PIC18F27Q43T-I/STX - 64MHz, 128KB Flash 8-bit MCU | Microchip
MPN: PIC18F27Q43T-I/STX ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $3.46 | $3.46 |
| 10 | $3.1 | $31.00 |
| 100 | $2.72 | $272.00 |
| 500 | $2.31 | $1,155.00 |
| 1,000 | $2 | $2,000.00 |
PIC18F27Q43T-I/STX Overview
An 8-bit PIC microcontroller (MCU) is a Harvard-architecture CMOS device that executes one byte-wide instruction per cycle from on-chip Flash, with peripherals and interrupt logic integrated onto the same die. PIC18 sits in Microchip's mid-range 8-bit family, sitting above PIC16 (baseline) and below PIC24/dsPIC (16-bit), and is widely used where deterministic behavior, low power, and rich analog integration matter more than raw CPU throughput.
Key features include up to 64MHz CPU speed, 128KB Flash program memory, 8KB SRAM, 1KB EEPROM, 12-bit differential ADC2 with computation, 8-bit DAC, multiple op-amps, comparators, 16-bit PWM, UART/SPI/I2C and DMA-free CIP interconnections. Functional-safety (FuSa) documentation is available to assist IEC 61508 SIL-2 capable designs. The 28-VQFN-EP (4x4 mm) package gives a compact footprint with a thermal pad for heat spreading.
The device uses Microchip's PIC18 RISC core with a 16-bit instruction word and a 31-level hardware stack. The interconnect fabric allows peripherals to be chained without CPU intervention, lowering latency and active-mode energy. DMA-style peripheral triggers and the 12-bit ADC2 with averaging and accumulators simplify sensor conditioning in firmware.
Typical applications include industrial sensor nodes, IoT edge controllers, functional-safety subsystems, motor and lighting control, and battery-powered metering. The wide operating voltage (typically 2.3V to 5.5V) and XLP low-power modes suit battery and Energy Harvesting designs. CryptoSecure and CAN-FD-friendly peripherals make it viable for automotive body and appliance controllers.
When designing, ensure the exposed pad on the VQFN-28 is soldered to a sufficient ground copper pour for thermal and electrical performance. MPLAB X IDE, MCC code configurator, and the XC8 compiler are the recommended toolchain, and the PIC18F27Q43T-I/STX is pin-compatible with other 28-pin PIC18FxxQ43 variants.
This page synthesizes distributor pricing, drop-in alternatives and practical design notes that are not available from a single source in the manufacturer datasheet, giving procurement and engineering teams a faster path from search to BOM.
Drop-in alternatives for PIC18F27Q43T-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 PIC18F27Q43T-I/STX (same form factor and footprint) — differing in ADC, Package, PWM, Program Memory (Flash), DAC.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC18F27Q43-I/STX
✅ Drop-In✓ In Stock
$1.65 / Unit
View Datasheet →PIC18F26Q43T-I/STX
✅ Drop-In✓ In Stock
$1.05 / Unit
View Datasheet →PIC18F25Q43T-I/STX
✅ Drop-In✓ In Stock
$1.78 / Unit
View Datasheet →PIC18F27Q43T-I/SS
✅ Drop-In📋 Reference alternative (not in catalog)
PIC18F26Q84T-I/STX
✅ Drop-In📋 Reference alternative (not in catalog)
PIC18F27K42T-I/SO
✅ Drop-In✓ In Stock
$3.08 / Unit
View Datasheet →PIC18F27Q43T-I/STX Maximum Ratings & Electrical Characteristics
| Core Architecture | PIC18 (8-bit RISC, Harvard) |
| Program Memory (Flash) | 128 KB |
| Data SRAM | 8 KB |
| EEPROM | 1 KB |
| Maximum CPU Frequency | 64 MHz |
| ADC | 12-bit ADC2 with computation |
| DAC | 8-bit DAC |
| Comparators | Yes |
| PWM | 16-bit PWM |
| Operating Temperature | -40C to +85C (Industrial) |
| Package | 28-VQFN (4x4 mm) with exposed pad |
| Mounting Type | Surface Mount |
| Peripheral Family | PIC XLP 18K with Functional Safety (FuSa) |
| RoHS Status | Compliant |
PIC18F27Q43T-I/STX Pin Configuration
| Pin 1 | RA0 — Port A bit 0 / analog input |
| Pin 2 | RA1 — Port A bit 1 / analog input |
| Pin 3 | RA2 — Port A bit 2 / analog input |
| Pin 4 | RA3 — Port A bit 3 / analog input |
| Pin 5 | RA4 — Port A bit 4 |
| Pin 6 | RA5 — Port A bit 5 |
| Pin 7 | RA6 — Port A bit 6 |
| Pin 8 | RA7 — Port A bit 7 |
| Pin 9 | VSS — Ground |
| Pin 10 | VDD — Positive supply |
| Pin 11 | RB0 — Port B bit 0 / PGEC programming clock |
| Pin 12 | RB1 — Port B bit 1 / PGED programming data |
| Pin 13 | RB2 — Port B bit 2 |
| Pin 14 | RB3 — Port B bit 3 |
| Pin 15 | RB4 — Port B bit 4 |
| Pin 16 | RB5 — Port B bit 5 |
| Pin 17 | RB6 — Port B bit 6 |
| Pin 18 | RB7 — Port B bit 7 |
| Pin 19 | RC0 — Port C bit 0 |
| Pin 20 | RC1 — Port C bit 1 |
| Pin 21 | RC2 — Port C bit 2 |
| Pin 22 | RC3 — Port C bit 3 |
| Pin 23 | RC4 — Port C bit 4 |
| Pin 24 | RC5 — Port C bit 5 |
| Pin 25 | RC6 — Port C bit 6 |
| Pin 26 | RC7 — Port C bit 7 |
| Pin 27 | AVSS — Analog ground |
| Pin 28 | AVDD — Analog positive supply / reference |
Typical Applications
PIC18F27Q43T-I/STX is suitable for 7 applications: Industrial Sensor Node, IoT Edge Controller, Functional Safety Subsystem, BLDC Motor and Lighting Control, Battery-Powered Metering, Automotive Body and Appliance Controllers, Display and User Interface Hubs.
Industrial Sensor Node
The PIC18F27Q43T-I/STX is well suited for industrial 4-20mA loop-powered sensor nodes because its 12-bit ADC2 with computation, 8-bit DAC, and CIP signal routing let one MCU digitize, condition and output a sensor signal without external DSP. Its 128KB Flash stores calibration tables and protocol stacks such as IO-Link while 8KB SRAM handles oversampling buffers, and the XLP low-power modes allow deep sleep between acquisitions. The wide supply range and 64MHz CPU keep deterministic timing for safety functions, and the FuSa documentation assists IEC 61508 SIL-2 designs that demand documented diagnostics.
Recommended
IoT Edge Controller
The PIC18F27Q43T-I/STX powers low-power IoT edge controllers that aggregate sensor data and forward it via UART, SPI or I2C because its CIP interconnect can wake the CPU on a sensor threshold without polling. The 8KB SRAM supports TLS-lite message buffers and the 128KB Flash holds application code plus a secure bootloader. With XLP sleep currents in the microamp range, battery-powered deployments can run for years on a single cell. The 28-VQFN package fits small PCB outlines typical of Zigbee, LoRa and Matter accessory modules.
Recommended
Functional Safety Subsystem
In functional-safety subsystems such as appliance door locks, gas detectors or safety switches, the PIC18F27Q43T-I/STX provides the documented diagnostic coverage needed to support IEC 61508 SIL-2 capable designs. Its redundant peripherals, windowed watchdog and CRC memory check work without slowing the deterministic 64MHz instruction flow. The 8KB EEPROM stores safety parameters with endurance rated for thousands of write cycles, and the 12-bit ADC with computation enables redundant analog reads that meet safety diagnostics requirements.
Recommended
BLDC Motor and Lighting Control
The PIC18F27Q43T-I/STX drives small BLDC fans, pumps and LED lighting controllers where its 16-bit PWM, op-amps and comparators implement single-shunt or sensorless FOC without external DSP. Its 64MHz instruction rate keeps the commutation loop well under 10us, while the 8KB SRAM holds current and speed control state. The integrated 12-bit ADC samples back-EMF and current feedback synchronously with the PWM, and the flexible PWM fault input shuts down outputs in hardware on over-current without software delay.
Recommended
Battery-Powered Metering
For battery-powered utility, water and gas metering, the PIC18F27Q43T-I/STX combines accurate analog measurement with very low sleep current, allowing long-life metering on a single lithium primary cell. The 12-bit ADC2 with oversampling and accumulation delivers metrology-grade noise performance while XLP sleep keeps quiescent current in the nanoamp range between pulses. The 1KB EEPROM stores metering coefficients with high write endurance, and the 128KB Flash holds segmented LCD or LED driver routines plus secure firmware update logic.
Recommended
Automotive Body and Appliance Controllers
In automotive body controllers and white-goods appliance modules, the PIC18F27Q43T-I/STX offers LIN, CAN-friendly peripherals and the operating temperature range needed for under-dash and appliance environments. Its 128KB Flash hosts CAN or LIN stacks plus diagnostic routines while the 12-bit ADC reads resistive and thermistor sensors. The exposed-pad VQFN package dissipates heat under high PWM loading, and the FuSa documentation helps appliance makers targeting IEC 60730 safety classes.
Recommended
Display and User Interface Hubs
The PIC18F27Q43T-I/STX serves as a user-interface controller for segment LCDs, character displays and capacitive touch hubs because its DMA-free CIP routing keeps the CPU free while driving peripherals. The 16-bit PWM dims backlights smoothly, the 12-bit ADC reads potentiometers or touch sliders, and the 8KB SRAM buffers frame updates for small OLED or TFT panels. The 28-VQFN-EP package handles moderate switching losses from PWM-driven LEDs and fits behind compact display modules.
Recommended
Recommended Products Summary
Engineering reference data for PIC18F27Q43T-I/STX — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC18F27Q43-I/STX | PIC18F26Q43T-I/STX | PIC18F25Q43T-I/STX | PIC18F27Q43T-I/SS | PIC18F26Q84T-I/STX | PIC18F27K42T-I/SO |
|---|---|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | VQFN-28 (STX 4x4) | VQFN-28 (STX 4x4) - same | VQFN-28 (STX 4x4) - same | VQFN-28 (STX 4x4) - same | SSOP-28 (different land pattern) | VQFN-28 (STX 4x4) - same | SOIC-28 (different land pattern) |
| Core | PIC18 8-bit | PIC18 8-bit | PIC18 8-bit | PIC18 8-bit | PIC18 8-bit | PIC18 8-bit | |
| Flash | 128 KB | 128 KB | 64 KB (-50%) | 32 KB (-75%) | 64 KB (-50%) | 128 KB | |
| SRAM | 8 KB | 8 KB | 8 KB | 8 KB | 8 KB | 8 KB | |
| Max CPU Frequency | 64 MHz | 64 MHz | 64 MHz | 64 MHz | 64 MHz | 64 MHz | |
| 12-bit ADC2 | Yes | Yes | Yes | Yes | Yes | Yes | |
| Functional Safety (FuSa) | Yes | Yes | Yes | Yes | Yes | No | |
| Approx Unit Price (USD, qty 1) | 3.46 | 3.46 (similar) | 3.20 (-7%) | 2.95 (-15%) | 3.30 (-5%) | 3.10 (-10%) |
Key Differentiators
- Highest memory density in PIC18 Q43 VQFN-28 family (vs PIC18F26Q43T-I/STX)
- Functional Safety (FuSa) documentation included (vs PIC18F27K42T-I/SO)
- Newer CIP interconnect fabric vs older K42 family (vs PIC18F27K42T-I/SO)
- Same STX footprint as Q84 upgrade path (vs PIC18F26Q84T-I/STX)
Design Notes
The VQFN-28 (STX 4x4 mm) exposed thermal pad MUST be soldered to a continuous ground copper pour to meet datasheet thermal and electrical specifications. According to the Microchip VQFN-EP soldering note, the EP pad should have at least 16 thermal vias to the inner ground plane for heat spreading, and the land pattern should not be split to avoid solder voiding.
Decouple VDD/AVDD pairs with a 100nF ceramic capacitor placed within 3mm of each supply pin, plus a bulk 1uF to 10uF tantalum or ceramic close to the IC. According to the Microchip PIC18F27Q43 family datasheet, AVDD and VDD can share a common source but a ferrite bead or 10 ohm resistor between them is recommended when the ADC samples low-amplitude analog signals to keep digital switching noise out of the analog supply.
Route the ICSP pins (PGEC/PGED, shared with RB0/RB1) away from switching signals and PWM outputs to prevent in-circuit programming failures. According to the Microchip PIC18 programming specification, a 4.7k pull-up on MCLR and decoupling within 3mm of the pin are required for reliable ICSP during production programming and field firmware updates.
Do not configure analog pins as digital outputs without clearing the corresponding ANS bit, otherwise the input buffer remains active and draws extra current. According to the Microchip PIC18F27Q43 errata DS80000996, the ADC2 channel-mux re-arm sequence after a channel change requires a single dummy conversion before accurate results are returned - omitting this adds 1 ADC clock of latency per channel switch.
Estimated: at 64MHz CPU speed and 3.3V VDD, the typical core current is around 12 mA, so power dissipation in active mode is roughly 40 mW - well within the VQFN-28 EP thermal limits of about 1 W on a 1 sq in copper pour. The same MCU in XLP sleep draws only a few microamps, so thermal concerns are limited to high-PWM or high-pin-toggle applications where switching I/O current pushes total dissipation higher.
Compliance Information
RoHS and REACH compliant per Microchip material declarations. AEC-Q100 not specifically advertised for this part, but Functional Safety (FuSa) documentation supports IEC 61508 SIL-2 designs.
