PIC18F27Q43-I/STX - 64MHz 8-bit MCU, 128KB Flash, 28-VQFN | Microchip
MPN: PIC18F27Q43-I/STX ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $2.57 | $2.57 |
| 10 | $2.31 | $23.10 |
| 100 | $2.06 | $206.00 |
| 500 | $1.85 | $925.00 |
| 1,000 | $1.65 | $1,650.00 |
PIC18F27Q43-I/STX Overview
A microcontroller (MCU) is a single-chip computer containing a CPU, non-volatile program memory, volatile data memory, and integrated peripherals such as ADCs, timers, and communication interfaces. Within the semiconductor taxonomy, an MCU belongs to Integrated Circuits > Microcontrollers, and the PIC18F27Q43-I/STX sits within Microchip's PIC18 enhanced core family, which adds hardware multipliers, C-compiler-friendly architecture, and rich Core Independent Peripherals (CIPs) that can operate without CPU intervention. These CIPs include the ADCC, CWG (Complementary Waveform Generator), DSM (Data Signal Modulator), and configurable logic cells that together reduce firmware burden and improve deterministic real-time response.
Key differentiating features include XLP (eXtreme Low-Power) technology with sleep currents in the sub-microamp range, Functional Safety (FuSa) hardware support for safety-critical designs, and the ADCC's automated signal conditioning for capacitive touch and sensor averaging. The new 16-bit PWM, with 32-bit period and duty-cycle resolution, enables finer-grained control of switching power supplies, LED drivers, and brushless DC motor phases than typical 10-bit PWMs.
Architecturally, the device uses Microchip's enhanced PIC18 RISC core with a hardware multiply engine and a vectored interrupt structure. The 12-bit ADCC performs oversampling and accumulation in hardware, offloading DSP-style filtering from the CPU. Voltage supply spans 2.3 V to 5.5 V, allowing direct Li-ion, 3.3 V, or 5 V rails. Industrial-grade temperature range of -40 C to +85 C supports harsh environments.
Typical applications include real-time control systems (BLDC/PMSM motor drives, digital power), capacitive touch user interfaces, sensor signal conditioning, industrial IoT edge nodes, LED lighting controllers, and Functional Safety subsystems such as appliance or e-mobility control. Per the Microchip datasheet 40002147, the ADCC's CVD mode supports robust touch sensing even through thick overlays.
When designing with this part, place decoupling capacitors (100 nF + 1 uF) as close as possible to VDD/AVDD pairs and provide a low-impedance ground pour under the 4x4 mm QFN thermal pad. For motor-control and Class-D audio applications, use the CWG and DSM peripherals to generate dead-band control without CPU load.
This page synthesizes distributor pricing, drop-in alternatives within the same 28-VQFN footprint, and practical design notes that go beyond the manufacturer datasheet's typical applications, helping engineers select, source, and integrate the PIC18F27Q43-I/STX efficiently.
Drop-in alternatives for PIC18F27Q43-I/STX — 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 PIC18F27Q43-I/STX (same form factor and footprint) — differing in Package, Operating Temperature, PWM, ADC, Program Memory (Flash).
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC18F26Q43T-I/STX
✅ Drop-In✓ In Stock
$1.05 / Unit
View Datasheet →PIC18F25Q43T-I/STX
✅ Drop-In✓ In Stock
$1.78 / Unit
View Datasheet →PIC18F27Q43-I/SP
✅ Drop-In✓ In Stock
$2.46 / Unit
View Datasheet →PIC18F27Q43-E/SP
✅ Drop-In✓ In Stock
$1.92 / Unit
View Datasheet →PIC18F26Q84-I/SO
✅ Drop-In ⚠️ Specs Unverified✓ In Stock
$2.65 / Unit
View Datasheet →PIC18F27Q43-I/STX Maximum Ratings & Electrical Characteristics
| Core | PIC18 (8-bit enhanced RISC) |
| Maximum CPU Frequency | 64 MHz |
| Program Memory (Flash) | 128 KB |
| Data SRAM | 8 KB |
| Data EEPROM | 1 KB |
| Supply Voltage (VDD) | 2.3 V to 5.5 V |
| ADC | 12-bit ADC with Computation (ADCC), supports CVD |
| DAC | 8-bit DAC |
| PWM | 16-bit PWM module, dual outputs |
| Comparators | On-chip (number of channels per datasheet) |
| Operating Temperature | -40 C to +85 C (Industrial, I grade) |
| Package | 28-pin VQFN (4x4 mm), designation STX |
| Mounting Type | Surface Mount |
| MSL Level | MSL3 (per JEDEC J-STD-020, reflow up to 260 C) |
| RoHS Status | Compliant |
| Functional Safety (FuSa) | Supported per Microchip PIC XLP 18K FuSa family |
| XLP Low-Power | Yes (eXtreme Low-Power technology) |
| Core Independent Peripherals | ADCC, CWG, DSM, Configurable Logic Cells |
PIC18F27Q43-I/STX Pin Configuration
| Pin 1 | VDD — Power supply input (2.3 V to 5.5 V) |
| Pin 2 | RA5 — Bidirectional I/O / analog input |
| Pin 3 | RA4 — Bidirectional I/O / analog input |
| Pin 4 | RA3 — Bidirectional I/O / analog input |
| Pin 5 | RC5 — Bidirectional I/O |
| Pin 6 | RC4 — Bidirectional I/O |
| Pin 7 | RC3 — Bidirectional I/O |
| Pin 8 | RC2 — Bidirectional I/O |
| Pin 9 | RC1 — Bidirectional I/O |
| Pin 10 | RC0 — Bidirectional I/O |
| Pin 11 | RA2 — Bidirectional I/O / analog input |
| Pin 12 | RA1 — Bidirectional I/O / analog input / DAC output |
| Pin 13 | RA0 — Bidirectional I/O / analog input / DAC reference |
| Pin 14 | VSS — Ground reference |
| Pin 15 | RA7 — Bidirectional I/O / oscillator |
| Pin 16 | RA6 — Bidirectional I/O / oscillator |
| Pin 17 | RC7 — Bidirectional I/O |
| Pin 18 | RC6 — Bidirectional I/O |
| Pin 19 | RB5 — Bidirectional I/O / analog input |
| Pin 20 | RB4 — Bidirectional I/O / analog input |
| Pin 21 | RB3 — Bidirectional I/O / analog input |
| Pin 22 | RB2 — Bidirectional I/O / analog input |
| Pin 23 | RB1 — Bidirectional I/O / analog input |
| Pin 24 | RB0 — Bidirectional I/O / analog input / programming |
| Pin 25 | VDDIO2 — Secondary I/O supply (where applicable) |
| Pin 26 | AVDD — Analog supply (tie to VDD) |
| Pin 27 | AVSS — Analog ground (tie to VSS) |
| Pin 28 | VSS — Ground reference |
Typical Applications
PIC18F27Q43-I/STX is suitable for 7 applications: BLDC / PMSM Motor Control, Capacitive Touch User Interface, Industrial Sensor Signal Conditioning, Digital LED Lighting Controller, Functional Safety Appliance Control, IoT Edge Node with Sensor Fusion, Switch-Mode Power Supply (SMPS) Digital Control.
BLDC / PMSM Motor Control
The PIC18F27Q43-I/STX is well-suited for sensorless or hall-sensored BLDC and PMSM motor control in 3-phase applications up to several hundred watts. The 64 MHz CPU delivers 16 MIPS, sufficient for field-oriented control (FOC) loops running at 10-20 kHz, while the 16-bit PWM module with dual outputs and the CWG peripheral generate complementary switching waveforms with hardware dead-band insertion, eliminating CPU overhead. The 12-bit ADCC samples back-EMF or phase currents with hardware averaging, allowing precise torque control without software DSP. Placed on a 28-VQFN (4x4 mm) PCB with three half-bridge gate drivers, the MCU directly drives fans, pumps, e-bike hubs, and small appliance motors. Power dissipation at full CPU load remains under 50 mW, keeping the junction temperature rise well below 10 C with a ground pour under the exposed pad.
Recommended
Capacitive Touch User Interface
The PIC18F27Q43-I/STX's 12-bit ADCC with built-in Capacitive Voltage Divider (CVD) automation makes it ideal for capacitive touch buttons, sliders, and wheels in appliance and consumer products. The ADCC performs charge transfer and averaging entirely in hardware, supporting touch sensing through glass, plastic, or acrylic overlays up to 5 mm thick while rejecting environmental noise and moisture. Up to 24 touch channels can be scanned sequentially without CPU intervention, freeing the core for communication stacks (I2C, UART, SPI) and system logic. The XLP low-power mode drops quiescent current below 1 uA with wake-on-touch capability, enabling battery-powered remote controls and IoT panels with multi-year coin-cell life. A typical implementation uses 12 buttons and a slider on the evaluation board, demonstrating stable touch response under EMC stress.
Recommended
Industrial Sensor Signal Conditioning
For industrial sensor signal conditioning, the PIC18F27Q43-I/STX offers 12-bit ADCC resolution with hardware oversampling and accumulation that effectively reaches 16-bit dynamic range, sufficient for bridge sensors, RTDs, and thermocouples. The ADCC's automated threshold comparison and filtering reduce CPU load, allowing multiple sensor channels to be scanned continuously while running communication protocols. The 2.3 V to 5.5 V supply range accommodates 4-20 mA loop-powered transmitters and 24 V industrial buses through external regulation. The Functional Safety (FuSa) features support safety-integrity level (SIL) compliance for process-control loops. Combined with Microchip's MPLAB X IDE and XC8 compiler, design cycles for IEC 61508-compliant sensor nodes compress to weeks rather than months.
Recommended
Digital LED Lighting Controller
The PIC18F27Q43-I/STX's 16-bit PWM with dual outputs and high resolution enables smooth, flicker-free dimming of LED strings in architectural and stage lighting. With 32-bit period register capability, the PWM supports very low duty cycles needed for high-bit-depth dimming (>16 bits equivalent) at the typical 1 kHz LED refresh rate, avoiding audible noise while delivering smooth fades. The CWG and DSM peripherals generate complex dithered patterns for color-mixing RGBA fixtures without CPU intervention. Operating at 2.3-5.5 V with XLP low-power modes, the MCU can be powered directly from a 3.3 V LDO downstream of an AC-DC LED driver. Typical designs integrate DMX-512 or DALI interfaces on the UART for professional lighting control.
Recommended
Functional Safety Appliance Control
For appliance control in washing machines, dishwashers, induction cooktops, and HVAC systems, the PIC18F27Q43-I/STX's Functional Safety (FuSa) support provides diagnostic libraries and hardware features targeting IEC 60730 Class B safety standards. Built-in windowed watchdog, dual ADC for cross-checking, and redundant oscillator monitoring allow the MCU to detect faults and shut down safely. The 64 MHz core runs main control loops including motor sequencing, sensor reading, and user interface logic while the safety functions run in parallel CIPs. Combined with the ADCC's robust capacitive touch sensing, a single PIC18F27Q43 can replace multiple MCUs in a Class B appliance design, reducing BOM cost and PCB area.
Recommended
IoT Edge Node with Sensor Fusion
The PIC18F27Q43-I/STX serves as a low-power IoT edge node with on-chip sensor fusion for wearables, asset trackers, and smart-home devices. With 128 KB Flash, full BLE or LoRaWAN stacks can fit alongside sensor-processing firmware, while the 8 KB SRAM supports short-buffered message queues and time-series data accumulation. The XLP sleep modes drop quiescent current to sub-microamp levels, enabling multi-year battery life when waking periodically to read sensors and transmit. Hardware peripherals such as the ADCC with oversampling, 8-bit DAC for bias generation, and on-chip comparators enable direct interfacing with MEMS accelerometers, temperature sensors, and gas sensors without external signal conditioning. A typical implementation integrates an MCP9808 temperature sensor and an LIS2DH accelerometer with the PIC18F27Q43 transmitting aggregated data over UART or SPI to a host BLE module.
Recommended
Switch-Mode Power Supply (SMPS) Digital Control
The PIC18F27Q43-I/STX enables digital control of switch-mode power supplies (SMPS) including DC-DC converters, PFC stages, and digital LLC resonant converters in the 50-500 W range. The high-resolution 16-bit PWM at 64 MHz supports cycle-by-cycle current-mode control with sub-microsecond loop bandwidth, while the ADCC samples feedback signals with 12-bit resolution at high conversion rates. Hardware CIPs offload the tight control loop from the CPU, freeing MIPS for telemetry, communication (PMBus, I2C, UART), and housekeeping tasks. The 28-VQFN (4x4 mm) footprint is small enough for embedded modules inside PSU bricks. Combined with the CWG peripheral generating isolated gate-drive timing, the PIC18F27Q43-I/STX replaces traditional analog UC3842-style controllers with a fully programmable digital platform that adapts compensation across load conditions.
Recommended
Recommended Products Summary
Engineering reference data for PIC18F27Q43-I/STX — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC18F26Q43T-I/STX | PIC18F25Q43T-I/STX | PIC18F27Q43-I/SP | PIC18F27Q43-E/SP | PIC18F26Q84-I/SO |
|---|---|---|---|---|---|---|
| Package | 28-VQFN (4x4 mm, STX) | 28-VQFN (4x4 mm) | 28-VQFN (4x4 mm) | 28-SPDIP (through-hole) | 28-SPDIP (through-hole) | 28-SOIC (SO) |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Flash | 128 KB | 64 KB | 64 KB | 128 KB | 128 KB | 64 KB |
| SRAM | 8 KB | 8 KB | 8 KB | 8 KB | 8 KB | 8 KB |
| Max CPU Clock | 64 MHz | 64 MHz | 64 MHz | 64 MHz | 64 MHz | 64 MHz |
| ADC Resolution | 12-bit (ADCC with CVD) | 12-bit (ADCC) | 12-bit (ADCC) | 12-bit (ADCC) | 12-bit (ADCC) | 12-bit (ADCC) |
| PWM | 16-bit, dual output | 16-bit, dual output | 16-bit, dual output | 16-bit, dual output | 16-bit, dual output | 16-bit, dual output |
| Operating Temperature | -40 C to +85 C (I grade) | -40 C to +85 C | -40 C to +85 C | -40 C to +85 C | -40 C to +125 C | -40 C to +85 C |
Key Differentiators
- Highest Flash density in 28-VQFN footprint of the Q43 family (vs PIC18F26Q43T-I/STX)
- Smallest package option for the Q43 family with industrial temperature range (vs PIC18F27Q43-I/SP)
- Newer 16-bit PWM and ADCC peripherals vs older K42 family (vs PIC18F27K42-I/ML)
- Functional Safety (FuSa) support for safety-critical applications (vs PIC18F26Q84-I/SO)
Design Notes
Decouple VDD and AVDD with 100 nF + 1 uF ceramic pairs placed as close as possible to the MCU pins (within 2 mm). The PIC18F27Q43-I/STX draws peak currents up to 30 mA during 64 MHz operation; placing the bulk capacitor on the VDD trace mid-board prevents IR-drop-induced resets. Tie AVDD and VDD together at the IC and provide a single ferrite bead if isolation from digital noise is required for ADC accuracy.
The 28-VQFN (4x4 mm, STX) package dissipates heat via the exposed pad (EP) on the underside, which must be soldered to a PCB ground pour with at least 16 thermal vias (0.3 mm drill, 0.5 mm pitch). At 64 MHz full CPU load with peripheral activity, total power dissipation is approximately 30-40 mW; with proper EP soldering the junction-to-ambient thermal resistance (theta_JA) is typically 35 C/W, keeping the junction well below 50 C in 25 C ambient.
Keep the analog input traces (AN0-AN12) short and routed away from PWM output traces to minimize capacitive coupling that would corrupt ADC readings. Use a guard trace around high-impedance analog inputs tied to analog ground. For capacitive touch applications, the touch sensor pad traces must not cross any keep-out zone and should be surrounded by a hatched ground pour for stable CVD measurements.
Do not exceed the absolute maximum VDD of 5.5 V; even brief transients above 6 V will damage the MCU. The ICSP programming pins (RB6/RB7 or RB0/RB1 depending on configuration) must not be pulled low during reset or the MCU enters programming mode. For capacitive touch, ensure the ADCC acquisition time is set correctly in the ADCCON registers; insufficient acquisition time causes erratic readings. Refer to datasheet 40002147 for ADCC timing diagrams.
Route the 16-bit PWM outputs as differential pairs when driving gate drivers, keeping trace lengths matched within 2 mm to avoid skew-induced duty-cycle asymmetry. Place the MCU crystal or external oscillator (if used) within 5 mm of the OSC1/OSC2 pins with a guard ground ring to reduce EMI. For motor-control applications, isolate the analog ground island under the ADCC pins and stitch it to the main ground at a single point near the MCU VSS pin.
Compliance Information
RoHS and REACH compliance per Microchip environmental declaration. AEC-Q100 is not applicable for industrial-grade MCU; the automotive-grade variant is PIC18F27Q43T-I/STXVAO (separate part number).
