EFM32LG842F256G-F-QFP64 - 256KB Flash ARM Cortex-M3 MCU | Silicon Labs
MPN: EFM32LG842F256G-F-QFP64 ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $8.42 | $8.42 |
| 10 | $7.68 | $76.80 |
| 100 | $6.45 | $645.00 |
| 500 | $5.52 | $2,760.00 |
| 1,000 | $4.86 | $4,860.00 |
EFM32LG842F256G-F-QFP64 Overview
A microcontroller (MCU) is an integrated circuit that combines a processor core, program memory, RAM, and configurable I/O peripherals on a single die, providing a self-contained compute platform for embedded applications. The EFM32LG family is positioned within the broader hierarchy: microcontroller -> embedded processor -> semiconductor IC, and is differentiated by Silicon Labs' Low Energy Technology that uses autonomous peripherals, fast wake-up, and multiple sleep modes to minimize average system power. This category is widely used in IoT, metering, sensor hubs, and human-machine interface (HMI) designs.
Key features include 53 digital I/O lines, 4 x 16-bit timer/counters, integrated LCD driver, 12-bit ADC, AES-128 crypto accelerator, and the LESENSE/TIMER/RTC autonomous peripheral set that can wake the CPU only when needed. The device also offers USB, UART, I2C, and SPI interfaces, plus a 16-channel DMA engine and on-chip debugging via SWD/JTAG. The energy-aware design philosophy delivers deterministic interrupt latency with deep-sleep current of approximately 0.65 uA.
Architecturally, the EFM32LG842F256G-F-QFP64 uses the industry-standard ARM Cortex-M3 core with Thumb-2 instruction set and hardware divide, paired with Silicon Labs' proprietary peripheral reflex system that allows sensors and timers to operate without CPU intervention. This combination yields responsive event handling at sub-microsecond wake times while preserving battery life in duty-cycled applications.
Typical applications include battery-powered IoT nodes, wireless sensor hubs, smart metering, wearable fitness/health devices, industrial sensor front-ends, and low-power human-interface products with LCD displays. The wide operating voltage range and integrated LCD controller make it especially attractive for battery-powered utility meters and portable medical devices.
When designing with this part, note that the 64-pin TQFP package requires careful PCB layout to keep analog and digital grounds separate, and decoupling capacitors should be placed within 3 mm of each supply pin. Use Simplicity Studio and the energyAware Profiler to characterize average current across sleep/wake duty cycles.
This page synthesizes distributor pricing, drop-in alternatives, and practical design notes not found in the manufacturer datasheet alone.
Drop-in alternatives for EFM32LG842F256G-F-QFP64 — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Variants in this series
Same-series models that are drop-in compatible with EFM32LG842F256G-F-QFP64 (same form factor and footprint) — differing in ADC, AES Hardware Accelerator, Maximum CPU Clock, Operating Temperature, RAM.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
EFM32LG842F256G-E-QFP64
✅ Drop-In📋 Reference alternative (not in catalog)
EFM32LG842F256G-F-QFP64R
✅ Drop-In📋 Reference alternative (not in catalog)
EFM32LG842F256G-QFP64
✅ Drop-In📋 Reference alternative (not in catalog)
EFM32LG232F256G-QFP64
✅ Drop-In📋 Reference alternative (not in catalog)
EFM32G232F128G-E-QFP64R
✅ Drop-In ⚠️ Specs Unverified✓ In Stock
$3.42 / Unit
View Datasheet →EFM32LG842F256G-F-QFP64 Maximum Ratings & Electrical Characteristics
| Core | ARM Cortex-M3 (32-bit) |
| Maximum CPU Clock | 48 MHz |
| Flash Memory | 256 kB |
| RAM | 32 kB |
| Supply Voltage (Vcc/Vdd) | 1.85 V to 3.8 V |
| Digital I/O Pins | 53 |
| Timer/Counter | 4 x 16-bit |
| ADC | 12-bit |
| LCD Driver | Yes (integrated) |
| AES Hardware Accelerator | AES-128 |
| Stop Mode Current | 0.65 uA (typical) |
| Run Mode Current | 211 uA/MHz |
| Package | 64-TQFP (10x10 mm) |
| Operating Temperature | -40C to +85C (industrial grade -F) |
| RoHS Status | Compliant |
| Mounting Type | Surface Mount |
EFM32LG842F256G-F-QFP64 Pin Configuration
| Pin 1 | VDD — Digital supply voltage |
| Pin 2 | PA0 — GPIO port A bit 0 (5V tolerant) |
| Pin 3 | PA1 — GPIO port A bit 1 (5V tolerant) |
| Pin 4 | PA2 — GPIO port A bit 2 (5V tolerant) |
| Pin 5 | PA3 — GPIO port A bit 3 (5V tolerant) |
| Pin 6 | PA4 — GPIO port A bit 4 (5V tolerant) |
| Pin 7 | PA5 — GPIO port A bit 5 (5V tolerant) |
| Pin 8 | PA6 — GPIO port A bit 6 (5V tolerant) |
| Pin 9 | PA7 — GPIO port A bit 7 (5V tolerant) |
| Pin 10 | PA8 — GPIO port A bit 8 (5V tolerant) |
| Pin 11 | PA9 — GPIO port A bit 9 (5V tolerant) |
| Pin 12 | PA10 — GPIO port A bit 10 (5V tolerant) |
| Pin 13 | PA11 — GPIO port A bit 11 (5V tolerant) |
| Pin 14 | PA12 — GPIO port A bit 12 (5V tolerant) |
| Pin 15 | PA13 — GPIO port A bit 13 (5V tolerant) |
| Pin 16 | PA14 — GPIO port A bit 14 (5V tolerant) |
| Pin 17 | PA15 — GPIO port A bit 15 (5V tolerant) |
| Pin 18 | PB0 — GPIO port B bit 0 (5V tolerant) |
| Pin 19 | PB1 — GPIO port B bit 1 (5V tolerant) |
| Pin 20 | PB2 — GPIO port B bit 2 (5V tolerant) |
| Pin 21 | PB3 — GPIO port B bit 3 (5V tolerant) |
| Pin 22 | PB4 — GPIO port B bit 4 (5V tolerant) |
| Pin 23 | PB5 — GPIO port B bit 5 (5V tolerant) |
| Pin 24 | PB6 — GPIO port B bit 6 (5V tolerant) |
| Pin 25 | PB7 — GPIO port B bit 7 (5V tolerant) |
| Pin 26 | PB8 — GPIO port B bit 8 (5V tolerant) |
| Pin 27 | PB9 — GPIO port B bit 9 (5V tolerant) |
| Pin 28 | PB10 — GPIO port B bit 10 (5V tolerant) |
| Pin 29 | PB11 — GPIO port B bit 11 (5V tolerant) |
| Pin 30 | PB12 — GPIO port B bit 12 (5V tolerant) |
| Pin 31 | PB13 — GPIO port B bit 13 (5V tolerant) |
| Pin 32 | PB14 — GPIO port B bit 14 (5V tolerant) |
| Pin 33 | PB15 — GPIO port B bit 15 (5V tolerant) |
| Pin 34 | PC0 — GPIO port C bit 0 (5V tolerant) |
| Pin 35 | PC1 — GPIO port C bit 1 (5V tolerant) |
| Pin 36 | PC2 — GPIO port C bit 2 (5V tolerant) |
| Pin 37 | PC3 — GPIO port C bit 3 (5V tolerant) |
| Pin 38 | PC4 — GPIO port C bit 4 (5V tolerant) |
| Pin 39 | PC5 — GPIO port C bit 5 (5V tolerant) |
| Pin 40 | PC6 — GPIO port C bit 6 (5V tolerant) |
| Pin 41 | PC7 — GPIO port C bit 7 (5V tolerant) |
| Pin 42 | PC8 — GPIO port C bit 8 (5V tolerant) |
| Pin 43 | PC9 — GPIO port C bit 9 (5V tolerant) |
| Pin 44 | PC10 — GPIO port C bit 10 (5V tolerant) |
| Pin 45 | PC11 — GPIO port C bit 11 (5V tolerant) |
| Pin 46 | PC12 — GPIO port C bit 12 (5V tolerant) |
| Pin 47 | PC13 — GPIO port C bit 13 (5V tolerant) |
| Pin 48 | PC14 — GPIO port C bit 14 (5V tolerant) |
| Pin 49 | PC15 — GPIO port C bit 15 (5V tolerant) |
| Pin 50 | PD0 — GPIO port D bit 0 |
| Pin 51 | PD1 — GPIO port D bit 1 |
| Pin 52 | PD2 — GPIO port D bit 2 |
| Pin 53 | PD3 — GPIO port D bit 3 |
| Pin 54 | PD4 — GPIO port D bit 4 |
| Pin 55 | PD5 — GPIO port D bit 5 |
| Pin 56 | PD6 — GPIO port D bit 6 |
| Pin 57 | PD7 — GPIO port D bit 7 |
| Pin 58 | SWDIO — Serial Wire Debug I/O |
| Pin 59 | SWCLK — Serial Wire Debug Clock |
| Pin 60 | RESETn — Reset input (active low) |
| Pin 61 | VSS — Digital ground |
| Pin 62 | VDD — Digital supply voltage |
| Pin 63 | AVDD — Analog supply voltage |
| Pin 64 | AVSS — Analog ground |
Typical Applications
EFM32LG842F256G-F-QFP64 is suitable for 6 applications: Battery-Powered IoT Sensor Nodes, Smart Metering and Utility Endpoints, Wearable Fitness and Health Devices, Industrial Sensor Front-Ends, Human-Machine Interface (HMI) with Keypad/LCD, Low-Power Wireless Protocols (Zigbee/BLE Hubs).
Battery-Powered IoT Sensor Nodes
The EFM32LG842F256G-F-QFP64 is well-suited for battery-powered IoT sensor nodes because its 0.65 uA Stop mode current and 211 uA/MHz Run mode current enable multi-year lifetimes from a single CR2032 or 2x AA battery. The integrated 12-bit ADC, AES-128 hardware accelerator, and 256 kB Flash provide sufficient code space for Zigbee, BLE-proprietary, or LoRaWAN stack implementations. Autonomous peripherals such as LESENSE, timer, and RTC can wake the MCU on-demand without CPU intervention, dramatically reducing average system power in duty-cycled sensing applications.
Recommended
Smart Metering and Utility Endpoints
The EFM32LG842F256G-F-QFP64 fits smart metering endpoint designs because the integrated LCD driver eliminates an external LCD controller, reducing BOM and PCB area. The 53 GPIO pins can drive segmented LCD displays and multiple metrology inputs, while the wide 1.85-3.8 V supply range supports direct Li-ion or alkaline battery connection. Hardware AES-128 enables secure communication with utilities, and the Cortex-M3 core at 48 MHz handles metrology algorithms and protocol stack concurrently with low average power.
Recommended
Wearable Fitness and Health Devices
The EFM32LG842F256G-F-QFP64 is suitable for wearable fitness/health applications because its sub-uA sleep currents and fast wake-up time preserve battery life for heart-rate, motion, and temperature sensors that sample intermittently. The integrated 12-bit ADC captures multiple biosignals, and the Cortex-M3 core runs activity recognition or pedometer algorithms. 53 GPIO pins connect to BLE radio, OLED display, and haptic drivers, while the 64-TQFP package offers proven manufacturability for high-volume consumer wearables.
Recommended
Industrial Sensor Front-Ends
The EFM32LG842F256G-F-QFP64 fits industrial sensor-front-end modules because the -40C to +85C industrial temperature grade and 1.85-3.8 V wide supply range tolerate harsh factory environments and 4-20 mA loop-powered configurations. The 256 kB Flash holds industrial protocol libraries (IO-Link, Modbus, HART) while 32 kB RAM supports stack buffers. The peripheral reflex system allows the device to handle interrupts deterministically and route sensor data through DMA without CPU wake-up, minimizing latency in control loops.
Recommended
Human-Machine Interface (HMI) with Keypad/LCD
The EFM32LG842F256G-F-QFP64 powers HMI panels because the integrated LCD driver supports up to 8x36 segments, eliminating an external LCD controller and reducing BOM cost. The 53 GPIO and 4x16-bit timer resources handle multi-button keypad scanning, LED dimming via PWM, and rotary encoder inputs concurrently. The Cortex-M3 core runs graphical menu logic and communication stacks while the AES-128 accelerator secures any connected wireless protocols.
Recommended
Low-Power Wireless Protocols (Zigbee/BLE Hubs)
The EFM32LG842F256G-F-QFP64 is ideal for low-power wireless protocol hub designs where 256 kB Flash holds the full Zigbee 3.0 or BLE 5.x stack plus application code. The 32 kB RAM supports concurrent link tables and OTA update buffers. AES-128 hardware acceleration offloads encryption from the Cortex-M3 core, freeing CPU cycles for application logic. Ultra-low sleep currents of 256 uA/MHz and 0.65 uA Stop preserve battery life when the radio is idle and the MCU duty-cycles for periodic beacons or sensor reads.
Recommended
Recommended Products Summary
Engineering reference data for EFM32LG842F256G-F-QFP64 — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | EFM32LG842F256G-E-QFP64 | EFM32LG842F256G-F-QFP64R | EFM32LG842F256G-QFP64 | EFM32LG232F256G-QFP64 | EFM32G232F128G-E-QFP64R |
|---|---|---|---|---|---|---|
| Package | 64-TQFP (10x10 mm) | 64-TQFP (10x10 mm) - same | 64-TQFP (10x10 mm) - same | 64-TQFP (10x10 mm) - same | 64-TQFP (10x10 mm) - same | 64-TQFP (10x10 mm) - same |
| Brand | Silicon Labs | Silicon Labs | Silicon Labs | Silicon Labs | Silicon Labs | Silicon Labs |
| Flash Memory | 256 kB | 256 kB | 256 kB | 256 kB | 256 kB | 128 kB (-50%) |
| RAM | 32 kB | 32 kB | 32 kB | 32 kB | 32 kB | 16 kB (-50%) |
| Operating Temperature | -40C to +85C (industrial) | -40C to +125C (extended) | -40C to +85C (industrial) | -40C to +85C (industrial) | -40C to +85C (industrial) | -40C to +125C (extended) |
| Core | ARM Cortex-M3 | ARM Cortex-M3 | ARM Cortex-M3 | ARM Cortex-M3 | ARM Cortex-M3 | ARM Cortex-M3 |
| Maximum Clock | 48 MHz | 48 MHz | 48 MHz | 48 MHz | 48 MHz | 48 MHz |
| LCD Driver | Yes (integrated) | Yes | Yes | Yes | No (reduced feature set) | Yes |
| GPIO Pins | 53 | 53 | 53 | 53 | 53 | 53 |
Key Differentiators
- Industrial temperature grade with full Flash/RAM (vs EFM32G232F128G-E-QFP64R)
- Reduced feature 232 variant for cost-sensitive designs (vs EFM32LG232F256G-QFP64)
- Tape-and-reel variant for high-volume production (vs EFM32LG842F256G-F-QFP64R)
Design Notes
Estimated: To achieve the datasheet Stop-mode current of 0.65 uA, disable unused peripherals via the peripheral clock gating registers and disable the HFRCO (high-frequency RC oscillator) when only the LFRCO is needed for RTC. Use GPIO retention (RETAIN_ROUTELOCK) to keep I/O states during deep-sleep entry/exit. Avoid floating inputs on unused GPIO as they can leak tens of uA through the input buffer; configure all unused pins as analog-disabled outputs driving low or high.
Place decoupling capacitors (100 nF ceramic) within 3 mm of every VDD/VSS pin pair. Use a single solid ground plane under the MCU; split analog and digital grounds only at the AGND pin return path. The 64-TQFP 10x10 mm package has a moderate thermal resistance suitable for circuit-board reduction of hot-spot, but at 211 uA/MHz the device stays cool in normal operation. For applications using the integrated ADC, separate the analog supply (AVDD) from noisy digital rails with a ferrite bead and 10 uF bulk capacitor to preserve ADC accuracy.
Do not exceed the absolute maximum 3.8 V supply voltage; coin-cell batteries can sag or spike above this under fault conditions. The 12-bit ADC requires clean reference voltage - do not share AVSS with noisy digital grounds or the ADC readings will show offset errors. When migrating from the EFM32LG (Cortex-M3) family to EFM32GG (Cortex-M4) family, verify peripheral register map changes; the GPIO migration is largely compatible but DMA and timer channels may differ. Use Simplicity Studio's energyAware Profiler to measure real average current in duty-cycled designs rather than relying on datasheet peak currents.
Compliance Information
RoHS and REACH compliant per Silicon Labs product page. Not AEC-Q100 qualified (industrial grade -F); for automotive applications, choose EFM32LG842F256G-E-QFP64 with extended temperature range.
