The Silicon Labs C8051F816-GSR delivers an integrated 8-bit microcontroller solution built on the proven 8051 architecture, combining analog sensing, capacitive touch capability, and flexible communication interfaces in a compact 16-SOIC surface-mount package. Operating at up to 25MHz with 8KB of flash program memory and 512 bytes of RAM, this device targets cost-sensitive embedded applications where moderate processing performance, mixed-signal integration, and low pin count are prioritized.
Flash memory is organized as 8K × 8, providing non-volatile program storage with in-system programmability. The 512-byte RAM allocation supports stack operations, variable storage, and buffering for typical control and sensor interface tasks. A 12-channel, 10-bit successive-approximation ADC enables direct connection to analog sensors, transducers, and signal conditioning circuits without external conversion hardware. The internal voltage reference and temperature sensor reduce bill-of-materials overhead in thermal monitoring or calibration-dependent designs.
Capacitive touch sensing is implemented through dedicated peripheral hardware, allowing direct measurement of capacitance changes on input pins for human interface applications such as buttons, sliders, or proximity detection. This eliminates the need for external touch controller ICs in user interface designs where a small number of touch inputs are sufficient.
Communication options include SMBus and I²C on a shared two-wire interface, SPI for high-speed synchronous data exchange, and a full UART/USART for asynchronous serial links. These interfaces support connection to external memory, displays, sensor modules, wireless transceivers, and host processors. The combination of protocols in a single device simplifies board design when interfacing with multiple subsystems or supporting legacy serial communication standards.
Thirteen general-purpose I/O pins provide digital control, interrupt inputs, and peripheral signal routing. PWM outputs are available for motor control, LED dimming, or analog signal synthesis through external filtering. A watchdog timer enhances system reliability by providing automatic recovery from software faults or transient events. Power-on reset circuitry ensures defined startup behavior without external supervisor components.
The supply voltage range of 1.8V to 3.6V accommodates battery-powered designs, including single-cell lithium systems and multi-cell alkaline or NiMH configurations. Low-voltage operation also supports integration with modern digital logic families and low-power system architectures. An internal oscillator eliminates the requirement for external crystal or resonator components, reducing cost and board area while maintaining adequate timing accuracy for communication protocols and control loop execution.
Thermal specifications cover -40°C to +85°C ambient operation, suitable for industrial instrumentation, automotive auxiliary systems, and outdoor equipment. The 16-SOIC package, with 3.90mm body width, fits standard PCB footprints and supports automated assembly with tape-and-reel packaging. Moisture sensitivity level 3 allows 168 hours of exposure at 30°C and 60% relative humidity after bag opening, compatible with typical manufacturing floor conditions and batch processing workflows.
The C8051F816-GSR is currently designated Last Time Buy, indicating the manufacturer's intent to discontinue active production. Design teams incorporating this part should evaluate long-term availability, secure inventory for product lifecycle requirements, and assess migration paths to current-generation alternatives within the C8051 family or comparable 8-bit microcontroller platforms. RoHS3 compliance confirms restriction-of-hazardous-substances conformance for commercial and industrial distribution in regulated markets.
C8051F816-GSR (1)
Replacement Pressure Around the Silicon Labs C8051F816-GSR 8-Bit MCU
The Silicon Labs C8051F816-GSR is often considered for replacement because it is marked as Last Time Buy, while many deployed designs still depend on its 8051 core, 16-SOIC package, low-voltage operation, mixed-signal peripherals, and serial interfaces. Selecting an equivalent or alternative part is not only a matter of matching flash size or pin count. Firmware architecture, peripheral behavior, ADC resolution, operating voltage, package footprint, programming flow, and production availability all affect whether a replacement can be used with minimal redesign.
Common replacement paths include:
| Replacement Type | Candidate Part Number | Manufacturer | Replacement Position |
|---|---|---|---|
| Closest ordering-code equivalent |
C8051F816-GS
Energy Micro (Silicon Labs)
IC MCU 8BIT 8KB FLASH 16SOIC
22574
| Silicon Labs | Same base MCU in 16-SOIC, typically considered when tape-and-reel format is not required |
| Functional alternative |
ATTINY167-MMUR
Microchip Technology
IC MCU 8BIT 16KB FLASH 20WQFN
3406
| Microchip Technology | 8-bit MCU alternative with different architecture, package, voltage range, and firmware requirements |
For a C8051F816-GSR replacement, the first step is to separate direct procurement substitution from engineering redesign.
C8051F816-GS
is the closer option when the goal is to preserve the Silicon Labs C8051F816 hardware and firmware platform.
C8051F816-GS
Energy Micro (Silicon Labs)
IC MCU 8BIT 8KB FLASH 16SOIC
22574
ATTINY167-MMUR
may be considered when the design can tolerate PCB, firmware, and validation changes.
ATTINY167-MMUR
Microchip Technology
IC MCU 8BIT 16KB FLASH 20WQFN
3406
What the Silicon Labs C8051F816-GSR Provides in the Original Design
The Silicon Labs C8051F816-GSR is an 8051-based 8-bit microcontroller from the C8051F81x series. It integrates 8KB flash, 512 bytes RAM, a 25MHz core, and mixed-signal peripherals in a 16-SOIC surface-mount package. Its operating voltage range of 1.8V to 3.6V makes it suitable for low-voltage embedded control circuits, especially where the MCU interfaces directly with 3.3V logic or battery-powered subsystems.
| Parameter | C8051F816-GSR Characteristics | Replacement Impact |
|---|---|---|
| Core architecture | 8051, 8-bit | Firmware written for Silicon Labs 8051 peripherals will not directly port to non-8051 MCUs |
| Maximum speed | 25MHz | Alternatives should be checked for timing-sensitive control loops, communication timing, and interrupt response |
| Program memory | 8KB flash | Replacement must support existing code size plus any porting overhead |
| RAM | 512 x 8 | Small RAM footprint may simplify replacement, but stack usage and peripheral buffers must be reviewed |
| Supply voltage | 1.8V to 3.6V | Alternatives with higher minimum voltage may not work in low-voltage systems |
| Interfaces | SMBus/I2C, SPI, UART/USART | Replacement must support required communication protocols with compatible electrical levels |
| Peripherals | Capacitive sense, POR, PWM, temperature sensor, watchdog timer | Integrated functions may reduce external components; substitutes must replicate required functions |
| ADC | 12-channel, 10-bit ADC | Analog channel count, reference behavior, and input mapping affect board-level compatibility |
| GPIO | 13 I/O | Pin availability and alternate-function routing must be compared, not only total I/O count |
| Package | 16-SOIC, 3.90mm width | Mechanical compatibility favors SOIC alternatives; QFN alternatives require PCB redesign |
| Temperature range | -40°C to 85°C | Replacement must match application environment and qualification expectations |
| Packaging | Tape & Reel | Production line requirements may require the same or compatible packaging format |
The C8051F816-GSR is commonly used in compact embedded control, sensor interface, capacitive touch input, low-power monitoring, serial communication nodes, simple motor or actuator control, and mixed-signal control boards. Its value in an existing design often comes from the combination of 8051 firmware compatibility, integrated analog functions, and a hand-solderable or production-friendly 16-SOIC package.
When evaluating a C8051F816-GSR equivalent, the strongest candidates are those that preserve the package, voltage range, peripheral set, and development environment. If any of these differ, the replacement becomes a redesign decision rather than a drop-in substitution.
Engineering Review of C8051F816-GSR Replacement Candidates
The following table compares the main available replacement directions for the Silicon Labs C8051F816-GSR. The
C8051F816-GS
is the closest part-number-level substitute because it retains the same base device. The
C8051F816-GS
Energy Micro (Silicon Labs)
IC MCU 8BIT 8KB FLASH 16SOIC
22574
ATTINY167-MMUR
is a functional alternative, not a direct equivalent, and should be evaluated as a redesign option.
ATTINY167-MMUR
Microchip Technology
IC MCU 8BIT 16KB FLASH 20WQFN
3406
| Manufacturer | Part Number | Key Specifications | Product Features | Typical Applications | Why It Can Replace the Original Part | Main Differences or Limitations | Recommended Usage |
|---|---|---|---|---|---|---|---|
| Silicon Labs |
C8051F816-GS
Energy Micro (Silicon Labs)
IC MCU 8BIT 8KB FLASH 16SOIC
22574
| 8051 core, 8-bit, 25MHz, 8KB flash, 512B RAM, 1.8V to 3.6V, 13 I/O, 10-bit ADC, 16-SOIC | Same C8051F816 base MCU, internal oscillator, SMBus/I2C, SPI, UART/USART, PWM, watchdog, POR, capacitive sensing, temperature sensor | Existing C8051F816 embedded control boards, sensor modules, capacitive-touch interfaces, low-voltage serial control circuits | It uses the same base product number as C8051F816-GSR and preserves the silicon platform, package family, voltage range, and firmware architecture | Packaging format may differ from C8051F816-GSR; availability should be confirmed because the product family is Last Time Buy | Preferred option when maintaining the original PCB, firmware, programming process, and qualification base |
| Microchip Technology |
ATTINY167-MMUR
Microchip Technology
IC MCU 8BIT 16KB FLASH 20WQFN
3406
| AVR 8-bit MCU, 16KB flash class, SRAM/EEPROM depending on device configuration, multiple timers, ADC, serial communication support, QFN/MLF-style package | AVR architecture, higher flash capacity than C8051F816-GSR, automotive-oriented ATTINY167 family options, compact package, timer/PWM functions, analog inputs | Redesigned small embedded controllers, automotive-style control nodes, actuator control, sensor interfaces, LIN/serial communication designs | It can perform many similar 8-bit MCU control tasks, including digital I/O, ADC-based sensing, PWM output, and serial communication | Not pin-compatible, not code-compatible, different package, different toolchain, different peripheral registers, and likely different supply-voltage behavior; PCB and firmware redesign are required | Suitable when the C8051F816-GSR is unavailable and the project can absorb schematic, PCB, firmware, and validation changes |
For designs already released to production,
C8051F816-GS
is the lowest-risk path if inventory can be secured. It keeps the replacement evaluation focused on ordering code, packaging, and supply-chain availability rather than electrical redesign.
C8051F816-GS
Energy Micro (Silicon Labs)
IC MCU 8BIT 8KB FLASH 16SOIC
22574
ATTINY167-MMUR
should be treated differently. Although it is an 8-bit MCU with enough functional overlap for many control tasks, it belongs to a different architecture and package ecosystem. Existing 8051 firmware cannot be reused directly, and peripheral behavior must be reimplemented using the AVR register model and Microchip development tools. It may offer more program memory headroom, but that advantage only matters if the redesign budget allows firmware migration and board re-layout.
ATTINY167-MMUR
Microchip Technology
IC MCU 8BIT 16KB FLASH 20WQFN
3406
Practical Trade-Offs When Comparing C8051F816-GS and ATTINY167-MMUR as C8051F816-GSR Alternatives
A useful C8051F816-GSR replacement comparison should focus on the amount of engineering change required. The closest match is not always the cheapest part number; it is the option that reduces requalification effort, firmware risk, PCB changes, and production disruption.
| Evaluation Factor | C8051F816-GS | ATTINY167-MMUR | Engineering Interpretation |
|---|---|---|---|
| Electrical compatibility | Closely aligned with C8051F816-GSR because it is the same base MCU family | Requires full electrical review due to different MCU family and likely different pinout/package |
C8051F816-GS
Energy Micro (Silicon Labs)
IC MCU 8BIT 8KB FLASH 16SOIC
22574
ATTINY167-MMUR
Microchip Technology
IC MCU 8BIT 16KB FLASH 20WQFN
3406
|
| Mechanical compatibility | 16-SOIC package alignment supports existing PCB use | QFN/MLF-style package requires PCB footprint redesign | If the board cannot change,
ATTINY167-MMUR
Microchip Technology
IC MCU 8BIT 16KB FLASH 20WQFN
3406
|
| Firmware compatibility | Existing Silicon Labs 8051 code base is largely preserved | Requires porting from 8051 to AVR architecture | Firmware migration effort is the largest limitation of
ATTINY167-MMUR
Microchip Technology
IC MCU 8BIT 16KB FLASH 20WQFN
3406
|
| Peripheral compatibility | SMBus/I2C, SPI, UART/USART, ADC, PWM, watchdog, capacitive sensing remain within the same device platform | Similar control functions may be possible, but peripheral implementation differs | Functional equivalence must be proven at register, timing, and interrupt levels |
| Supply voltage fit | Maintains the 1.8V to 3.6V operating range of the original | Must be checked against the exact
ATTINY167-MMUR
Microchip Technology
IC MCU 8BIT 16KB FLASH 20WQFN
3406
| Low-voltage systems favor
C8051F816-GS
Energy Micro (Silicon Labs)
IC MCU 8BIT 8KB FLASH 16SOIC
22574
|
| Analog performance | Preserves the original 10-bit ADC structure and channel expectations | ADC capability may be suitable, but channel mapping and reference behavior differ | Analog front-end validation is required for
ATTINY167-MMUR
Microchip Technology
IC MCU 8BIT 16KB FLASH 20WQFN
3406
|
| Production impact | Lower impact if packaging and availability match procurement needs | Higher impact due to redesign, programming changes, and new inspection criteria |
C8051F816-GS
Energy Micro (Silicon Labs)
IC MCU 8BIT 8KB FLASH 16SOIC
22574
ATTINY167-MMUR
Microchip Technology
IC MCU 8BIT 16KB FLASH 20WQFN
3406
|
| Reliability and qualification | Existing qualification data may remain partly applicable | Requires new validation across temperature, EMC, programming, and functional behavior |
ATTINY167-MMUR
Microchip Technology
IC MCU 8BIT 16KB FLASH 20WQFN
3406
|
| Cost considerations | Unit cost may be affected by Last Time Buy status and availability | May offer sourcing flexibility, but redesign cost can exceed component savings | Total cost should include engineering time, PCB changes, firmware work, and testing |
| Best-fit scenario | Existing product maintenance, repair builds, production continuation | New PCB revision or platform migration where AVR architecture is acceptable | Choose based on lifecycle strategy, not only device availability |
| Main advantage | Closest C8051F816-GSR equivalent path | Potentially more flash and broader redesign flexibility | The advantage depends on whether the design needs continuity or migration |
| Main limitation | Availability may be constrained by lifecycle status | Not a drop-in replacement | Procurement risk versus redesign risk should guide selection |
For a board that must remain electrically, mechanically, and firmware compatible with the Silicon Labs C8051F816-GSR,
C8051F816-GS
is the more appropriate replacement part number to investigate first. It minimizes changes to the 8051 firmware environment, 16-SOIC layout, peripheral configuration, and low-voltage operating assumptions.
C8051F816-GS
Energy Micro (Silicon Labs)
IC MCU 8BIT 8KB FLASH 16SOIC
22574
For a design revision where the MCU can be changed,
ATTINY167-MMUR
may be considered as an alternative 8-bit microcontroller. The decision should include a review of I/O mapping, ADC inputs, PWM channels, serial communication requirements, oscillator accuracy, programming interface, package assembly capability, and software migration effort.
ATTINY167-MMUR
Microchip Technology
IC MCU 8BIT 16KB FLASH 20WQFN
3406
Before committing to any C8051F816-GSR equivalent or alternative, confirm datasheets, package drawings, lifecycle status, and available stock. For quotations and sourcing support for C8051F816-GSR replacement parts such as
C8051F816-GS
and
C8051F816-GS
Energy Micro (Silicon Labs)
IC MCU 8BIT 8KB FLASH 16SOIC
22574
ATTINY167-MMUR
, visit IC-Components.com or email Info@IC-Components.com.
ATTINY167-MMUR
Microchip Technology
IC MCU 8BIT 16KB FLASH 20WQFN
3406
