C8051F321R

Overview

The C8051F321R is an 8-bit mixed-signal microcontroller from Silicon Labs, featuring a high-speed 8051 core with up to 25 MIPS throughput at a 25 MHz clock. It integrates 16 KB of in-system programmable Flash memory and 2304 bytes of internal RAM. The device includes a full-speed USB 2.0 function controller with an integrated transceiver and on-chip clock recovery, eliminating the need for external components. Analog peripherals consist of a 10-bit ADC supporting up to 200 ksps, two comparators, and a temperature sensor. Digital interfaces include SPI, UART, and SMBus. It operates within a voltage range of 2.7V to 3.6V (with regulator input up to 5.25V) and supports a temperature range of -40°C to +85°C.

Feature Summary

• Integrated full-speed USB 2.0 controller with built-in transceiver and clock recovery for simplified connectivity.
• High-performance 8051 CPU executing up to 70% of instructions in one or two system clocks.
• On-chip debug circuitry enabling non-intrusive in-system debugging without external emulators.
• Mixed-signal integration including a 10-bit ADC, analog comparators, and precision internal oscillator.

Applications

• Embedded USB communication devices
• Data acquisition systems
• Portable instruments
• Industrial control interfaces

Procurement Notes

Verify the specific suffix 'R' indicates tape and reel packaging configuration as per manufacturer standards. Confirm RoHS compliance status and lead times directly with authorized distributors, as component availability may vary. Ensure the selected package variant matches the required PCB footprint and thermal management specifications for the target application environment.

Selection Notes

Select this model when a single-chip USB solution is required without external PHY components. The C8051F321R offers a compact MLP-28 package compared to the LQFP-32 option in the same family. Consider the 16 KB Flash size and 2304-byte RAM allocation against application memory requirements. Verify that the 25 MHz maximum frequency meets real-time processing needs.

Part Context

This component belongs to the C8051F32x/34x family of USB microcontrollers designed by Silicon Labs. These devices are part of the broader C8051F series, known for their fully integrated mixed-signal capabilities. The C8051F321R specifically utilizes the MLP-28 package, distinguishing it from the LQFP-32 packaged C8051F320 within the same functional group.

Replacement Considerations

Consult official Silicon Labs documentation for current lifecycle status and recommended alternatives if this part is discontinued. Verify pin compatibility and software register mapping before substituting with other members of the C8051F32x/34x family or newer 8-bit MCU generations.

FAQ

Does the C8051F321R require an external crystal for USB operation?

No, the device features an integrated clock recovery mechanism that allows full-speed USB operation without an external crystal.

What is the maximum sampling rate of the onboard ADC?

The 10-bit Analog-to-Digital Converter supports a maximum sampling rate of 200 ksps.