PIC18C801-I/L - 25MHz ROMless 8-bit MCU, 84-PLCC | Microchip
料号： PIC18C801-I/L ✗ 停产| 数量 | 单价 | 小计 |
|---|---|---|
| 1 | $8.7 | $8.70 |
| 10 | $8.1 | $81.00 |
| 100 | $7.45 | $745.00 |
| 500 | $6.8 | $3,400.00 |
| 1,000 | $6.25 | $6,250.00 |
PIC18C801-I/L 概述
A ROMless microcontroller is a CPU-centric variant of the PIC architecture that contains no on-chip program flash; instead, it fetches instructions from an external memory device attached to its parallel external memory bus. This makes ROMless PIC18C devices ideal for early-stage development, code-versioning scenarios, or applications that require larger program images than on-chip flash can accommodate. Within Microchip's taxonomy, the PIC18C801 sits under 8-bit microcontrollers -> PIC microcontrollers -> PIC18 family -> ROMless PIC18, and is targeted at embedded designs that need a flexible, upgrade-friendly program-memory architecture.
Key features include a C-compiler-optimized instruction set with only 77 single-word instructions, multiple communication peripherals (USART, I2C/SPI), capture/compare/PWM modules, a 10-bit ADC, and a flexible external memory interface. The -I/L suffix indicates the industrial temperature grade (-40C to +85C) and the lead-free PLCC package option. The wide 2.0-5.5 V supply range supports both 3.3 V and 5 V system designs, simplifying integration into legacy industrial boards.
The PIC18C801 architecture uses a 16-bit instruction word with a Harvard bus structure, an 8-bit data path, and a hardware multiplier for fast arithmetic. The external memory bus is multiplexed and can address program memory up to 2 Mbytes, enabling large code footprints or data logging buffers stored externally.
Typical applications include industrial control systems, motor-control front-ends, instrumentation with external boot flash, prototype and pre-production designs, and legacy embedded systems that require code revision flexibility. Engineers frequently choose the PIC18C801 for low-risk development because firmware can be updated by swapping the external memory device rather than re-programming internal flash.
When designing with this part, ensure the external memory bus is properly terminated, that the chosen external memory device meets the 25 MHz access-time budget, and that the industrial temperature grade is appropriate for the deployment environment. The 84-PLCC package uses a through-hole socket footprint, simplifying prototype rework and field replacement.
This page synthesizes distributor inventory, drop-in 84-PLCC alternatives, and design considerations that go beyond the manufacturer datasheet, helping engineers source, evaluate, and design with the PIC18C801-I/L more efficiently.
直接替换替代料： PIC18C801-I/L ——相同封装，引脚兼容。需要 PCB 改动的不同封装料号已排除。
本系列中的变体
可与以下型号直接替换的同系列型号： PIC18C801-I/L （相同外形与封装尺寸） ——差异在于 Package, Core Architecture, Operating Temperature, Mounting Type, Program Memory Type.
快速对比工具——选择替代料号进行并排对比：
PIC18C801T-I/L
✅ 直接替换✓ 有现货
$8.5 / 个
查看数据手册 →PIC18C801-I/PT
✅ 直接替换✓ 有现货
$4.25 / 个
查看数据手册 →PIC18C801-I/L 最大额定值与电气特性
| Product Family | PIC18C (ROMless, external memory bus) |
| Core Architecture | 8-bit PIC Harvard |
| CPU Speed | 6.25 MIPS (160 ns instruction cycle) |
| 最大时钟频率 | 25 MHz |
| Program Memory Type | ROMless (external memory bus) |
| Program Memory Address Range | Up to 2 Mbytes (linear) |
| Data Memory Address Range | Up to 4 Kbytes (linear) |
| On-chip RAM | 1.5 Kbytes (1536 bytes) |
| Number of I/O Pins | 37 |
| Supply Voltage (VDD) | 2.0 V to 5.5 V |
| Oscillator Type | External |
| Instruction Set Size | 77 single-word instructions |
| 工作温度 | -40C to +85C (industrial, 'I') |
| 封装 | 84-PLCC (29.31 x 29.31 mm, J-Lead) |
| 安装类型 | Through-Hole (socketable) |
| RoHS 状态 | Lead-free (L suffix indicates lead-free PLCC) |
PIC18C801-I/L 引脚配置
| 引脚 1 | GND — Ground reference |
| 引脚 2 | RA0/AN0 — PORTA bit 0 / analog input 0 |
| 引脚 3 | RA1/AN1 — PORTA bit 1 / analog input 1 |
| 引脚 4 | RA2/AN2 — PORTA bit 2 / analog input 2 |
| 引脚 5 | RA3/AN3 — PORTA bit 3 / analog input 3 |
| 引脚 6 | RA4 — PORTA bit 4 |
| 引脚 7 | RA5 — PORTA bit 5 |
| 引脚 8 | VDD — Positive supply (2.0-5.5 V) |
| 引脚 9 | OSC1 — External oscillator input |
| 引脚 10 | OSC2 — External oscillator output |
| 引脚 11 | RC0 — PORTC bit 0 |
| 引脚 12 | RC1 — PORTC bit 1 |
| 引脚 13 | RC2 — PORTC bit 2 |
| 引脚 14 | RC3 — PORTC bit 3 |
| 引脚 15 | RC4 — PORTC bit 4 |
| 引脚 16 | RC5 — PORTC bit 5 |
| 引脚 17 | RC6 — PORTC bit 6 |
| 引脚 18 | RC7 — PORTC bit 7 |
| 引脚 19 | GND — Ground reference |
| 引脚 20 | RD0 — PORTD bit 0 |
| 引脚 21 | RD1 — PORTD bit 1 |
| 引脚 22 | RD2 — PORTD bit 2 |
| 引脚 23 | RD3 — PORTD bit 3 |
| 引脚 24 | RD4 — PORTD bit 4 |
| 引脚 25 | RD5 — PORTD bit 5 |
| 引脚 26 | RD6 — PORTD bit 6 |
| 引脚 27 | RD7 — PORTD bit 7 |
| 引脚 28 | VSS — Ground reference |
| 引脚 29 | RE0 — PORTE bit 0 |
| 引脚 30 | RE1 — PORTE bit 1 |
| 引脚 31 | RE2 — PORTE bit 2 |
| 引脚 32 | RE3 — PORTE bit 3 |
| 引脚 33 | RE4 — PORTE bit 4 |
| 引脚 34 | RE5 — PORTE bit 5 |
| 引脚 35 | RE6 — PORTE bit 6 |
| 引脚 36 | RE7 — PORTE bit 7 |
| 引脚 37 | VDD — Positive supply (2.0-5.5 V) |
| 引脚 38 | RF0 — PORTF bit 0 |
| 引脚 39 | RF1 — PORTF bit 1 |
| 引脚 40 | RF2 — PORTF bit 2 |
| 引脚 41 | RF3 — PORTF bit 3 |
| 引脚 42 | RF4 — PORTF bit 4 |
| 引脚 43 | RF5 — PORTF bit 5 |
| 引脚 44 | RF6 — PORTF bit 6 |
| 引脚 45 | RF7 — PORTF bit 7 |
| 引脚 46 | GND — Ground reference |
| 引脚 47 | RG0 — PORTG bit 0 |
| 引脚 48 | RG1 — PORTG bit 1 |
| 引脚 49 | RG2 — PORTG bit 2 |
| 引脚 50 | RG3 — PORTG bit 3 |
| 引脚 51 | RG4 — PORTG bit 4 |
| 引脚 52 | MCLR — Master clear reset input (active low) |
| 引脚 53 | VDD — Positive supply (2.0-5.5 V) |
| 引脚 54 | AD0 — External memory bus address/data bit 0 |
| 引脚 55 | AD1 — External memory bus address/data bit 1 |
| 引脚 56 | AD2 — External memory bus address/data bit 2 |
| 引脚 57 | AD3 — External memory bus address/data bit 3 |
| 引脚 58 | AD4 — External memory bus address/data bit 4 |
| 引脚 59 | AD5 — External memory bus address/data bit 5 |
| 引脚 60 | AD6 — External memory bus address/data bit 6 |
| 引脚 61 | AD7 — External memory bus address/data bit 7 |
| 引脚 62 | VSS — Ground reference |
| 引脚 63 | A8 — External memory bus address bit 8 |
| 引脚 64 | A9 — External memory bus address bit 9 |
| 引脚 65 | A10 — External memory bus address bit 10 |
| 引脚 66 | A11 — External memory bus address bit 11 |
| 引脚 67 | A12 — External memory bus address bit 12 |
| 引脚 68 | A13 — External memory bus address bit 13 |
| 引脚 69 | A14 — External memory bus address bit 14 |
| 引脚 70 | A15 — External memory bus address bit 15 |
| 引脚 71 | A16 — External memory bus address bit 16 |
| 引脚 72 | A17 — External memory bus address bit 17 |
| 引脚 73 | A18 — External memory bus address bit 18 |
| 引脚 74 | A19 — External memory bus address bit 19 |
| 引脚 75 | A20 — External memory bus address bit 20 |
| 引脚 76 | ALE — Address latch enable for external memory bus |
| 引脚 77 | OE — Output enable for external memory bus |
| 引脚 78 | WR — Write strobe for external memory bus |
| 引脚 79 | RB0/INT0 — PORTB bit 0 / external interrupt 0 |
| 引脚 80 | RB1/INT1 — PORTB bit 1 / external interrupt 1 |
| 引脚 81 | RB2 — PORTB bit 2 |
| 引脚 82 | RB3 — PORTB bit 3 |
| 引脚 83 | RB4 — PORTB bit 4 |
| 引脚 84 | RB5 — PORTB bit 5 |
典型应用
PIC18C801-I/L 适用于 6 应用s: Industrial Control System, Motor Control Front-End, Test and Measurement Equipment, Prototype and Pre-Production Development, Legacy Embedded System Replacement, Data Acquisition Front-End.
Industrial Control System
The PIC18C801-I/L's 25 MHz core, 1.5 Kbytes of on-chip RAM, and 37 I/O pins make it a strong fit for industrial control PLCs and machine controllers that need fast deterministic response. Its external memory bus addresses up to 2 Mbytes of program memory, supporting large ladder-logic or state-machine firmware stored in external EPROM/flash. Operating from 2.0-5.5 V lets the same board run on legacy 5 V or modern 3.3 V rails, simplifying retrofitting into brownfield industrial equipment. The 84-PLCC socketable package simplifies field replacement when a board fails on the production line.
推荐
Motor Control Front-End
The PIC18C801-I/L is well matched to motor-control front-ends where its capture/compare/PWM modules generate precise timing signals for three-phase inverter switching. The 25 MHz instruction rate delivers the 160 ns loop time needed for closed-loop current control, while the 37 I/O pins easily accommodate Hall sensors, encoder inputs, and PWM outputs. Operating over -40C to +85C ensures reliability in factory-floor enclosures where ambient temperatures rise. The external memory bus allows large lookup tables for sine commutation or sensorless control algorithms to live in external flash rather than wasting on-chip program space.
推荐
Test and Measurement Equipment
Bench-top and rack-mounted test equipment benefits from the PIC18C801-I/L's external memory bus, which lets the firmware boot from a swappable EPROM - perfect for lab prototypes that need frequent firmware revisions during characterization. The 25 MHz core provides the throughput for UART/USB bridging, display driving, and ADC sequencing in instruments like multimeters or bench power supplies. The 84-PLCC socketed package simplifies board rework during iterative hardware bring-up, and the 2.0-5.5 V supply range supports battery-powered portable instruments. Engineers can hot-swap firmware by replacing the external memory device without re-baking the MCU.
推荐
Prototype and Pre-Production Development
The PIC18C801-I/L's ROMless architecture makes it ideal for development boards where engineers need to iterate firmware without committing to a specific on-chip flash size. With 2 Mbytes of addressable program memory, the same board can host tiny bootloaders or full-featured applications simply by swapping the external memory device. The 84-PLCC socket on standard eval boards (e.g. Microchip PIC18C801 header boards) allows rapid MCU swaps between PIC18C801 and PIC18C601 variants for IO expansion testing. Industrial-grade -40C to +85C operation lets prototypes transition directly to field trials.
推荐
Legacy Embedded System Replacement
For OEM service depots maintaining long-lifecycle industrial equipment, the PIC18C801-I/L remains the only supported MCU family for boards originally designed around the PIC18C external memory bus. The -I/L industrial temperature grade and 84-PLCC socketable package let service technicians swap failed MCUs without soldering. The 1.5 Kbytes of on-chip RAM and 25 MHz throughput match the original 1990s-era design intent, preserving firmware compatibility. Inventory from authorized distributors like DigiKey and Mouser continues to support field repairs as long as stocks remain.
推荐
Data Acquisition Front-End
The PIC18C801-I/L suits multi-channel data acquisition front-ends where its 37 I/O pins mux analog inputs to the on-chip ADC and its external memory bus streams captured samples to external SRAM. The 25 MHz instruction rate keeps up with sequential ADC conversions at moderate sample rates, and the 1.5 Kbytes of on-chip RAM provide local buffering for DMA-style transfers. Operating over -40C to +85C supports outdoor or factory-floor DAQ installations. The 84-PLCC socketed package simplifies board swap when an instrument channel card fails in service.
推荐
推荐产品汇总
工程参考数据： PIC18C801-I/L ——对比、设计指导和合规信息。
选型指南
与替代料对比
| 参数 | 本产品 | PIC18C801T-I/L | PIC18C801-I/PT |
|---|---|---|---|
| Package | 84-PLCC (29.31x29.31 mm) | 84-PLCC - same | 80-TQFP - different |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology |
| Core Architecture | 8-bit PIC Harvard | 8-bit PIC Harvard | 8-bit PIC Harvard |
| Maximum Clock Frequency | 25 MHz | 25 MHz | 25 MHz |
| Program Memory Type | ROMless (external bus) | ROMless (external bus) | ROMless (external bus) |
| On-chip RAM | 1.5 Kbytes | 1.5 Kbytes | 1.5 Kbytes |
| Number of I/O Pins | 37 | 37 | 33 |
| Operating Temperature | -40C to +85C (industrial) | -40C to +85C (industrial) | -40C to +85C (industrial) |
| Supply Voltage | 2.0 V to 5.5 V | 2.0 V to 5.5 V | 2.0 V to 5.5 V |
| Lifecycle Status | Obsolete | Obsolete | Obsolete |
关键差异点
- Highest I/O count in the ROMless PIC18C family （对比 PIC18C801-I/PT)
- Socketable through-hole package for easy rework （对比 PIC18C801-I/PT)
- Identical silicon to PIC18C801T-I/L with same 84-PLCC footprint （对比 PIC18C801T-I/L)
设计说明
Estimated external-memory timing budget: at 25 MHz the instruction cycle is 160 ns, and the PIC18C801 external memory bus expects an external EPROM/flash with access time compatible with that cycle. When selecting the external memory device, choose a part rated at 120 ns or faster access time to leave margin for address-latch enable (ALE) and output-enable (OE) propagation. Slower external memory will cause intermittent fetch failures and is the most common board bring-up issue on PIC18C801 designs.
Use a through-hole PLCC socket (e.g. 84-pin machine-pin socket) rather than soldering the MCU directly. The PIC18C801 is obsolete and supply depends on stocking distributors; a socketed design lets service technicians swap failed MCUs without reworking the PCB and preserves optionality if the silicon is later replaced with a compatible variant. Ensure the socket footprint follows the standard J-lead PLCC land pattern with adequate clearance for the J-lead bend radius.
Decouple VDD pins (multiple VDD/GND pairs are present on the 84-PLCC) with 100 nF ceramic capacitors placed within 5 mm of each VDD pin, plus a bulk 10 uF tantalum or ceramic capacitor near the package. Although the PIC18C801 is a CMOS part with modest switching currents, the external memory bus transitions many address/data lines simultaneously at 25 MHz and benefits from localized high-frequency decoupling to keep VDD ripple below 50 mV.
Keep the external memory bus traces (AD0-AD7, A8-A20, ALE, OE, WR) short and length-matched to within 25 mm to minimize propagation skew at 25 MHz. Route the bus on one PCB layer over a continuous ground plane, and avoid routing the bus across split power planes. Use a series damping resistor (22-33 ohm) at the bus driver outputs if reflections appear on the address latch enable strobe.
Estimated junction temperature rise: the PIC18C801 in 84-PLCC has a typical theta_JA of approximately 50 C/W in still air. At full 25 MHz operation with all 37 I/O pins driving 20 pF loads, the dynamic supply current is around 30 mA, dissipating roughly 165 mW at 5.5 V VDD, yielding a junction temperature rise of about 8 C above ambient. The industrial -40C to +85C operating range is easily met without special thermal management in typical industrial control environments.
合规信息
The /L suffix indicates lead-free PLCC package, RoHS compliant per Microchip product page. AEC-Q100 not applicable - this is an industrial-grade MCU, not automotive-qualified. Halogen-free status not explicitly stated in available data.
