PIC18LF8680T-I/PT - 40MHz 8-bit MCU 64KB Flash TQFP-80 | Microchip
MPN: PIC18LF8680T-I/PT ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $5.63 | $5.63 |
| 10 | $5.18 | $51.80 |
| 100 | $4.62 | $462.00 |
| 500 | $4.21 | $2,105.00 |
| 1,000 | $3.85 | $3,850.00 |
PIC18LF8680T-I/PT Overview
An 8-bit microcontroller is a single-chip computer that integrates a CPU, program memory (ROM/FLASH), working memory (RAM), and a configurable set of digital I/O peripherals on one die. PIC18F devices in particular sit in the upper tier of Microchip's 8-bit line, combining a RISC-like Harvard architecture with a 16-bit-wide instruction set, hardware multiplier, and rich peripheral integration (CAN, ADC, PWM, I2C/SPI, USART). The 8-bit MCU hierarchy runs: PIC18F -> 8-bit PIC -> PIC microcontroller -> microcontroller (MCU) -> embedded processor -> semiconductor. It is the workhorse tier for industrial control, automotive body electronics, and human-machine interface designs where deterministic bit-manipulation and low BOM cost matter more than raw MHz.
Key differentiating features include 64KB of self-programmable FLASH for in-application firmware updates, an enhanced USART supporting RS-232/RS-485, a 10-bit ADC with up to 16 channels, multiple timer modules, and a 10 MIPS instruction throughput at 40MHz. The 80-pin TQFP package provides 68 user I/O pins, sufficient to drive parallel LCDs, keypad matrices, and external memory buses without multiplexing. Code protection fuses guard intellectual property.
The LF8680 uses Microchip's standard PIC18 core with a 2-stage instruction pipeline, an 8x8 hardware multiplier for integer math acceleration, and an internal oscillator block. The 16-bit instruction word gives the device a large address space (2MB linear) while preserving the byte-oriented peripheral register model familiar to PIC developers. The architecture is documented in the PIC18F Reference Manual.
Typical applications include industrial automation controllers, automotive instrument clusters, building-automation HVAC nodes, smart-meter data concentrators, and point-of-sale terminals that need CAN/Ethernet-style connectivity via external transceivers plus abundant GPIO for legacy parallel interfaces.
When designing with this part, verify your power-rail decoupling budget matches the 68 I/O simultaneous-switching worst case, and budget enough FLASH endurance margin (100K erase/write cycles typical) if your design performs frequent firmware updates. The T suffix indicates tape-and-reel packaging, while the I suffix denotes the industrial -40C to +85C temperature grade.
This page synthesizes verified distributor pricing, in-package drop-in alternatives, and practical design considerations not consolidated in the standalone Microchip datasheet, giving procurement and engineering teams a single reference for the PIC18LF8680T-I/PT.
Drop-in alternatives for PIC18LF8680T-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 PIC18LF8680T-I/PT (same form factor and footprint) — differing in Package, Operating Temperature, ADC, Core Architecture, Program Memory (Flash).
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC18LF8680-I/PT
✅ Drop-In✓ In Stock
$7.99 / Unit
View Datasheet →PIC18LF8585-I/PT
✅ Drop-In✓ In Stock
$6.2 / Unit
View Datasheet →PIC18LF6680T-I/PT
✅ Drop-In✓ In Stock
$6.4 / Unit
View Datasheet →PIC18LF8525-I/PT
✅ Drop-In✓ In Stock
$5.48 / Unit
View Datasheet →PIC18LF8680T-I/PT Maximum Ratings & Electrical Characteristics
| Core Architecture | PIC 8-bit (Harvard, RISC-like) |
| Family | PIC18F |
| Core Frequency | 40 MHz (10 MIPS) |
| Program Memory (FLASH) | 64 KB (32K x 16) |
| RAM | 3.25 KB (3328 bytes) |
| I/O Pins | 68 |
| Supply Voltage | 4.2 V to 5.5 V |
| Operating Temperature | -40C to +85C (Industrial, I suffix) |
| Package | TQFP-80 (12 x 12 mm, 1.0 mm pitch) |
| Mounting Type | Surface Mount |
| Packaging | Tape & Reel (T suffix) |
| Lead Finish | Lead-free (Matte Tin) |
| ROM Type | Flash |
| Lifecycle Stage | Active |
| RoHS Status | Compliant |
PIC18LF8680T-I/PT Pin Configuration
| Pin 1 | OSC1 — Oscillator input / external clock |
| Pin 2 | OSC2 — Oscillator output |
| Pin 3 | MCLR — Master Clear (reset, active low) |
| Pin 4 | RA0 — Digital I/O / analog input |
| Pin 5 | RA1 — Digital I/O / analog input |
| Pin 6 | RA2 — Digital I/O / analog input |
| Pin 7 | RA3 — Digital I/O / analog input |
| Pin 8 | RA4 — Digital I/O / analog input |
| Pin 9 | RA5 — Digital I/O / analog input |
| Pin 10 | RA6 — Digital I/O / analog input |
| Pin 11 | VDD — Power supply (5V) |
| Pin 12 | VSS — Ground reference |
| Pin 13 | RB0 — Digital I/O / interrupt-on-change |
| Pin 14 | RB1 — Digital I/O / interrupt-on-change |
| Pin 15 | RB2 — Digital I/O / interrupt-on-change |
| Pin 16 | RB3 — Digital I/O / interrupt-on-change |
| Pin 17 | RB4 — Digital I/O / interrupt-on-change |
| Pin 18 | RB5 — Digital I/O / interrupt-on-change |
| Pin 19 | RB6 — Digital I/O / ICD clock |
| Pin 20 | RB7 — Digital I/O / ICD data |
| Pin 21 | RC0 — Digital I/O / PWM output |
| Pin 22 | RC1 — Digital I/O / PWM output |
| Pin 23 | RC2 — Digital I/O / PWM output |
| Pin 24 | RC3 — Digital I/O / PWM output |
| Pin 25 | RC4 — Digital I/O / PWM output |
| Pin 26 | RC5 — Digital I/O / PWM output |
| Pin 27 | RC6 — Digital I/O / USART TX |
| Pin 28 | RC7 — Digital I/O / USART RX |
| Pin 29 | RD0 — Digital I/O / PSP data |
| Pin 30 | RD1 — Digital I/O / PSP data |
| Pin 31 | RD2 — Digital I/O / PSP data |
| Pin 32 | RD3 — Digital I/O / PSP data |
| Pin 33 | RD4 — Digital I/O / PSP data |
| Pin 34 | RD5 — Digital I/O / PSP data |
| Pin 35 | RD6 — Digital I/O / PSP data |
| Pin 36 | RD7 — Digital I/O / PSP data |
| Pin 37 | RE0 — Digital I/O / PSP control |
| Pin 38 | RE1 — Digital I/O / PSP control |
| Pin 39 | RE2 — Digital I/O / PSP control |
| Pin 40 | RE3 — Digital I/O / PSP control |
| Pin 41 | VDD — Power supply (5V) |
| Pin 42 | VSS — Ground reference |
| Pin 43 | RF0 — Digital I/O / analog input |
| Pin 44 | RF1 — Digital I/O / analog input |
| Pin 45 | RF2 — Digital I/O / analog input |
| Pin 46 | RF3 — Digital I/O / analog input |
| Pin 47 | RF4 — Digital I/O / analog input |
| Pin 48 | RF5 — Digital I/O / analog input |
| Pin 49 | RF6 — Digital I/O / analog input |
| Pin 50 | RF7 — Digital I/O / analog input |
| Pin 51 | RG0 — Digital I/O / PSP control |
| Pin 52 | RG1 — Digital I/O / PSP control |
| Pin 53 | RG2 — Digital I/O / PSP control |
| Pin 54 | RG3 — Digital I/O / PSP control |
| Pin 55 | RG4 — Digital I/O / PSP control |
| Pin 56 | RG5 — Digital I/O |
| Pin 57 | RH0 — Digital I/O |
| Pin 58 | RH1 — Digital I/O |
| Pin 59 | RH2 — Digital I/O |
| Pin 60 | RH3 — Digital I/O |
| Pin 61 | RH4 — Digital I/O |
| Pin 62 | RH5 — Digital I/O |
| Pin 63 | RH6 — Digital I/O |
| Pin 64 | RH7 — Digital I/O |
| Pin 65 | RJ0 — Digital I/O |
| Pin 66 | RJ1 — Digital I/O |
| Pin 67 | RJ2 — Digital I/O |
| Pin 68 | RJ3 — Digital I/O |
| Pin 69 | RJ4 — Digital I/O |
| Pin 70 | RJ5 — Digital I/O |
| Pin 71 | RJ6 — Digital I/O |
| Pin 72 | RJ7 — Digital I/O |
| Pin 73 | RK0 — Digital I/O |
| Pin 74 | RK1 — Digital I/O |
| Pin 75 | RK2 — Digital I/O |
| Pin 76 | RK3 — Digital I/O |
| Pin 77 | RK4 — Digital I/O |
| Pin 78 | RK5 — Digital I/O |
| Pin 79 | VDD — Power supply (5V) |
| Pin 80 | VSS — Ground reference |
Typical Applications
PIC18LF8680T-I/PT is suitable for 6 applications: Industrial Automation Controller, Automotive Instrument Cluster, Building Automation HVAC Node, Smart Meter Data Concentrator, Point-of-Sale Terminal, Medical Monitoring Peripheral.
Industrial Automation Controller
The PIC18LF8680T-I/PT suits PLC-style industrial controllers because of its 68 GPIO pins and 64 KB FLASH for ladder-logic interpreters and Modbus stacks. The 40 MHz / 10 MIPS core easily services deterministic scan loops in the 1-5 ms range while leaving MIPS budget for HMIs and filtering. Industrial -40C to +85C operation tolerates cabinet temperatures near motor drives. The 4.2V-5.5V supply directly interfaces 5V sensor buses and 24V opto-isolated inputs through dividers. Pair with Microchip MCP2515 for CANopen connectivity.
Recommended
Automotive Instrument Cluster
The PIC18LF8680T-I/PT powers 5V automotive gauge clusters with its 68 I/O driving stepper-motor coils, LCD segments, and CAN-bus diagnostics. Its 64 KB FLASH holds graphic gauge libraries and OBD-II PIDs while the 3.25 KB RAM buffers trip data. At 40 MHz, the device handles CAN message parsing plus simultaneous gauge animation at 60 Hz refresh. Industrial temperature grade suits cabin environments; for under-hood applications the AEC-Q100 qualified PIC18F46K80 family should be selected instead.
Recommended
Building Automation HVAC Node
The PIC18LF8680T-I/PT serves BACnet/Modbus HVAC controllers thanks to its large FLASH for scheduling tables and trend logs. The 68 I/O interface thermistors, damper actuators, and 4-20 mA loops with the on-chip 10-bit ADC; the 5V core tolerates industrial sensor rail voltages. Industrial temperature grade survives rooftop and mechanical-room environments. Combined with RS-485 transceivers like MCP2551, the device forms the heart of a multi-zone VAV box controller.
Recommended
Smart Meter Data Concentrator
The PIC18LF8680T-I/PT aggregates consumption data from DLMS/COSEM or IEC 62056 smart meters using its 64 KB FLASH for protocol stacks and 68 I/O for multiple UARTs. The 40 MHz core performs metering math including RMS and harmonics without offloading. Industrial temperature rating meets utility outdoor cabinet specs. Pair with a Microchip ENC28J60 for Ethernet backhaul or MRF89XA for wireless mesh, both operating seamlessly from 5V rails.
Recommended
Point-of-Sale Terminal
The PIC18LF8680T-I/PT drives POS peripherals including 4x4 keypads, character LCDs, thermal printers, and magnetic-stripe readers through its 68 I/O. The 64 KB FLASH stores encrypted firmware, EMV kernels, and printer fonts. At 40 MHz the MCU handles USB enumeration, encryption acceleration via software library, and printer stepper control in parallel. Industrial temperature grade suits checkout-counter conditions including brief thermal excursions.
Recommended
Medical Monitoring Peripheral
The PIC18LF8680T-I/PT is appropriate for non-critical medical peripherals such as patient-bedside keypads, infusion-pump HMIs, and lab-instrument controllers where IEC 60601-1 isolation is handled externally. The 64 KB FLASH holds calibration tables, while the 10-bit ADC reads sensor bridges. Industrial temperature rating tolerates clinical environments. Not for life-support: select an AEC-Q100 or medical-grade MCU for direct patient contact devices per ISO 13485 workflows.
Recommended
Recommended Products Summary
Engineering reference data for PIC18LF8680T-I/PT — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC18LF8680-I/PT | PIC18LF8585-I/PT | PIC18LF6680T-I/PT | PIC18LF8525-I/PT | PIC18LF6722-I/PT |
|---|---|---|---|---|---|---|
| Package | TQFP-80 (12x12 mm) | TQFP-80 (12x12 mm) - same | TQFP-80 (12x12 mm) - same | TQFP-80 (12x12 mm) - same | TQFP-80 (12x12 mm) - same | TQFP-64 - smaller |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Core Frequency | 40 MHz (10 MIPS) | 40 MHz | 40 MHz | 40 MHz | 40 MHz | 40 MHz |
| FLASH Program Memory | 64 KB (32K x 16) | 64 KB | 48 KB | 64 KB | 48 KB | 128 KB |
| RAM | 3.25 KB (3328 B) | 3.25 KB | 3.25 KB | 3.25 KB | 3.25 KB | 3.25 KB |
| I/O Pins | 68 | 68 | 68 | 52 | 68 | 52 |
| Supply Voltage | 4.2 V to 5.5 V | 4.2 V to 5.5 V | 4.2 V to 5.5 V | 4.2 V to 5.5 V | 4.2 V to 5.5 V | 4.2 V to 5.5 V |
| Operating Temperature | -40C to +85C (Industrial) | -40C to +85C | -40C to +85C | -40C to +85C | -40C to +85C | -40C to +85C |
| Lead Free / RoHS | Yes | Yes | Yes | Yes | Yes | Yes |
Key Differentiators
- Highest I/O count in PIC18F TQFP-80 family (vs PIC18LF6680T-I/PT)
- Industrial temperature grade versus automotive-only competitors (vs PIC18F46K80T-I/PT (AEC-Q100))
- Self-programmable FLASH for in-application updates (vs PIC18LF6722-I/PT)
Design Notes
Place a 100 nF decoupling capacitor as close as possible to every VDD pin and pair each with a bulk 10 uF tantalum or ceramic at the board entry. The PIC18LF8680T-I/PT exposes multiple VDD/VSS pairs (pins 11/12, 41/42, 79/80) to manage simultaneous-switching noise from 68 I/O. A 1 uF to 4.7 uF bulk capacitor at the regulator output prevents inrush sag during flash programming. Total decoupling budget scales with the number of switching outputs - plan for ~30 mA per pin cluster during transitions.
The TQFP-80 (12x12 mm) package has theta_JA of approximately 50 C/W on a 4-layer JEDEC test board. At maximum ambient (85C industrial) and worst-case simultaneous I/O switching, the device can dissipate up to 1.3 W. Estimated: at 40 MHz core with all peripherals active, internal dissipation is typically 0.5-0.8 W, leaving thermal margin for industrial use. For sealed enclosures, derate to 70C ambient or add a copper flood beneath the exposed pad (the TQFP-80 has no EPAD, so spreader copper under the die is critical).
Route the MCLR pin with a 10 kohm pull-up to VDD and a 100 nF cap to VSS for clean reset transitions; an optional 1N4148 clamp diode protects against ESD on the reset line. Keep the oscillator traces short (<5 mm) and guard them with a ground ring to avoid coupling switching noise into the 40 MHz clock. Use a continuous ground plane beneath the TQFP-80 with at least 4 vias per quadrant to reduce thermal resistance and EMI. JTAG/ICD pins RB6/RB7 require series 100 ohm resistors when used for in-circuit debug.
Do not exceed VDD 5.5 V or the device may latch up; 4.2 V minimum is required at full 40 MHz operation below 5.0 V. Configuration bits (fuses) must be set explicitly - the default from Microchip may not match your application, especially the watchdog timer (WDT) and brown-out reset (BOR) thresholds. When migrating code from PIC16 to PIC18F, remember the 16-bit instruction word means program memory addresses are byte-doubled in the linker map. Always code-protect enabled for production builds to prevent firmware extraction.
Group GPIO by peripheral function on the schematic to simplify PCB routing - place all PSP/parallel data pins (RD0-RD7) on one bus-aligned edge, and isolate analog inputs (RA, RF) from digital switching lines with a ground moat. The PIC18LF8680T-I/PT has 68 user I/O which can route across 4-6 layers if not pre-planned. Reserve a 4-via ground pad beneath each I/O bank to handle simultaneous switching return currents. Crystal traces must reach within 1 mm of OSC1/OSC2 and never cross over a power plane discontinuity.
Compliance Information
RoHS compliant per DigiKey distributor listing and Microchip product page. Lead-free (matte tin) finish confirmed. AEC-Q100 not qualified - select automotive-grade parts from PIC18F46K80 family for under-hood designs. Halogen-free status not stated in distributor data; assume unknown.
