C8051F045 - 25MHz 8-Bit MCU, 64KB Flash, 64-TQFP | Silicon Labs
MPN: C8051F045 ✓ ActiveC8051F045 Overview
A microcontroller is a programmable integrated circuit containing a processor core, memory, peripherals, and interface logic on one semiconductor device. The C8051F045 belongs to the C8051F04x family of 8-bit microcontrollers, combining an 8051-compatible core with embedded flash, RAM, digital I/O, communication peripherals, and other mixed-signal resources. Within the product hierarchy, it is a microcontroller, embedded controller, and semiconductor intended for compact standalone control and communication tasks.
The verified product information identifies a 25 MHz maximum operating frequency, 64 KB flash program memory, 4.25 KB RAM, and 2.7 V to 3.6 V supply range. Its 64-pin TQFP package provides substantially more connection options than smaller microcontroller packages and is appropriate for designs requiring external memory interfaces, communications, analog inputs, timers, or a larger number of general-purpose I/O pins. The listed C8051F045-GQ ordering option is identified as a RoHS-compliant, lead-free 64-TQFP variant.
The C8051F045 architecture is positioned for embedded control rather than high-performance computing. Its 25 MHz clock provides deterministic operation for motor, machine, interface, and communications tasks, while the 64 KB flash region supports a larger embedded program than small-memory 8051 devices. The verified listing identifies CAN capability in the C8051F04x family, allowing the controller to participate in industrial and automotive networking designs when the remaining peripheral, transceiver, and timing requirements are satisfied.
Typical applications include CAN-connected industrial controllers, automated test equipment, building-control modules, embedded data-acquisition units, instrumentation, and communication gateways. In a CAN node, the microcontroller executes application logic, handles digital inputs, controls outputs, and communicates through a separate CAN transceiver. The 64-TQFP package also makes the device practical for designs that need more peripheral access than a small 20- or 32-pin MCU can provide.
Designers should verify the complete pin assignment and peripheral availability against the manufacturer datasheet before layout because the supplied search results establish the package size and pin count but do not provide a complete numbered pin table. The 3.3 V supply range also requires careful regulator selection, while CAN implementation depends on correct transceiver selection, bus termination, isolation requirements, and software timing.
This page consolidates the verified distributor specifications, package information, availability observations, and engineering-oriented application guidance into one practical reference. It also separates directly verified facts from unavailable details so engineers can identify what still requires confirmation in the complete C8051F04x technical documentation.
Drop-in alternatives for C8051F045 — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
C8051F045-GQ
✅ Drop-In📋 Reference alternative (not in catalog)
C8051F040
✅ Drop-In ⚠️ Specs UnverifiedContact for price
View Datasheet →C8051F041
✅ Drop-In ⚠️ Specs UnverifiedContact for price
View Datasheet →C8051F042
✅ Drop-In ⚠️ Specs UnverifiedContact for price
View Datasheet →C8051F043
✅ Drop-In ⚠️ Specs UnverifiedContact for price
View Datasheet →C8051F044
✅ Drop-In ⚠️ Specs UnverifiedContact for price
View Datasheet →C8051F045 Maximum Ratings & Electrical Characteristics
| Microcontroller Type | 8-bit microcontroller |
| Architecture | 8051-compatible |
| Series | C8051F04x |
| Maximum Clock Frequency | 25 MHz |
| Program Memory Type | Flash |
| Program Memory Size | 64 KB (64K x 8) |
| RAM Size | 4.25 KB (4.25K x 8) |
| Supply Voltage Range | 2.7 V to 3.6 V |
| CAN Interface | Yes |
| Package | 64-TQFP (10 x 10 mm) |
| Pin Count | 64 pins |
| Mounting Type | Surface mount |
| Core Count | 1 core |
| RoHS Status | Compliant for the listed C8051F045-GQ ordering option |
C8051F045 64-tqfp (10 x 10 mm) Pin Configuration Guide
Pin configuration for C8051F045 (64-tqfp (10 x 10 mm) package). This digital IC includes GPIO, communication interfaces (UART, SPI, I2C), and power pins. Refer to the manufacturer datasheet for alternate pin functions and configuration options. Essential for embedded system design and PCB layout.
No detailed pinout data available for C8051F045.
Refer to the datasheet for full pin configuration.
Typical Applications
C8051F045 is suitable for 6 applications: CAN-Connected Industrial Control, Automated Test Equipment, Building Control and HVAC Equipment, Embedded Data Acquisition, Instrumentation and Measurement Front Ends, Communication Gateways.
CAN-Connected Industrial Control
The C8051F045 fits CAN-connected industrial controllers because it combines a 25 MHz 8-bit core, 64 KB of flash, 4.25 KB of RAM, and CAN support in a 3.3 V operating range. The controller can execute sequencing logic, supervise digital inputs, drive outputs, and exchange process data while an external transceiver handles the physical bus. Its 64-pin TQFP package provides access to substantially more I/O and peripheral resources than a small controller package. Before layout, engineers should confirm the exact pin assignment and peripheral multiplexing in the manufacturer documentation. Firmware should also include bus-off handling, fault counters, timeout behavior, and safe-state outputs so the external CAN interface remains predictable during network errors.
Recommended
Automated Test Equipment
The C8051F045 is suitable for embedded automated-test equipment that needs deterministic control, substantial flash space, and many accessible signals. Its 25 MHz clock supports responsive sequencer logic, while 64 KB of flash accommodates test programs and 4.25 KB of RAM can hold temporary measurements and state information. The 64-TQFP package can expose measurement-control I/O, communication interfaces, and peripheral inputs without requiring a companion programmable-logic device. In such a system, the MCU coordinates stimuli, reads results, and reports status through a communications interface. The principal engineering trade-off is that a 25 MHz 8-bit architecture offers less parallel processing than a modern 32-bit MCU, so workload partitioning and deterministic interrupt design remain important.
Recommended
Building Control and HVAC Equipment
The C8051F045 can serve as the central controller in building-control, HVAC, or environmental-control equipment where many digital and analog functions must be coordinated. Its 64 KB flash provides room for control algorithms, schedules, diagnostics, and communication firmware, while 4.25 KB of RAM supports buffers and operating state. The 2.7 V to 3.6 V supply range fits regulated 3.3 V control boards, and the 64-pin package leaves more I/O available for sensors, relays, and bus interfaces than compact MCUs. A production design should define fail-safe states for power loss, actuator faults, and sensor failure. The complete electrical characteristics and exposed-pin functions must be verified against the manufacturer datasheet before assigning sensitive analog or high-current outputs.
Recommended
Embedded Data Acquisition
The C8051F045 is appropriate for compact embedded data-acquisition units that must gather sensor information, execute control calculations, and store or transmit results. Its 25 MHz clock provides useful throughput for sampling coordination and protocol handling, while 64 KB of flash and 4.25 KB of RAM allow meaningful local buffering without immediately requiring external memory. The 64-pin TQFP package offers more peripheral choices for sensors and communications than smaller 8-bit devices. In an acquisition design, the MCU should configure analog and digital inputs, timestamp measurements, apply calibration, and flag out-of-range data. Exact ADC resolution, reference behavior, and analog timing were not present in the supplied search snippets, so those functions must be confirmed in the complete datasheet before the MCU is approved for precision measurement.
Recommended
Instrumentation and Measurement Front Ends
The C8051F045 is a practical fit for instrumentation front ends that combine control logic, communication, and a moderate amount of embedded code. Its 64 KB flash can store calibration tables, menus, diagnostics, and protocol handlers, while 4.25 KB of RAM supports working buffers. At 25 MHz, the 8-bit core is well suited to deterministic supervisory tasks, and the 64-pin package offers a broad connection count for display, keys, measurement circuitry, and communications. For laboratory or process instrumentation, designers should add suitable input protection and isolation where required, and should not infer analog precision from the generic family listing. The verified information confirms the microcontroller's clock, memory, supply, CAN capability, and package, but the complete pin-level and analog electrical details remain prerequisites for final schematic sign-off.
Recommended
Communication Gateways
The C8051F045 can implement a compact gateway that bridges a CAN segment with another serial, industrial, or Ethernet-oriented interface. Its 25 MHz core is sufficient for protocol translation, while 64 KB of flash accommodates multiple stack configurations and 4.25 KB of RAM provides packet and message buffers. The 64-TQFP package gives a gateway designer access to a wide set of I/O and peripheral functions without immediately adding a larger processor. A practical implementation should use DMA or interrupt-driven reception where available, apply frame-length and timeout checks, and isolate external circuitry where the communication environment is noisy. The exact peripheral inventory, package pin multiplexing, and electrical limits must be checked in the full Silicon Labs documentation before finalizing a gateway schematic or firmware architecture.
Recommended
Recommended Products Summary
Engineering reference data for C8051F045 — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | C8051F045-GQ | C8051F040 | C8051F041 | C8051F042 |
|---|---|---|---|---|---|
| Manufacturer | Silicon Labs | Silicon Labs | Silicon Labs | Silicon Labs | Silicon Labs |
| Package | 64-TQFP (10 x 10 mm) | 64-TQFP (10 x 10 mm) | 64-TQFP (10 x 10 mm) | 64-TQFP (10 x 10 mm) | 64-TQFP (10 x 10 mm) |
| Architecture | 8-bit 8051-compatible | 8-bit 8051-compatible | 8-bit C8051F04x family | 8-bit C8051F04x family | 8-bit C8051F04x family |
Key Differentiators
- Directly documented replacement ordering option (vs C8051F045-GQ)
- Established 3.3 V-class operating range (vs C8051F040)
- Moderate code and working-memory capacity (vs C8051F041)
- Integrated CAN connectivity (vs C8051F042)
Design Notes
Do not route the PCB until the complete C8051F045 pinout and alternate-function mapping have been checked in the manufacturer datasheet. The verified records establish a 64-pin 10 x 10 mm TQFP, but they do not expose individual pin assignments for power, ground, reset, programming, clock, and communications. Confirm exposed versus routed pins, required decoupling, programming signals, and every peripheral's alternate-function location before releasing the layout.
Design the supply for the verified 2.7 V to 3.6 V operating range, including startup and transient margin. Place local bulk and high-frequency decoupling capacitors close to the device's supply and ground pins, and provide a low-impedance return path for every switching current. Exact capacitor values and pin locations must follow the manufacturer's recommended layout because the supplied data does not specify capacitor requirements or absolute maximum ratings.
For a CAN implementation, keep the MCU and transceiver interface short and place protection components near the connector or transceiver rather than at the controller. Use a continuous ground reference, separate noisy switching returns from sensitive signal paths, and follow the transceiver manufacturer's guidance for bus topology and termination. The C8051F045's 25 MHz clock allows plenty of processing headroom, but protocol timing still depends on a deterministic interrupt structure and verified peripheral clock configuration.
Estimated thermal and power checks cannot be completed from the supplied information because the device's operating current and thermal resistance were not provided. Use the manufacturer maximum-current and thermal data with the actual clock, enabled peripherals, and package layout. Validate worst-case ambient temperature and output activity in the assembled board; do not reuse the listed distributor price or memory capacity as evidence of power performance.
Compliance Information
RoHS-compliant and lead-free status was explicitly reported for the C8051F045-GQ ordering option in the verified TrustCompo listing. No verified REACH, halogen-free, AEC-Q100, or conflict-minerals statement was supplied for the base MPN.
