Silicon Labs C8051F835-GS

Overview

C8051F835-GS from Silicon Laboratories is a mixed-signal ISP Flash MCU with integrated Capacitance-to-Digital Converter (CDC), 10-bit ADC, and high-speed 8051 core. It delivers 25 MIPS at 25 MHz, supports up to 16 capacitive sensing channels with 40 μs conversion time and 16-bit resolution, and operates from 1.8–3.6 V in industrial temperature range (–40 to +85 °C). It is used in touch-enabled human interface devices such as appliance control panels and interactive kiosks.

For engineers reviewing the C8051F835-GS datasheet, C8051F835-GS pinout, C8051F835-GS application, or C8051F835-GS equivalent, key selection criteria include CDC channel count and resolution, on-chip debug capability via C2 interface, Flash sector programming flexibility, wake-on-touch support, and QFN-20 package compatibility for space-constrained designs.

Technical Context

The C8051F835-GS implements a pipelined CIP-51 8051-compatible core with 70% of instructions executed in 1–2 system clocks, enabling deterministic real-time response for capacitive sensing and analog acquisition. Its CDC subsystem features auto-scan, programmable sample accumulation (4x–64x), and wake-on-touch - all managed independently of CPU execution.

Analog subsystem integration includes a 10-bit ADC with 500 ksps throughput, internal temperature sensor, and comparator with configurable hysteresis and interrupt/reset output. Clocking supports dynamic switching between internal 24.5 MHz ±2% oscillator and external sources, enabling low-power operation with crystal-less UART functionality.

Key Specifications

Pinout & Package

The C8051F835-GS is housed in a 20-pin QFN package (4×4 mm body, 0.5 mm lead pitch) with exposed thermal pad. Pin functions are defined per Figure 3.1 and Table 3.1 of Rev. 1.1 datasheet, supporting flexible peripheral routing via crossbar switch.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar capacitive-sensing MCU applications.

Compared with C8051F835-GS, C8051F830-GS offers reduced CDC capability and no on-die temperature sensor, while EFM8SB10F8G-A-QSOP24 delivers superior power efficiency and updated peripherals but requires firmware migration and lacks SMBus support - making C8051F835-GS optimal for existing designs needing full 16-channel CDC with thermal compensation and multi-protocol connectivity.

Availability

C8051F835-GS is available at Aetrix Electronics and suitable for home appliance control panels, industrial HMI terminals, medical device keypads, and interactive retail kiosks requiring stable component supply and long-lifecycle support.

Supply support for C8051F835-GS includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Silicon Laboratories is a fabless semiconductor company specializing in mixed-signal ICs for timing, IoT, and embedded control applications, with design centers in Austin, Munich, and Taipei.

The C8051F835-GS belongs to the C8051F80x-83x capacitive-sensing MCU family, engineered for cost-sensitive, space-constrained human interface applications requiring integrated analog sensing and robust 8051-based firmware execution.

FAQ

What is the maximum number of capacitive sense channels supported by the C8051F835-GS?

The C8051F835-GS supports up to 16 capacitive sense input channels via its integrated Capacitance-to-Digital Converter (CS0). These channels can be scanned automatically in sequence using the hardware auto-scan feature, and each supports programmable sample accumulation (4x–64x) to improve signal integrity. This capability is confirmed in Section 13 of the Rev. 1.1 datasheet and applies specifically to the C8051F835-GS variant.

Does the C8051F835-GS include an internal temperature sensor?

Yes, the C8051F835-GS includes a factory-calibrated internal temperature sensor with ±3°C accuracy across the –40 to +85 °C operating range. It is accessible via the ADC0 multiplexer and documented in Section 9 of the datasheet. This sensor is used for thermal drift compensation of the capacitive sense engine and system-level temperature monitoring - a feature present in the C8051F835-GS but omitted in lower-tier variants like C8051F830-GS.

What debug interface does the C8051F835-GS use, and is it compatible with standard tools?

The C8051F835-GS uses the two-wire C2 debug interface (C2CK and C2D pins), which is fully supported by Silicon Labs' Simplicity Studio IDE and third-party debug adapters such as the U-EC2 and CP210x-based programmers. This interface enables non-intrusive in-system debugging, flash programming, and real-time register/memory inspection - all without requiring an external emulator. The C2 protocol is standardized across the C8051F80x-83x family, including the C8051F835-GS.

Can the C8051F835-GS operate without an external crystal?

Yes, the C8051F835-GS can operate without an external crystal thanks to its built-in 24.5 MHz ±2% precision oscillator. This internal clock source supports full-speed operation (25 MIPS) and enables crystal-less UART communication - verified in Section 22.2 and Table 27.1 of the datasheet. External crystals remain optional for applications requiring tighter frequency tolerance or RTC accuracy, but are not required for basic C8051F835-GS functionality.

What package options are available for the C8051F835-GS, and which one is specified by the -GS suffix?

The C8051F835-GS is specified in the 20-pin QFN package (4×4 mm, 0.5 mm pitch) with exposed thermal pad, as indicated by the "-GS" suffix per Silicon Labs' ordering guide (Table 2.1). While the broader C8051F80x-83x family also includes QSOP-24 and SOIC-16 variants, the -GS suffix uniquely identifies the QFN-20 configuration - confirmed in Section 4 and Figure 3.1 of the Rev. 1.1 datasheet for the C8051F835-GS.