PIC18C801-I/PT - 8-bit ROMless MCU, 2MB External Bus, TQFP-80 | Microchip
MPN: PIC18C801-I/PT ✗ End of Life| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $7.2 | $7.20 |
| 10 | $6.55 | $65.50 |
| 100 | $5.4 | $540.00 |
| 500 | $4.85 | $2,425.00 |
| 1,000 | $4.25 | $4,250.00 |
PIC18C801-I/PT Overview
A microcontroller (MCU) is a single-chip computer that integrates a CPU core, program memory, working RAM, and a range of peripherals (timers, ADC, communication ports) into one package. Within the broader semiconductor taxonomy, the PIC18C801 sits at: microcontroller -> embedded microcontroller -> 8-bit RISC MCU -> semiconductor device. The 8-bit class remains widely deployed in cost-sensitive, deterministic-control applications where 32-bit performance is unnecessary and where the C-friendly PIC18 instruction set with only 77 single-word instructions reduces firmware complexity.
Key features include operation from a 5V supply, an external oscillator interface, industrial temperature grade (-40C to +85C), and ROMless operation that lets the designer pair the MCU with external program memory (EPROM/Flash) for prototyping or low-volume manufacturing. The 12-channel 10-bit ADC supports sensor interfacing, while the two CCP modules provide PWM for motor control, lighting, and power-conversion feedback loops. The ROMless architecture is ideal for systems that require large external program storage, code-update flexibility, or where in-system reprogrammability is mandated.
Typical applications include industrial automation controllers, motor-control boards, sensor-interface front ends, and educational/development platforms that emulate PIC18C601 behavior with larger code space. Designers also use this part for legacy industrial systems where firmware has been validated on the PIC18C601 and now needs additional code headroom.
When designing with the PIC18C801, allocate a generous PCB footprint for the 80-pin TQFP and route the external memory bus with attention to signal integrity. The ROMless architecture adds latency on external fetches compared to flash-based PICs, so critical interrupt routines must be kept short. Use the CCP modules for time-critical control loops.
This page synthesizes verified distributor pricing, drop-in compatible TQFP-80 alternatives, application examples, and design notes not consolidated in the manufacturer datasheet alone.
Drop-in alternatives for PIC18C801-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 PIC18C801-I/PT (same form factor and footprint) — differing in Package, Program Memory Type, Operating Temperature, Core Architecture, Program Memory Size.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC18C601-I/PT
✅ Drop-In✓ In Stock
$6.08 / Unit
View Datasheet →PIC18C658T-I/PT
✅ Drop-In ⚠️ Specs Unverified✓ In Stock
$6.85 / Unit
View Datasheet →PIC18C452T-I/L
✅ Drop-In ⚠️ Specs Unverified✓ In Stock
$5.75 / Unit
View Datasheet →PIC18C801-I/PT Maximum Ratings & Electrical Characteristics
| Core Architecture | PIC18 (Harvard, 8-bit RISC) |
| Program Memory Type | ROMless (external memory interface) |
| External Memory Address Space | 2 MB |
| Instruction Set Size | 77 single-word instructions |
| Instruction Execution Time | 160 ns (at 25 MHz, 6.25 MIPS) |
| Maximum CPU Clock | 25 MHz |
| On-chip RAM | 1.5 KB (1536 bytes) |
| Digital I/O Pins | 37 |
| ADC | 12 channels, 10-bit resolution |
| Capture/Compare/PWM Modules | 2 |
| Serial Interfaces | 1x SSP (SPI or I2C configurable) |
| Supply Voltage | 5 V |
| Oscillator Type | External |
| Operating Temperature | -40C to +85C (industrial grade) |
| Package | TQFP-80 (PT) |
| Mounting Type | Surface Mount |
| Lead-Free / RoHS | Depends on date code - check lot markings |
| Pin/Package Compatibility | Upward compatible with PIC16C5X, PIC12CXXX families (architectural, not pin-to-pin) |
PIC18C801-I/PT Pin Configuration
| Pin 1 | MCLR — Master clear (reset) input |
| Pin 2 | OSC1 — External oscillator input |
| Pin 3 | OSC2 — External oscillator output |
| Pin 4 | RA0/AN0 — PORTA bit 0 / ADC channel 0 |
| Pin 5 | RA1/AN1 — PORTA bit 1 / ADC channel 1 |
| Pin 6 | RA2/AN2 — PORTA bit 2 / ADC channel 2 |
| Pin 7 | RA3/AN3/VREF+ — PORTA bit 3 / ADC channel 3 / ADC VREF+ |
| Pin 8 | RA4/AN4 — PORTA bit 4 / ADC channel 4 |
| Pin 9 | RA5/AN5 — PORTA bit 5 / ADC channel 5 |
| Pin 10 | VSS — Ground |
| Pin 11 | VDD — Positive supply (5V) |
| Pin 12 | RB0/INT0 — PORTB bit 0 / external interrupt 0 |
| Pin 13 | RB1/INT1 — PORTB bit 1 / external interrupt 1 |
| Pin 14 | RB2/INT2 — PORTB bit 2 / external interrupt 2 |
| Pin 15 | RB3/CCP2 — PORTB bit 3 / CCP2 I/O |
| Pin 16 | RB4 — PORTB bit 4 |
| Pin 17 | RB5 — PORTB bit 5 |
| Pin 18 | RB6/PGC — PORTB bit 6 / ICSP clock |
| Pin 19 | RB7/PGD — PORTB bit 7 / ICSP data |
| Pin 20 | VSS — Ground |
| Pin 21 | VDD — Positive supply (5V) |
| Pin 22 | RC0/T1OSO — PORTC bit 0 / Timer1 oscillator output |
| Pin 23 | RC1/T1OSI — PORTC bit 1 / Timer1 oscillator input |
| Pin 24 | RC2/CCP1 — PORTC bit 2 / CCP1 I/O |
| Pin 25 | RC3/SCK/SCL — PORTC bit 3 / SPI clock / I2C clock |
| Pin 26 | RC4/SDI/SDA — PORTC bit 4 / SPI data in / I2C data |
| Pin 27 | RC5/SDO — PORTC bit 5 / SPI data out |
| Pin 28 | RC6/TX — PORTC bit 6 / USART transmit |
| Pin 29 | RC7/RX — PORTC bit 7 / USART receive |
| Pin 30 | RD0/AD0 — PORTD bit 0 / external memory address/data bit 0 |
| Pin 31 | RD1/AD1 — PORTD bit 1 / external memory address/data bit 1 |
| Pin 32 | RD2/AD2 — PORTD bit 2 / external memory address/data bit 2 |
| Pin 33 | RD3/AD3 — PORTD bit 3 / external memory address/data bit 3 |
| Pin 34 | RD4/AD4 — PORTD bit 4 / external memory address/data bit 4 |
| Pin 35 | RD5/AD5 — PORTD bit 5 / external memory address/data bit 5 |
| Pin 36 | RD6/AD6 — PORTD bit 6 / external memory address/data bit 6 |
| Pin 37 | RD7/AD7 — PORTD bit 7 / external memory address/data bit 7 |
| Pin 38 | VSS — Ground |
| Pin 39 | VDD — Positive supply (5V) |
| Pin 40 | RE0/AD8 — PORTE bit 0 / external memory address bit 8 |
| Pin 41 | RE1/AD9 — PORTE bit 1 / external memory address bit 9 |
| Pin 42 | RE2/AD10 — PORTE bit 2 / external memory address bit 10 |
| Pin 43 | RE3/AD11 — PORTE bit 3 / external memory address bit 11 |
| Pin 44 | RE4/AD12 — PORTE bit 4 / external memory address bit 12 |
| Pin 45 | RE5/AD13 — PORTE bit 5 / external memory address bit 13 |
| Pin 46 | RE6/AD14 — PORTE bit 6 / external memory address bit 14 |
| Pin 47 | RE7/AD15 — PORTE bit 7 / external memory address bit 15 |
| Pin 48 | VSS — Ground |
| Pin 49 | VDD — Positive supply (5V) |
| Pin 50 | RF0/AD16 — PORTF bit 0 / external memory address bit 16 |
| Pin 51 | RF1/AD17 — PORTF bit 1 / external memory address bit 17 |
| Pin 52 | RF2/AD18 — PORTF bit 2 / external memory address bit 18 |
| Pin 53 | RF3/AD19 — PORTF bit 3 / external memory address bit 19 |
| Pin 54 | RF4/AD20 — PORTF bit 4 / external memory address bit 20 |
| Pin 55 | RF5/AN6 — PORTF bit 5 / ADC channel 6 |
| Pin 56 | RF6/AN7 — PORTF bit 6 / ADC channel 7 |
| Pin 57 | RF7/AN8 — PORTF bit 7 / ADC channel 8 |
| Pin 58 | VSS — Ground |
| Pin 59 | VDD — Positive supply (5V) |
| Pin 60 | RG0 — PORTG bit 0 |
| Pin 61 | RG1 — PORTG bit 1 |
| Pin 62 | RG2 — PORTG bit 2 |
| Pin 63 | RG3 — PORTG bit 3 |
| Pin 64 | RG4 — PORTG bit 4 |
| Pin 65 | RG5 — PORTG bit 5 |
| Pin 66 | RG6 — PORTG bit 6 |
| Pin 67 | RG7 — PORTG bit 7 |
| Pin 68 | AVSS — Analog ground |
| Pin 69 | AVDD — Analog supply (5V) |
| Pin 70 | RH0/A16 — PORTH bit 0 / external memory address bit (high) |
| Pin 71 | RH1/A17 — PORTH bit 1 / external memory address bit (high) |
| Pin 72 | RH2/A18 — PORTH bit 2 / external memory address bit (high) |
| Pin 73 | RH3/A19 — PORTH bit 3 / external memory address bit (high) |
| Pin 74 | RH4 — PORTH bit 4 |
| Pin 75 | RH5 — PORTH bit 5 |
| Pin 76 | RH6 — PORTH bit 6 |
| Pin 77 | RH7 — PORTH bit 7 |
| Pin 78 | RJ0 — PORTJ bit 0 |
| Pin 79 | RJ1 — PORTJ bit 1 |
| Pin 80 | VSS — Ground |
Typical Applications
PIC18C801-I/PT is suitable for 6 applications: Industrial Automation Controllers, Motor Control Boards, Sensor Interface Front Ends, Educational and Development Platforms, Legacy Industrial System Sustaining Engineering, Display and Human-Machine Interface Modules.
Industrial Automation Controllers
The PIC18C801-I/PT suits industrial automation controllers that need deterministic 8-bit processing, a large external code space for complex ladder-logic-equivalent state machines, and robust 5V I/O. Its 37 digital I/O pins drive relays, optocouplers, and discrete sensors directly, while the 12-channel 10-bit ADC reads analog process variables (temperature, pressure, flow). The 2 MB external memory bus accommodates large protocol stacks (Modbus RTU, custom fieldbus) and lookup tables for PID tuning. Unlike flash-based PIC18F parts, the ROMless architecture lets field engineers update firmware via external Flash without in-circuit programming, simplifying field servicing. Two CCP modules provide PWM for proportional valve control, and the SPI/I2C port interfaces to digital sensors and expansion I/O. Pin-compatible with PIC18C601 for code under 128 KB.
Recommended
Motor Control Boards
The PIC18C801-I/PT drives BLDC, stepper, and DC motor control boards via its two CCP modules generating 10-bit PWM at up to 25 MHz instruction rate. The 37 I/O pins support H-bridge gate drivers, Hall-sensor feedback, encoder inputs, and fault monitoring, while the 12-channel 10-bit ADC samples motor current, back-EMF, and temperature for closed-loop control. The 6.25 MIPS performance is sufficient for trapezoidal and sensorless commutation algorithms. The ROMless architecture enables field firmware updates via external Flash, valuable for tuning motor profiles without IC replacement. Industrial temperature grade (-40C to +85C) tolerates under-hood environments. Companion gate drivers and op-amps complete the analog signal chain.
Recommended
Sensor Interface Front Ends
The PIC18C801-I/PT serves as a multi-channel sensor interface front end, with its 12-channel 10-bit ADC scanning analog sensors at rates up to ~50 ksps, and 37 I/O lines for digital sensor interfacing and bus arbitration. The 1.5 KB on-chip RAM holds scan buffers and calibration coefficients, while the 2 MB external memory bus stores sensor linearization tables and lookup data. SPI/I2C peripherals connect to digital temperature sensors, accelerometers, and expansion I/O expanders. Industrial-grade temperature operation allows deployment in harsh factory and outdoor environments. The ROMless design enables last-minute calibration data updates without scrapping programmed parts.
Recommended
Educational and Development Platforms
The PIC18C801-I/PT is widely used in university and training labs as a teaching vehicle for the PIC18 Harvard architecture, because its ROMless design exposes the external memory bus - a topic increasingly omitted from flash-based MCU curricula. Students learn bus timing, wait-state insertion, and memory-mapped peripheral design directly. The 80-pin TQFP package accommodates breadboard-adapter PCBs, and the 5V supply is forgiving for lab power. The 25 MHz instruction rate keeps cycle-accurate exercises realistic. Pairing the device with an external EPROM or Flash socket lets students re-program without IC erasing. Source code libraries and reference designs are widely available from Microchip's application notes.
Recommended
Legacy Industrial System Sustaining Engineering
The PIC18C801-I/PT remains the firmware baseline for installed industrial controllers, sustaining-engineering programs, and spare-parts manufacturing where the validated firmware binary must run on identical silicon. Its ROMless architecture lets sustain engineers patch code via external Flash swap without re-programming the MCU, preserving test traceability. The 80-pin TQFP remains compatible with original PCBs, and 5V I/O matches older analog front ends. The PIC18C601-I/PT is a true drop-in for firmware under 128 KB. Long-term production engineers transition designs to PIC18F8722-I/PT (flash-based, same TQFP-80 family) for new builds, while continuing PIC18C801 production for spare-parts orders.
Recommended
Display and Human-Machine Interface Modules
The PIC18C801-I/PT drives small character LCDs, LED matrix panels, and key-scan interfaces for HMI modules in industrial and appliance settings. The 37 I/O pins handle 4-bit or 8-bit LCD data buses, LED row/column drivers, and matrix keypads without external logic. The 6.25 MIPS instruction rate supports multi-tasking menu rendering and debounce logic. The 1.5 KB RAM buffers display strings and key events, and the 2 MB external memory bus holds international character tables and multilingual message strings. The SPI/I2C peripheral expands to additional key/LED driver chips for larger panels.
Recommended
Recommended Products Summary
Engineering reference data for PIC18C801-I/PT — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC18C601-I/PT | PIC18C658T-I/PT | PIC18C452T-I/L |
|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | TQFP-80 (PT) | TQFP-80 (PT) - same | TQFP-80 (PT) - same | TQFP-80 (PT/L) - same |
| Program Memory | ROMless (external bus, 2 MB addressable) | ROMless (external bus, 128 KB) | On-chip OTP (~32 KB) + external (64 KB) | On-chip OTP (32 KB), no external bus |
| External Memory Bus | Yes, 2 MB addressable | Yes, 128 KB | Yes, 64 KB | No |
| On-chip RAM | 1.5 KB | 1.5 KB | 1.5 KB | 1.5 KB |
| Max CPU Clock | 25 MHz (6.25 MIPS) | 25 MHz | 40 MHz | 40 MHz |
| ADC Channels | 12 x 10-bit | 12 x 10-bit | 12 x 10-bit | 8 x 10-bit |
| CCP Modules | 2 | 2 | 2 | 2 |
| CAN Module | No | No | Yes | No |
| Lifecycle Status | Obsolete | Obsolete | Obsolete | Obsolete |
Key Differentiators
- Largest external code space in PIC18 family (vs PIC18C601-I/PT)
- On-chip CAN module and OTP program memory (vs PIC18C452T-I/L)
- Higher instruction rate than PIC18C452 (vs PIC18C452T-I/L)
Design Notes
The TQFP-80 (PT) package requires a PCB land pattern with 0.50 mm pitch and an exposed thermal pad is not present - ground is supplied via multiple VSS pins (10, 20, 38, 48, 58, 80). Decouple each VDD pin with a 100 nF ceramic capacitor placed within 5 mm of the pin, and add a bulk 10 uF tantalum or ceramic capacitor per VDD pair. The external memory bus signals (PORTD/AD0-AD7, PORTE/AD8-AD15, PORTF/AD16-AD20, PORTH) should be routed with matched lengths and series damping resistors near the MCU to suppress ringing on the parallel bus edges.
The external memory bus operates at the full oscillator rate; with a 25 MHz oscillator the address/data lines toggle in <40 ns. Route AD0-AD15 on an inner PCB layer with a continuous ground plane below, keep trace lengths under 50 mm, and place 33 ohm series resistors at the MCU outputs to damp reflections. The external bus is also shared with the digital I/O functions on PORTD/PORTE/PORTF/PORTH, so write to the LATx registers rather than PORTx to avoid read-modify-write hazards when toggling bus pins during external cycles.
Configuration word settings must be reviewed carefully for the PIC18C801; the watchdog timer, low-voltage programming, and oscillator modes are set in the config word and are not re-readable by firmware. Designers moving code from PIC18C601 to PIC18C801 must verify the bus configuration register enables the extended 2 MB address mode (PIC18C801 only) - on PIC18C601 the upper address bits are remapped. The ROMless design requires an external program memory device (EPROM/Flash) at the bus base; missing memory yields garbage execution.
Compliance Information
Compliance status varies by date code; obsolete parts often ship from older lots. Verify RoHS/lead-free status with the specific supplier and Microchip's date-code marking. Part is industrial-grade (-40C to +85C) but not AEC-Q100 qualified for automotive use.
