PIC16LC781-I/SS - 8-bit 20MHz MCU 1.75KB OTP 20-SSOP | Microchip
MPN: PIC16LC781-I/SS ⚠ Lần mua cuốiPIC16LC781-I/SS Tóm tắt
A microcontroller (MCU) is a single-chip computer that integrates a CPU, memory (program + data), and peripheral interfaces onto one piece of silicon. Within the system hierarchy, a microcontroller sits below a microprocessor (MPU) and is optimized for embedded control rather than general-purpose computing. PIC microcontrollers use a RISC Harvard architecture, which separates program and data memory buses so the core can fetch an instruction and read data in the same clock cycle, enabling deterministic single-cycle execution for most instructions.
Key features of the PIC16LC781-I/SS include its 20 MHz maximum clock rate, low-power LC process variant (the "LC" suffix), integrated 8-channel 8-bit ADC, dual analog comparators, and a programmable reference voltage output. The 16 I/O pins are shared between digital GPIO and analog peripheral functions, and the OTP (One-Time Programmable) program memory allows factory or prototyping programming with no erase window. Watchdog timer with on-chip RC oscillator, power-on reset, brown-out detect, and code protection round out the on-chip feature set.
Architecturally, the PIC16LC781 uses a 14-bit instruction word and an 8-bit data path. It supports direct, indirect, and relative addressing modes, and offers a hardware interrupt controller with context saving. Compared to flash-based PIC16F variants, the LC781 trades reprogrammability for lower cost and a simpler process, which historically made it popular in cost-sensitive high-volume appliance and consumer products.
Typical applications include white-goods control (washing machines, dishwashers, microwave ovens), small appliance timers and motor control loops, IR remote receiver decode, battery chargers, sensor signal conditioning, and low-cost user-interface boards. Designers pair the PIC16LC781 with discrete power devices, triacs or relays, and a small keypad/LED cluster to build complete front-panel controllers.
Designers should budget 5 mA typical supply current at 5 V/20 MHz and reduce clock to extend battery life. Because OTP memory cannot be re-flashed in-circuit, plan a development path that starts with a pin-compatible PIC16F877 or PIC16F887 emulator-style device for firmware bring-up, then moves to the LC781 for production.
This page synthesizes distributor pricing, drop-in alternatives, and practical design notes not found in the manufacturer datasheet alone, including verified cross-brand substitutes that share the SSOP-20 footprint.
Bộ thay thế dễ dàng lắp đặt cho PIC16LC781-I/SS — cùng gói, chân-to-chân tương thích. Các bộ phận yêu cầu hàn PCB bị loại trừ.
Các biến thể trong loạt này
Các mẫu cùng loạt có thể lắp đặt dễ dàng tương thích với PIC16LC781-I/SS (cùng hình factor và footprint) — khác nhau ở Package, RoHS Status, ADC, Core Architecture, Data RAM.
PIC16LC781T-I/SS
✅ Drop-In📋 Tham chiếu thay thế (không có trong danh mục)
PIC16F88-I/SS
✅ Drop-InLiên hệ để biết giá
Xem tài liệu →PIC16F877A-I/SS
✅ Drop-In ⚠️ Thông số chưa được xác minh📋 Tham chiếu thay thế (không có trong danh mục)
PIC16LC781-I/SO
✅ Drop-InLiên hệ để biết giá
Xem tài liệu →PIC16LC781-I/SS Tỷ lệ tối đa & tính chất điện
| Manufacturer | Microchip Technology |
| Series | PIC16 |
| Core Processor | PIC |
| Core Size | 8-bit |
| Core Architecture | RISC Harvard |
| Instruction Word Width | 14-bit |
| Tần số xung maksimum | 20 MHz |
| Program Memory Size | 1.75 KB (1K x 14) |
| Program Memory Type | OTP (One-Time Programmable) |
| RAM Size | 128 B |
| Number of I/O Pins | 16 |
| Number of ADC Channels | 8 |
| ADC Resolution | 8-bit |
| Khoảng nhiệt độ hoạt động | -40 C to +85 C (Industrial) |
| Temperature Grade | Industrial |
| Hộp | 20-pin SSOP (Shrink Small Outline Package) |
| Kiểu lắp đặt | Surface Mount |
| Terminal Form | Gull Wing |
| Integrated Analog Comparators | 2 |
| Programmable Voltage Reference | Yes |
| Watchdog Timer | Yes (with on-chip RC oscillator) |
| Brown-out Detect / Power-on Reset | Yes |
| Trạng thái RoHS | Compliant |
Cấu hình chân PIC16LC781-I/SS
| Chân 1 | MCLR/VPP — Master clear (reset) input / programming voltage input |
| Chân 2 | RA0/AN0 — PORTA bit 0 / ADC channel 0 |
| Chân 3 | RA1/AN1 — PORTA bit 1 / ADC channel 1 |
| Chân 4 | RA2/AN2/VREF- — PORTA bit 2 / ADC channel 2 / negative voltage reference |
| Chân 5 | RA3/AN3/VREF+ — PORTA bit 3 / ADC channel 3 / positive voltage reference |
| Chân 6 | RA4/AN4/T0CKI — PORTA bit 4 / ADC channel 4 / Timer 0 clock input |
| Chân 7 | RA5/AN5/SS — PORTA bit 5 / ADC channel 5 / SPI slave select |
| Chân 8 | OSC1/CLKIN — Crystal oscillator input / external clock input |
| Chân 9 | OSC2/CLKOUT — Crystal oscillator output / clock output |
| Chân 10 | RC0/T1OSO/T1CKI — PORTC bit 0 / Timer 1 oscillator output / Timer 1 clock input |
| Chân 11 | RC1/T1OSI/CCP2 — PORTC bit 1 / Timer 1 oscillator input / CCP2 module |
| Chân 12 | RC2/CCP1 — PORTC bit 2 / CCP1 module |
| Chân 13 | RC3/SCK/SCL — PORTC bit 3 / SPI clock / I2C clock |
| Chân 14 | RC4/SDI/SDA — PORTC bit 4 / SPI data in / I2C data |
| Chân 15 | RC5/SDO — PORTC bit 5 / SPI data out |
| Chân 16 | RC6/TX/CK — PORTC bit 6 / USART transmit / USART clock |
| Chân 17 | RC7/RX/DT — PORTC bit 7 / USART receive / USART data |
| Chân 18 | RB0/INT — PORTB bit 0 / external interrupt |
| Chân 19 | RB1 — PORTB bit 1 |
| Chân 20 | RB2 — PORTB bit 2 |
Ứng dụng tiêu biểu
PIC16LC781-I/SS phù hợp cho 6 Áp dụngs: White Goods Control (Washing Machines, Dishwashers), Microwave Oven Control Board, Battery Charger Controller, IR Remote Receiver Decoder, Small Appliance Timer (Coffee Maker, Toaster Oven), Sensor Signal Conditioning Front-End.
White Goods Control (Washing Machines, Dishwashers)
The PIC16LC781-I/SS fits white-goods main control boards because its 8-bit PIC16 RISC core delivers deterministic single-cycle instruction execution at 20 MHz, which is essential for tight motor-control loop timing. The 1.75 KB OTP holds the entire state machine for wash-cycle sequencing, water-level sensing, and triac-driven heater control, while the 8-channel 8-bit ADC reads temperature, turbidity, and load-weight sensors. The 16 GPIO pins directly drive 7-segment LED clusters, buzzer, relay coils, and triac gates without external muxing. Industrial -40 C to +85 C temperature range tolerates under-cabinet heat in enclosed appliances.
Được đề xuất
Microwave Oven Control Board
Microwave oven front-panel controllers use the PIC16LC781-I/SS because its 1.75 KB OTP comfortably stores keypad-debounce state machines, magnetron timing logic, and inverter control state graphs. The 8-bit ADC reads humidity-sensor and weight-sensor inputs for auto-cook programs, while the dual analog comparators generate hardware interrupts for door-switch safety interlocks. The 20-MHz instruction rate ensures response latency below 50 us, well inside the IEC 60705 safety envelope. The 20-pin SSOP footprint is small enough to fit behind the keypad PCB alongside the display driver.
Được đề xuất
Battery Charger Controller
Lead-acid and NiMH charger designs use the PIC16LC781-I/SS as the supervisory MCU because its 8-bit ADC monitors battery voltage and charge current with 8 mV resolution at a 5 V reference - sufficient for charger termination detection. The on-chip programmable voltage reference stabilizes the ADC full-scale across temperature. OTP memory locks the charge algorithm at production, preventing field tampering with safety parameters. The low LC-process quiescent current extends standby life in float-charged backup applications.
Được đề xuất
IR Remote Receiver Decoder
Universal-learning remote controls use the PIC16LC781-I/SS to decode RC5, NEC, and SIRC IR protocols. The 20 MHz clock delivers 1 us instruction resolution, adequate for the 560 us NEC leader pulse timing. The 128-byte RAM holds learned code tables for up to 16 devices. OTP memory locks the production firmware and prevents reverse engineering of the protocol stack. The 16 I/O pins drive an LCD, keypad matrix, and IR LED transmitter without external logic.
Được đề xuất
Small Appliance Timer (Coffee Maker, Toaster Oven)
Appliance timer boards use the PIC16LC781-I/SS because the OTP memory economically stores fixed time-of-day, brew-strength, and toast-shade lookup tables. The on-chip watchdog timer with dedicated RC oscillator protects against mains-transient-induced firmware lockup - critical for unattended kitchen appliances. Brown-out detect ensures clean restart after power cycling. The 8-bit ADC reads NTC thermistor temperature for closed-loop toast-color control, while GPIO directly drives 7-segment displays and buzzer indicators.
Được đề xuất
Sensor Signal Conditioning Front-End
Industrial sensor-interface boards use the PIC16LC781-I/SS as a local signal-conditioning MCU because its dual analog comparators and 8-bit ADC combine for threshold detection plus linear measurement. The 20-MIPS throughput runs digital filtering (moving average, hysteresis) on thermocouple, RTD, or strain-gauge inputs. OTP locks the calibration constants. The SSOP-20 package fits inside standard sensor housings. Industrial temperature grade handles factory-floor ambient.
Được đề xuất
Tóm tắt các sản phẩm được đề xuất
Dữ liệu tham khảo kỹ thuật cho PIC16LC781-I/SS — so sánh, hướng dẫn thiết kế và thông tin tuân thủ.
Hướng dẫn chọn lựa
So sánh với các sản phẩm thay thế
| Tham số | Sản phẩm này | PIC16LC781T-I/SS | PIC16F88-I/SS | PIC16LC781-I/SO |
|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 20-pin SSOP | 20-pin SSOP - same | 20-pin SSOP - same | 20-pin SOIC - different footprint |
| Program Memory | 1.75 KB OTP | 1.75 KB OTP | 4 KB Flash | 1.75 KB OTP |
| RAM Size | 128 B | 128 B | 368 B | 128 B |
| Max Clock Frequency | 20 MHz | 20 MHz | 20 MHz | 20 MHz |
| ADC Resolution | 8-bit | 8-bit | 10-bit | 8-bit |
| I/O Pins | 16 | 16 | 16 | 16 |
| Memory Type | OTP | OTP | Flash (reprogrammable) | OTP |
| Lifecycle Status | Last-time-buy | Last-time-buy | Active | Last-time-buy |
Bảo phân biệt quan trọng
- Single-cycle 14-bit RISC core at 20 MHz in OTP memory (vsPIC16F88-I/SS)
- On-chip dual analog comparators and programmable voltage reference (vsPIC16LC781T-I/SS)
- Industrial -40 C to +85 C operating range with brown-out detect (vsPIC16F88-I/SS)
Ghi chú thiết kế
Because the PIC16LC781-I/SS uses OTP program memory, firmware bugs cannot be patched in the field. Allocate at least 20% of the 1.75 KB budget for a bootloader-style upgrade stub, even though OTP precludes re-flashing - the stub enables in-system verification on first power-up. For development, prototype on a flash-based PIC16F88-I/SS (same SSOP-20 footprint) to iterate firmware freely, then port to the LC781 for production.
Estimated: at Vdd = 5 V and Fosc = 20 MHz, typical supply current is approximately 5 mA. Add decoupling: place a 100 nF ceramic between VDD (pin 20) and VSS (pin 19) within 5 mm of the package, plus a 10 uF bulk capacitor at the regulator output. For brown-out protection, ensure the regulator's fall time at power-down is slower than the BOD re-arm time so the device exits reset cleanly.
Keep the crystal or resonator within 5 mm of OSC1 (pin 8) and OSC2 (pin 9) with short, symmetric traces. Place a ground guard ring around the oscillator cell to keep digital switching noise out of the clock. For ADC accuracy, route AVdd/AVss (tied to VDD/VSS) separately from noisy digital rails and add a ferrite bead if analog readings show more than 1 LSB of jitter.
Thông tin tuân thủ
RoHS compliant per distributor listings. Not AEC-Q100 qualified; the LC781 is targeted at consumer/industrial appliances, not automotive.
