs to the C8051F92x/93x family of mixed-signal microcontrollers designed for low-power embedded applications. The F92x sub-series specifically provides 32 kB of Flash memory, distinguishing it from the 64 kB F93x variants. The family is characterized by its ability to operate at voltages as low as 0.9 V, making it distinct from standard 3.3 V or 5 V logic families.

Replacement Considerations

Direct substitutes within the same family include the C8051F93x series if higher Flash capacity is acceptable. Verify pin compatibility and software register mapping when considering migration between different Flash sizes within the C8051F9xx series.