Silicon Labs C8051F332-GMR

Overview

C8051F332-GMR from Silicon Laboratories is a mixed-signal ISP Flash MCU featuring an 8051-compatible CIP-51 core delivering 25 MIPS at 25 MHz, 4 kB flash memory, 768 B SRAM, and integrated 10-bit ADC (200 ksps, 16-channel), voltage comparator, and hardware UART/SMBus/SPI serial interfaces - deployed in low-power sensor interface and industrial control nodes.

For engineers reviewing the C8051F332-GMR datasheet, C8051F332-GMR pinout, C8051F332-GMR application, or C8051F332-GMR equivalent, key selection criteria include its 20-pin QFN package, 2.7–3.6 V supply range, sub-µA stop-mode current (0.1 µA), on-chip debug via C2 interface, and analog-peripheral integration for embedded measurement systems requiring minimal external components.

Technical Context

The C8051F332-GMR implements a pipelined 8051 core (CIP-51) executing 70% of instructions in 1–2 system clocks, with dual internal oscillators: a 24.5 MHz ±2% precision oscillator enabling crystal-less UART operation and an 80/40/20/10 kHz low-power oscillator for sleep-mode timing. Its analog subsystem includes a 10-bit ADC with programmable input mux, internal temperature sensor, and reference selection (VREF pin, internal VREF, or VDD).

Digital peripherals are routed through a flexible crossbar switch to 17 GPIO pins (all 5 V tolerant), supporting hardware UART, SMBus, and enhanced SPI. Power management includes Idle and Stop modes, with typical stop current of 0.1 µA and wake-up capability from comparator, PCA, or external interrupt sources.

Key Specifications

Pinout & Package

20-pin QFN package (4 × 4 mm body, 0.5 mm pitch, exposed thermal pad). Pin assignments are validated per Silicon Labs' Rev. 1.7 datasheet Table 4.1 and Figure 4.1.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar mixed-signal MCU applications.

Compared with C8051F330-GMR and C8051F331-GMR, the C8051F332-GMR provides the optimal trade-off: sufficient 4 kB flash for compact firmware, full analog sensing capability (10-bit ADC, temp sensor, comparator), and no redundant DAC - making it ideal for cost-sensitive, sensor-rich embedded designs where analog integration reduces component count.

Availability

C8051F332-GMR is available at Aetrix Electronics and suitable for industrial sensor nodes, smart building controllers, and portable instrumentation requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for C8051F332-GMR 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 C8051F33x family was engineered for cost-sensitive, low-power embedded systems requiring integrated analog peripherals and robust in-system debug - targeting sensor fusion, industrial automation, and consumer electronics.

FAQ

What is the maximum ADC sampling rate supported by the C8051F332-GMR?

The C8051F332-GMR supports a maximum ADC conversion rate of 200 ksps (kilo-samples per second) in its 10-bit successive approximation register (SAR) architecture. This rate applies when using the internal 24.5 MHz system clock and optimized tracking/conversion timing. Real-world sustained throughput depends on channel count, reference settling, and software overhead - typically achieving ~150 ksps in multi-channel polled mode. The C8051F332-GMR ADC includes built-in temperature sensor and programmable window compare for autonomous threshold detection.

Does the C8051F332-GMR include an internal voltage reference for the ADC?

Yes, the C8051F332-GMR includes an internal 2.4 V voltage reference that can be selected as the ADC reference source via configuration registers. It also supports external reference input on the VREF pin or direct use of VDD as reference. The internal reference is factory-calibrated and stable across temperature and supply voltage, enabling consistent 10-bit ADC measurements without external reference ICs. This capability is confirmed in the "Voltage Reference" section (page 61) of the C8051F330/1/2/3/4/5 Rev. 1.7 datasheet.

Can the C8051F332-GMR operate without an external crystal?

Yes, the C8051F332-GMR can operate fully without an external crystal thanks to its dual internal oscillators: a 24.5 MHz high-frequency oscillator with ±2% accuracy and an 80/40/20/10 kHz low-frequency oscillator. The 24.5 MHz oscillator supports crystal-less UART operation with baud rate error under 2%, eliminating the need for external timing components in many applications. System clock source can be switched dynamically between internal and external options, enabling flexible power management strategies in the C8051F332-GMR.

What debug interface does the C8051F332-GMR use, and how many pins are required?

The C8051F332-GMR uses the C2 two-wire debug interface, requiring only two dedicated pins: C2D (P0.0) for bidirectional data and C2CK (P0.1) for clock. This interface enables full-speed, non-intrusive in-system debugging - including breakpoints, single-stepping, and memory/register inspection - without emulator hardware or target socket. The C2 interface is electrically compatible with standard 3.3 V logic levels and supports both development and production programming of the C8051F332-GMR.

Is the C8051F332-GMR pin-compatible with other devices in the C8051F33x family?

Yes, the C8051F332-GMR is pin-compatible with all members of the C8051F33x family (C8051F330/1/2/3/4/5) in the 20-pin QFN package, sharing identical pin definitions and electrical characteristics per Table 4.1 of the Rev. 1.7 datasheet. However, functional differences exist: only C8051F330/2/4 include the 10-bit ADC; only C8051F330 includes the 10-bit current DAC; and flash sizes vary (8/4/2 kB). PCBs designed for C8051F332-GMR can accommodate C8051F330-GMR or C8051F331-GMR without layout changes, but firmware must match the specific peripheral set of the installed C8051F332-GMR.