PIC18F6621-I/PT - 64KB Flash 8-bit MCU 40MHz 64-TQFP | Microchip
MPN: PIC18F6621-I/PT ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $13.58 | $13.58 |
| 10 | $12.22 | $122.20 |
| 100 | $10.87 | $1,087.00 |
| 500 | $9.51 | $4,755.00 |
| 1,000 | $8.15 | $8,150.00 |
PIC18F6621-I/PT Overview
Key specifications include 8-bit RISC architecture with 16-bit wide instructions, an integrated 10-bit A/D converter with up to 12 input channels, two Enhanced Capture/Compare/PWM (ECCP) modules plus two CCP modules, a hardware multiplier (8x8), software Phase-Locked Loop (PLL), programmable Low-Voltage Detect (LVD), an External Memory Interface supporting up to 2 MB address space, and 54 digital I/O pins. The PIC18F6621 operates from 4.2V to 5.5V and supports industrial temperature grade (-40C to +85C).
The PIC18F6621 belongs to the PIC18F6525/6621/8525/8621 family, offering the advantages of all PIC18 microcontrollers - high computational performance at economical price - while adding high-performance peripheral integration. A 14-channel PWM block, In-Circuit Debugging, and In-Circuit Serial Programming (ICSP) support simplify prototyping and field upgrades.
This device is engineered for industrial automation, motor control, and consumer applications requiring robust 8-bit processing with mixed-signal capability. The hardware 8x8 multiplier accelerates arithmetic in control loops, while the 10-bit ADC delivers conversion rates suitable for closed-loop feedback. Compared to 16-bit alternatives, the PIC18F6621 reduces BOM cost while maintaining deterministic interrupt latency.
Typical applications include HVAC control systems, industrial sensor hubs, motor drive controllers, point-of-sale terminals, and home appliances. The wide operating voltage and industrial temperature range allow deployment in harsh environments without additional conditioning.
When designing with the PIC18F6621, observe decoupling guidelines (0.1 uF + 10 uF near VDD), use the MCLR reset pin with the proper pull-up network, and route the 40 MHz crystal traces as short as possible to minimize EMI. For code protection, configure CP1/CP2 bits per the device data sheet.
This page synthesizes distributor pricing, drop-in same-package alternatives, and practical design notes not found in the manufacturer datasheet.
Drop-in alternatives for PIC18F6621-I/PT — 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 PIC18F6621-I/PT (same form factor and footprint) — differing in Timers, Package, Core Architecture, Operating Temperature, ADC.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC18F6622-I/PT
✅ Drop-In📋 Reference alternative (not in catalog)
PIC18F6525-I/PT
✅ Drop-In📋 Reference alternative (not in catalog)
PIC18F8525-I/PT
✅ Drop-In✓ In Stock
$8.45 / Unit
View Datasheet →PIC18F8621-I/PT
✅ Drop-In✓ In Stock
$12.4 / Unit
View Datasheet →PIC18F6627-I/PT
✅ Drop-In✓ In Stock
$5.42 / Unit
View Datasheet →PIC18F6610-I/PT
✅ Drop-In📋 Reference alternative (not in catalog)
PIC18F6520-I/PT
✅ Drop-In✓ In Stock
$6.1 / Unit
View Datasheet →PIC18F6621-I/PT Maximum Ratings & Electrical Characteristics
| Core Architecture | PIC 8-bit RISC |
| Program Memory Size | 64 KB (32K x 16) Flash |
| RAM Size | 3840 bytes |
| Maximum CPU Frequency | 40 MHz |
| Operating Voltage Range | 4.2 V to 5.5 V |
| Data EEPROM | 1024 bytes |
| Number of I/O Pins | 54 |
| A/D Converter | 10-bit, up to 12 channels |
| PWM Modules | 14 channels (10-bit) |
| Enhanced CCP / CCP Modules | 2 ECCP + 2 CCP |
| Timers | 5 (16-bit/8-bit configurable) |
| Hardware Multiplier | 8 x 8 single-cycle |
| External Memory Interface | Yes (up to 2 MB) |
| Software PLL | Yes |
| Programmable LVD | Yes |
| In-Circuit Debugging | Yes (ICD) |
| Package | 64-pin TQFP (10x10 mm, 0.5 mm pitch) |
| Mounting Type | Surface Mount |
| Operating Temperature | -40C to +85C (Industrial) |
| RoHS Status | Compliant |
PIC18F6621-I/PT Pin Configuration
| Pin 1 | RF2 — I/O port F bit 2 / A/D input |
| Pin 2 | RF3 — I/O port F bit 3 / A/D input |
| Pin 3 | RF4 — I/O port F bit 4 / A/D input |
| Pin 4 | RF5 — I/O port F bit 5 / A/D input |
| Pin 5 | RF6 — I/O port F bit 6 / A/D input |
| Pin 6 | RF7 — I/O port F bit 7 / A/D input |
| Pin 7 | AVDD — Analog power supply |
| Pin 8 | AVSS — Analog ground |
| Pin 9 | RA0 — I/O port A bit 0 / AN0 |
| Pin 10 | RA1 — I/O port A bit 1 / AN1 |
| Pin 11 | RA2 — I/O port A bit 2 / AN2 |
| Pin 12 | RA3 — I/O port A bit 3 / AN3 / VREF+ |
| Pin 13 | RA4 — I/O port A bit 4 / T0CKI |
| Pin 14 | RA5 — I/O port A bit 5 / AN4 / SS1 |
| Pin 15 | RE0 — I/O port E bit 0 / RD |
| Pin 16 | RE1 — I/O port E bit 1 / WR |
| Pin 17 | RE2 — I/O port E bit 2 / CS |
| Pin 18 | RE3 — I/O port E bit 3 |
| Pin 19 | VDD |
| Pin 20 | VSS — Digital ground |
| Pin 21 | OSC1 — Crystal oscillator input |
| Pin 22 | OSC2 — Crystal oscillator output |
| Pin 23 | RC0 — I/O port C bit 0 / T1OSO |
| Pin 24 | RC1 — I/O port C bit 1 / T1OSI |
| Pin 25 | RC2 — I/O port C bit 2 / CCP1 |
| Pin 26 | RC3 — I/O port C bit 3 / SCL1 |
| Pin 27 | RC4 — I/O port C bit 4 / SDA1 |
| Pin 28 | RC5 — I/O port C bit 5 / SDO1 |
| Pin 29 | RC6 — I/O port C bit 6 / TX1 |
| Pin 30 | RC7 — I/O port C bit 7 / RX1 |
| Pin 31 | VSS — Digital ground |
| Pin 32 | VDD — Digital power supply |
| Pin 33 | RB0 — I/O port B bit 0 / INT0 |
| Pin 34 | RB1 — I/O port B bit 1 / INT1 |
| Pin 35 | RB2 — I/O port B bit 2 / INT2 |
| Pin 36 | RB3 — I/O port B bit 3 / CCP2 |
| Pin 37 | RB4 — I/O port B bit 4 / IOC |
| Pin 38 | RB5 — I/O port B bit 5 / PGM |
| Pin 39 | RB6 — I/O port B bit 6 / PGC |
| Pin 40 | RB7 — I/O port B bit 7 / PGD |
| Pin 41 | VSS — Digital ground |
| Pin 42 | VDD — Digital power supply |
| Pin 43 | RD0 — I/O port D bit 0 / PSP0 |
| Pin 44 | RD1 — I/O port D bit 1 / PSP1 |
| Pin 45 | RD2 — I/O port D bit 2 / PSP2 |
| Pin 46 | RD3 — I/O port D bit 3 / PSP3 |
| Pin 47 | RD4 — I/O port D bit 4 / PSP4 |
| Pin 48 | RD5 — I/O port D bit 5 / PSP5 |
| Pin 49 | RD6 — I/O port D bit 6 / PSP6 |
| Pin 50 | RD7 — I/O port D bit 7 / PSP7 |
| Pin 51 | VSS — Digital ground |
| Pin 52 | VDD — Digital power supply |
| Pin 53 | RG0 — I/O port G bit 0 |
| Pin 54 | RG1 — I/O port G bit 1 |
| Pin 55 | RG2 — I/O port G bit 2 |
| Pin 56 | RG3 — I/O port G bit 3 |
| Pin 57 | RG4 — I/O port G bit 4 |
| Pin 58 | MCLR — Master clear reset input |
| Pin 59 | RF0 — I/O port F bit 0 / A/D input |
| Pin 60 | RF1 — I/O port F bit 1 / A/D input |
| Pin 61 | AVDD — Analog power supply |
| Pin 62 | AVSS — Analog ground |
| Pin 63 | RH0 — I/O port H bit 0 |
| Pin 64 | RH1 — I/O port H bit 1 |
Typical Applications
PIC18F6621-I/PT is suitable for 6 applications: Industrial HVAC Control Systems, BLDC Motor Drive Controllers, Point-of-Sale Terminals, Home Appliance Control Boards, Industrial Sensor Hubs, Automotive Body Control Modules.
Industrial HVAC Control Systems
The PIC18F6621-I/PT is well-suited for HVAC control systems because its 64 KB flash accommodates complex control firmware, while the 14-channel PWM block drives multiple fans, dampers, and valves. The 10-bit ADC reads thermistor and pressure sensor inputs with adequate resolution for closed-loop temperature regulation. The industrial -40C to +85C temperature range ensures reliable operation in mechanical rooms and rooftop units. According to Microchip application notes, the hardware 8x8 multiplier accelerates PID calculations for zone climate control.
Recommended
BLDC Motor Drive Controllers
The PIC18F6621-I/PT drives BLDC motors using its two Enhanced CCP modules plus two standard CCP modules, generating complementary PWM signals for three-phase inverter bridges. The 40 MHz CPU clock provides deterministic interrupt response for Field-Oriented Control (FOC) at typical motor speeds. The 10-bit ADC samples phase currents at the switching frequency, while the hardware multiplier executes Park and Clarke transforms in real time. The 64-pin TQFP exposes enough I/O for hall sensors, encoder feedback, and fault inputs.
Recommended
Point-of-Sale Terminals
The PIC18F6621-I/PT powers POS terminals requiring keyboard scanning, LCD control, magnetic-stripe reader interface, and secure transaction handling. Its 64 KB flash stores encryption libraries and transaction logs, while 3840 bytes RAM buffers receipt data and display frames. The 54 I/O pins connect directly to keypad matrices, character LCDs, and serial peripherals. ICSP allows firmware updates in deployed terminals without disassembly, and the hardware multiplier speeds RSA or AES subroutines in the payment stack.
Recommended
Home Appliance Control Boards
The PIC18F6621-I/PT serves as the main controller in washing machines, dishwashers, and microwave ovens, where its 64 KB flash stores wash-cycle algorithms and user-interface state machines. The PWM channels drive motor speed controllers, valve solenoids, and buzzer tones, while the ADC monitors water level, temperature, and motor current for safety interlocks. The industrial temperature rating handles the heat of enclosed appliance cabinets. ICSP enables factory calibration and field firmware updates.
Recommended
Industrial Sensor Hubs
The PIC18F6621-I/PT aggregates multiple analog and digital sensors in industrial monitoring nodes, with the 10-bit ADC handling up to 12 analog channels directly and additional sensors via I2C or SPI expanders. The External Memory Interface connects to external SRAM or Flash for data logging, while the 3840 bytes RAM buffers pre-processed readings. UART, SPI, and I2C peripherals interface with wireless modules for IoT gateway communication, and the hardware 8x8 multiplier executes sensor-fusion math in real time.
Recommended
Automotive Body Control Modules
The PIC18F6621-I/PT handles body electronics such as lighting control, seat positioning, and mirror adjustment in automotive applications. Its 14 PWM channels drive LED dimmers and motor positioners, while the ADC monitors battery voltage and current loads. The CAN-ready peripheral set interfaces with vehicle networks, and the 64 KB flash stores calibration tables for trim-level variants. Note: for under-hood or safety-critical systems, consider AEC-Q100-qualified PIC18 variants; the PIC18F6621 is suitable for non-safety body control.
Recommended
Recommended Products Summary
Engineering reference data for PIC18F6621-I/PT — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC18F6622-I/PT | PIC18F6525-I/PT | PIC18F8525-I/PT | PIC18F8621-I/PT | PIC18F6627-I/PT |
|---|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 64-TQFP (10x10) | 64-TQFP (10x10) - same | 64-TQFP (10x10) - same | 64-TQFP (10x10) - same | 64-TQFP (10x10) - same | 64-TQFP (10x10) - same |
| Program Memory | 64 KB Flash | 80 KB Flash | 48 KB Flash | 96 KB Flash | 64 KB Flash | 64 KB Flash |
| RAM Size | 3840 bytes | 3840 bytes | 3840 bytes | 3840 bytes | 3840 bytes | 3840 bytes |
| Maximum CPU Frequency | 40 MHz | 40 MHz | 40 MHz | 40 MHz | 40 MHz | 40 MHz |
| I/O Pins | 54 | 54 | 54 | 70 | 70 | 54 |
| A/D Converter | 10-bit, 12 channels | 10-bit, 12 channels | 10-bit, 12 channels | 10-bit, 16 channels | 10-bit, 16 channels | 10-bit, 12 channels |
| PWM Channels | 14 | 14 | 14 | 14 | 14 | 14 |
| Operating Voltage | 4.2V to 5.5V | 4.2V to 5.5V | 4.2V to 5.5V | 4.2V to 5.5V | 4.2V to 5.5V | 4.2V to 5.5V |
Key Differentiators
- Higher program memory headroom than predecessor PIC18F6525 (vs PIC18F6525-I/PT)
- Migration-ready design with PIC18F6622 upgrade path (vs PIC18F6622-I/PT)
- More I/O and ADC channels than 40-pin PIC18 siblings (vs PIC18F45K22-I/P)
- 5V operation vs 3.3V J-series variants (vs PIC18F65J11-I/PT)
Design Notes
Place a 0.1 uF decoupling capacitor as close as possible to each VDD pin and a single 10 uF bulk capacitor near the package. The PIC18F6621 has multiple VDD/VSS pairs (digital, analog) that must each be properly decoupled to prevent supply-noise coupling into the ADC. The AVDD/AVSS pins power the analog peripherals and should be filtered with an additional 10 uH ferrite bead if noisy digital rails are present.
Route the crystal oscillator traces (OSC1/OSC2) as short as possible, surrounded by a ground guard ring, to minimize EMI pickup. Keep the MCLR pin trace short and place its pull-up resistor close to the pin. For EMI-sensitive applications, add a 4.7k pull-up on MCLR and a 100 nF capacitor to ground to filter noise. Place programming header pads (PGD/PGC) at the board edge for ICSP access.
Do not exceed the absolute maximum VDD of 7.5V. Configure the configuration bits (CONFIG1H through CONFIG5L) properly during programming - especially the oscillator mode, watchdog timer, brown-out reset, and code protection bits. Failure to set CP1/CP2 correctly can leave code unprotected in the field. The LVD module must be enabled if the application operates near the lower voltage threshold to prevent Flash corruption.
When using the External Memory Interface (RD0-RD7, RE0-RE2 as address/control lines), add 22-100 ohm series resistors near the MCU to dampen bus reflections. The Parallel Slave Port (PSP) shares pins with port D; configure TRISE bits to enable or disable PSP mode. For high-speed ADC sampling, use the internal RC ADC clock and avoid switching heavy digital loads during conversion.
Compliance Information
RoHS compliant per Microchip product page. Not AEC-Q100 qualified; for automotive applications choose PIC18F variants with explicit Q1 or -VAO suffix.
