PIC18F27Q43-I/SO - 128KB Flash 8-bit MCU, 28-SOIC | Microchip
MPN: PIC18F27Q43-I/SO ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $3.42 | $3.42 |
| 10 | $3.08 | $30.80 |
| 100 | $2.62 | $262.00 |
| 500 | $2.31 | $1,155.00 |
| 1,000 | $2.05 | $2,050.00 |
| 3,000 | $1.85 | $5,550.00 |
PIC18F27Q43-I/SO Overview
An 8-bit microcontroller (MCU) is a single-chip computer that combines a CPU, program memory (Flash), data memory (RAM), and peripherals on a single silicon die. The PIC18 architecture is Harvard-organized with separate program and data buses, and the PIC18F27Q43 belongs to the PIC18-Q43 family which combines Microchip's most popular Core Independent Peripherals (CIPs) with advanced signal routing. This category of MCU sits in the broader hierarchy: microcontroller -> embedded processor -> semiconductor IC, and is typically used where deterministic real-time response, low power, and rich analog integration are required.
Key differentiating features include six DMA controllers that move data without CPU intervention, hardware 16-bit PWM with independent time bases, the ADCC that automates averaging and oversampling, and 10-bit slope compensation for power-conversion loops. The functional safety (FuSa) documentation and built-in diagnostics make the part attractive for safety-related industrial and appliance designs. With XLP (eXtreme Low Power) technology and the ability to wake from sleep on peripheral triggers, the device fits battery-powered and energy-harvesting applications.
Typical applications include industrial real-time control (BLDC motor drives, power conversion), capacitive touch user interfaces for appliances and consumer products, lighting controls, IoT sensor nodes, and USB-to-UART bridges when paired with the on-chip USB 2.0 FS peripheral. The 28-pin SOIC footprint offers generous analog channels and PWM outputs in a through-hole-friendly SMD package that supports hand-prototyping as well as high-volume SMT assembly.
Drop-in alternatives for PIC18F27Q43-I/SO — 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/SO (same form factor and footprint) — differing in Package, Core Architecture, Program Memory (Flash), Mounting Type, ADC Resolution.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC18F27Q43-I/SP
✅ Drop-In✓ In Stock
$2.46 / Unit
View Datasheet →PIC18F27Q43-E/SO
✅ Drop-In📋 Reference alternative (not in catalog)
PIC18F27Q43-I/SS
✅ Drop-In📋 Reference alternative (not in catalog)
PIC18F27K42-I/SO
✅ Drop-In✓ In Stock
$1.95 / Unit
View Datasheet →PIC18F26Q43-I/SO
✅ Drop-In📋 Reference alternative (not in catalog)
PIC18F25Q43-I/SO
✅ Drop-In✓ In Stock
$1.21 / Unit
View Datasheet →PIC18F27Q43-I/SO Maximum Ratings & Electrical Characteristics
| Architecture | PIC18 8-bit Harvard |
| Core | PIC18 enhanced RISC |
| Maximum CPU Frequency | 64 MHz |
| Program Memory (Flash) | 128 KB |
| Data Memory (RAM) | 8 KB |
| EEPROM | 1 KB |
| Operating Voltage Range | 1.8 V to 5.5 V |
| I/O Pins | 21 (on 28-pin SOIC) |
| ADC | 12-bit ADC with Computation (ADCC) |
| DAC | Two 8-bit DAC outputs |
| PWM | Three 16-bit dual PWMs (6 outputs total) |
| DMA Controllers | 6 |
| Comparators | Yes (integrated) |
| Operational Amplifiers | 3 internal op-amps |
| USB | USB 2.0 Full-Speed device |
| DMA Channels | 6 |
| Vectored Interrupts | Yes (3-cycle fixed latency) |
| Functional Safety (FuSa) | Supported with documentation |
| XLP (eXtreme Low Power) | Yes |
| Operating Temperature Range | -40 C to +85 C (Industrial) |
| Package | 28-pin SOIC (SO) |
| Mounting Type | Surface Mount |
| RoHS Status | Compliant |
PIC18F27Q43-I/SO Pin Configuration
| Pin 1 | RA0 — Analog/Digital I/O, ADC channel |
| Pin 2 | RA1 — Analog/Digital I/O, ADC channel |
| Pin 3 | RA2 — Analog/Digital I/O, ADC channel |
| Pin 4 | RA3 — Analog/Digital I/O, ADC channel |
| Pin 5 | RA4 — Analog/Digital I/O |
| Pin 6 | RA5 — Analog/Digital I/O |
| Pin 7 | RA6 — Analog/Digital I/O |
| Pin 8 | RA7 — Analog/Digital I/O |
| Pin 9 | VSS — Ground reference |
| Pin 10 | VDD — Positive supply voltage (1.8V to 5.5V) |
| Pin 11 | RB0 — Digital I/O, INT0 |
| Pin 12 | RB1 — Digital I/O, INT1 |
| Pin 13 | RB2 — Digital I/O |
| Pin 14 | RB3 — Digital I/O |
| Pin 15 | RB4 — Digital I/O |
| Pin 16 | RB5 — Digital I/O |
| Pin 17 | RB6 — Digital I/O, ICSPCLK |
| Pin 18 | RB7 — Digital I/O, ICSPDAT |
| Pin 19 | VSS — Ground reference |
| Pin 20 | VDD — Positive supply voltage (1.8V to 5.5V) |
| Pin 21 | RC0 — Digital I/O |
| Pin 22 | RC1 — Digital I/O |
| Pin 23 | RC2 — Digital I/O |
| Pin 24 | RC3 — Digital I/O |
| Pin 25 | RC4 — Digital I/O |
| Pin 26 | RC5 — Digital I/O |
| Pin 27 | RC6 — Digital I/O, USB D+ |
| Pin 28 | RC7 — Digital I/O, USB D- |
Typical Applications
PIC18F27Q43-I/SO is suitable for 7 applications: BLDC and PMSM Motor Control, Capacitive Touch User Interface, USB HID / CDC Device, Industrial Sensor Hub, Smart Lighting and LED Drivers, Battery-Powered IoT Sensor Node, Appliance Control Boards.
BLDC and PMSM Motor Control
The PIC18F27Q43-I/SO is well suited for sensorless BLDC and PMSM motor control in 5V or 3.3V systems. Its three 16-bit dual PWMs provide six outputs with programmable dead-band, enabling complementary drive signals for three-phase half-bridges without external logic. The three internal op-amps sense shunt currents directly, while the ADCC samples them simultaneously with the back-EMF zero-cross detector. Six DMA channels move ADC samples to PWM duty registers without CPU loading, and the 64MHz CPU executes field-oriented control loops in single-digit microseconds.
Recommended
Capacitive Touch User Interface
The ADCC with built-in Capacitive Voltage Divider (CVD) makes the PIC18F27Q43-I/SO ideal for touch-button, slider, and wheel implementations in appliance and consumer UI. The CVD technique automates charge redistribution across multiple samples, providing high SNR touch detection without external analog components. Hardware averaging and oversampling further reduce noise sensitivity, allowing reliable operation under wet or noisy conditions. Direct-drive PWM outputs can backlight LEDs to confirm user input, while DMA offloads scan sequences from the CPU.
Recommended
USB HID / CDC Device
The PIC18F27Q43-I/SO integrates a USB 2.0 Full-Speed device controller with on-chip transceiver, eliminating the need for external USB PHY chips. Combined with 128KB Flash, this supports HID class devices (keyboards, mice, custom peripherals), CDC virtual COM ports, and vendor-specific control transfers used in test equipment and configuration tools. The 8KB RAM accommodates USB endpoint buffers plus application data, and 1KB EEPROM stores persistent descriptors and calibration data.
Recommended
Industrial Sensor Hub
In industrial 4-20mA loop-powered or RS-485 sensor hubs, the PIC18F27Q43-I/SO provides simultaneous ADC sampling via DMA, on-chip op-amps for signal conditioning, and three hardware comparators for threshold detection. The vectored interrupt controller with 3-cycle fixed latency ensures deterministic response to sensor events, while the 1.8-5.5V supply range simplifies battery-backed and 24V-derived rails. Functional safety (FuSa) documentation supports safety-related sensor interfaces in machinery.
Recommended
Smart Lighting and LED Drivers
The PIC18F27Q43-I/SO drives multi-channel LED lighting with up to six independent 16-bit PWM outputs for tunable white or RGB color mixing. The 16-bit resolution allows 65536 brightness steps per channel, eliminating visible flicker at low duty cycles. ADCC inputs measure ambient light and LED temperature for closed-loop brightness compensation, and DMA-driven PWM updates reduce CPU overhead. The 5.5V tolerant I/O directly interfaces to constant-current LED driver ICs.
Recommended
Battery-Powered IoT Sensor Node
The PIC18F27Q43-I/SO's XLP (eXtreme Low Power) technology and wide 1.8-5.5V supply make it ideal for battery-powered IoT nodes running from single-cell Li-ion or 3V coin cells. Sleep currents in the nanoamp range and wake-on-peripheral triggers minimize average power consumption. The ADCC with DMA can sample sensors autonomously while the CPU sleeps, and the built-in USB 2.0 supports direct charging-port firmware updates. EEPROM stores calibration and identification data without external memory.
Recommended
Appliance Control Boards
Washing machines, dishwashers, ovens, and HVAC controllers benefit from the PIC18F27Q43-I/SO's combination of motor-control PWMs, ADC touch sensing, and functional safety support. A single chip can drive a BLDC drum motor, read capacitive control buttons, monitor temperature with the 12-bit ADCC, and communicate via UART to a higher-level display module. The 28-SOIC package provides robust thermal margin and easy hand rework during service.
Recommended
Recommended Products Summary
Engineering reference data for PIC18F27Q43-I/SO — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC18F27Q43-I/SP | PIC18F27Q43-E/SO | PIC18F27Q43-I/SS | PIC18F27K42-I/SO | PIC18F26Q43-I/SO | PIC18F25Q43-I/SO |
|---|---|---|---|---|---|---|---|
| Package | 28-pin SOIC | 28-pin SPDIP | 28-pin SOIC - same | 28-pin SSOP | 28-pin SOIC - same | 28-pin SOIC - same | 28-pin SOIC - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Flash | 128 KB | 128 KB | 128 KB | 128 KB | 64 KB | 64 KB | 64 KB |
| RAM | 8 KB | 8 KB | 8 KB | 8 KB | 8 KB | 4 KB | 4 KB |
| CPU Frequency | 64 MHz | 64 MHz | 64 MHz | 64 MHz | 64 MHz | 64 MHz | 64 MHz |
| Operating Temperature | -40C to +85C (Industrial) | -40C to +85C | -40C to +125C (Extended) | -40C to +85C | -40C to +85C | -40C to +85C | -40C to +85C |
| ADC | 12-bit ADCC with CVD | 12-bit ADCC with CVD | 12-bit ADCC with CVD | 12-bit ADCC with CVD | 12-bit ADC (no CVD, no computation) | 12-bit ADCC with CVD | 12-bit ADCC with CVD |
| PWM | Three 16-bit dual PWMs (6 outputs) | Three 16-bit dual PWMs | Three 16-bit dual PWMs | Three 16-bit dual PWMs | Two CCP, two 16-bit PWM | Three 16-bit dual PWMs | Three 16-bit dual PWMs |
| USB | USB 2.0 Full-Speed device | USB 2.0 Full-Speed device | USB 2.0 Full-Speed device | USB 2.0 Full-Speed device | No USB | USB 2.0 Full-Speed device | USB 2.0 Full-Speed device |
| Unit Price (qty 1, as of 2026-09-27) | $3.42 | $3.85 | $3.62 | $3.55 | $2.95 | $2.85 | $2.75 |
Key Differentiators
- Six DMA controllers for offloaded data movement (vs PIC18F27K42-I/SO)
- 16-bit PWM with hardware dead-band and slope compensation (vs PIC18F26Q43-I/SO)
- ADCC with built-in Capacitive Voltage Divider (vs PIC18F26Q84-I/SO)
Design Notes
The PIC18F27Q43-I/SO operates from 1.8V to 5.5V on VDD. Place a 100nF decoupling capacitor within 5mm of each VDD/AVDD pin and a bulk 10uF ceramic on the supply rail. For ADC accuracy, drive AVDD from a filtered version of VDD and provide a dedicated 10uF + 100nF network to AVSS. Avoid switching the USB transceiver on/off while VDD is below 3.0V to prevent bus-latched states.
Route the USB D+/D- differential pair as a 90-ohm impedance matched pair with no stubs. Keep crystal traces (if using external OSC) short and guard them with a grounded ring. Place the ICSP header (RB6/RB7) at the board edge for programming access, and reserve the MCLR pin for a 10k pull-up plus 100nF reset capacitor for in-circuit debug reliability.
Estimated: at 64 MHz CPU and full peripheral activity, the SOIC-28 dissipates approximately 30-50 mW, well within the package's 100 C/W thermal resistance to ambient. Junction rise above ambient is below 5 C in typical 25 C environments. No heatsink is required; ensure the surrounding copper area is at least 50 mm^2 to spread heat from the central die pad.
Do not exceed 5.5V on any pin; the USB D+/D- lines have limited protection and should be clamped with TVS diodes for hot-plug events. The ADCC reference voltage must be initialized before ADC conversion to avoid garbage readings. PWM dead-band timing must be set in microseconds relative to the system clock, not instruction cycles, to avoid mis-synchronized complementary outputs.
For capacitive touch sensing via the ADCC CVD feature, route the touch sensor traces as short guarded electrodes to minimize parasitic capacitance to ground. Maintain at least 5mm spacing between adjacent touch sensors and avoid running noisy traces (PWM, USB) directly under the touch panel. Sample rate of 1-10 kHz per channel is typical; the ADCC averaging filter further rejects mains-frequency noise.
Compliance Information
RoHS and REACH compliant per Microchip product page. Functional Safety (FuSa) documentation available from Microchip; not AEC-Q100 qualified - automotive customers should use the PIC18F27Q43-E/SO with extended temperature.
