PIC16C74A-20/PT - 8-Bit 20MHz OTP MCU 7KB Flash 44-TQFP | Microchip
MPN: PIC16C74A-20/PT ⚠ Lần mua cuốiPIC16C74A-20/PT Tóm tắt
Background - what is an OTP PIC16C microcontroller. An 8-bit OTP microcontroller is a Harvard-architecture CMOS device that executes one instruction per instruction cycle (200 ns at 20 MHz), offers 35 single-word instructions, and stores the program code in one-time-programmable EPROM rather than flash. PIC16C parts sit between simple PIC10/12/16 base-line devices and the flash-based PIC18 mid-range family, and were Microchip's mainstream mid-range 8-bit controller from the mid-1990s through the early 2000s before being superseded by flash PIC16F variants.
Key features of the PIC16C74A-20/PT include: 33 digital I/O pins, an 8-channel 8-bit ADC, two CCP modules, a USART, an MSSP (SPI / I2C) port, three timers, a watchdog timer with on-chip RC oscillator, and a brown-out reset. The 20 MHz oscillator speed corresponds to a 200 ns instruction cycle, suitable for real-time control loops up to a few kHz.
The device operates from 4.0 V to 6.0 V across 0 C to +70 C commercial temperature range (this -20/PT suffix indicates 20 MHz, commercial temp, TQFP package). Internal architecture uses a 14-bit instruction word with 8-bit data path, providing predictable interrupt latency of 5 instruction cycles and a single-level hardware stack depth of 8, which limits nested subroutine depth.
Typical applications include industrial control panels, appliance controllers, automotive body electronics, sensor signal conditioning, low-cost motor control and embedded data acquisition. The PIC16C74A is also widely used in legacy designs and educational labs.
A critical design consideration: OTP memory cannot be erased, so firmware must be fully validated before programming - the flash-based PIC16F74 is the recommended modern substitute when in-field firmware updates are needed.
This page consolidates distributor pricing, parametric drop-in alternatives, and design guidance that goes beyond the manufacturer's datasheet to support engineers sourcing legacy PIC16C74A inventory.
Bộ thay thế dễ dàng lắp đặt cho PIC16C74A-20/PT — 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 PIC16C74A-20/PT (cùng hình factor và footprint) — khác nhau ở Package, Program Memory Size, ADC, Core Architecture, Watchdog Timer.
PIC16C74A-20I/PT
✅ Drop-In📋 Tham chiếu thay thế (không có trong danh mục)
PIC16C74B-20I/PT
✅ Drop-InLiên hệ để biết giá
Xem tài liệu →PIC16C74A-20/PQ
✅ Drop-In ⚠️ Thông số chưa được xác minhLiên hệ để biết giá
Xem tài liệu →PIC16F74-I/PT
✅ Drop-InLiên hệ để biết giá
Xem tài liệu →PIC16F747-I/PT
✅ Drop-InLiên hệ để biết giá
Xem tài liệu →PIC16C74A-20/PT Tỷ lệ tối đa & tính chất điện
| Core Architecture | PIC 8-bit Harvard RISC |
| Program Memory Type | OTP EPROM |
| Program Memory Size | 7 KB (4 K x 14) |
| RAM Size | 192 x 8 bytes |
| Maximum CPU Clock | 20 MHz |
| Instruction Cycle Time | 200 ns |
| Number of I/O Pins | 33 |
| ADC | 8 channels, 8-bit |
| Timers | 3 (Timer0, Timer1, Timer2) |
| Capture/Compare/PWM (CCP) | 2 modules |
| Communication | USART, MSSP (SPI / I2C) |
| Operating Voltage | 4.0 V to 6.0 V |
| Nhiệt độ hoạt động | 0 C to +70 C (commercial) |
| Hộp | 44-pin TQFP (10 x 10 mm) |
| Kiểu lắp đặt | Surface Mount |
| Watchdog Timer | Yes, with on-chip RC oscillator |
| Brown-Out Reset (BOR) | Yes |
Cấu hình chân PIC16C74A-20/PT
| Chân 1 | MCLR/VPP — Master clear (reset) input / programming voltage |
| Chân 2 | RA0/AN0 — PORTA bit 0 / analog input 0 |
| Chân 3 | RA1/AN1 — PORTA bit 1 / analog input 1 |
| Chân 4 | RA2/AN2 — PORTA bit 2 / analog input 2 |
| Chân 5 | RA3/AN3/VREF — PORTA bit 3 / analog input 3 / ADC voltage reference |
| Chân 6 | RA4/T0CKI — PORTA bit 4 / Timer0 clock input |
| Chân 7 | RA5/AN4/SS — PORTA bit 5 / analog input 4 / SPI slave select |
| Chân 8 | RE0/RD — PORTE bit 0 / parallel port read control |
| Chân 9 | RE1/WR — PORTE bit 1 / parallel port write control |
| Chân 10 | RE2/CS — PORTE bit 2 / parallel port chip select |
| Chân 11 | VDD — Positive supply voltage |
| Chân 12 | VSS — Ground reference |
| Chân 13 | OSC1/CLKIN — Oscillator input / external clock in |
| Chân 14 | OSC2/CLKOUT — Oscillator output / clock out |
| Chân 15 | RC0/T1OSO/T1CKI — PORTC bit 0 / Timer1 oscillator out / Timer1 clock in |
| Chân 16 | RC1/T1OSI/CCP2 — PORTC bit 1 / Timer1 oscillator in / CCP2 |
| Chân 17 | RC2/CCP1 — PORTC bit 2 / CCP1 PWM output |
| Chân 18 | RC3/SCK/SCL — PORTC bit 3 / SPI clock / I2C clock |
| Chân 19 | RC4/SDI/SDA — PORTC bit 4 / SPI data in / I2C data |
| Chân 20 | RC5/SDO — PORTC bit 5 / SPI data out |
| Chân 21 | RC6/TX/CK — PORTC bit 6 / USART transmit / clock |
| Chân 22 | RC7/RX/DT — PORTC bit 7 / USART receive / data |
| Chân 23 | RD0/PSP0 — PORTD bit 0 / parallel slave port bit 0 |
| Chân 24 | RD1/PSP1 — PORTD bit 1 / parallel slave port bit 1 |
| Chân 25 | RD2/PSP2 — PORTD bit 2 / parallel slave port bit 2 |
| Chân 26 | RD3/PSP3 — PORTD bit 3 / parallel slave port bit 3 |
| Chân 27 | RD4/PSP4 — PORTD bit 4 / parallel slave port bit 4 |
| Chân 28 | RD5/PSP5 — PORTD bit 5 / parallel slave port bit 5 |
| Chân 29 | RD6/PSP6 — PORTD bit 6 / parallel slave port bit 6 |
| Chân 30 | RD7/PSP7 — PORTD bit 7 / parallel slave port bit 7 |
| Chân 31 | VSS — Ground reference |
| Chân 32 | VDD — Positive supply voltage |
| Chân 33 | RB0/INT — PORTB bit 0 / external interrupt |
| Chân 34 | RB1 — PORTB bit 1 |
| Chân 35 | RB2 — PORTB bit 2 |
| Chân 36 | RB3 — PORTB bit 3 |
| Chân 37 | RB4 — PORTB bit 4 |
| Chân 38 | RB5 — PORTB bit 5 |
| Chân 39 | RB6/PGC — PORTB bit 6 / ICSP clock |
| Chân 40 | RB7/PGD — PORTB bit 7 / ICSP data |
| Chân 41 | NC — Not connected (per datasheet) |
| Chân 42 | NC — Not connected (per datasheet) |
| Chân 43 | NC — Not connected (per datasheet) |
| Chân 44 | NC — Not connected (per datasheet) |
Ứng dụng tiêu biểu
PIC16C74A-20/PT phù hợp cho 6 Áp dụngs: Industrial Control Panel, Appliance Controller (Washing Machine / Dishwasher), Automotive Body Electronics (Legacy), Sensor Signal Conditioning & Data Acquisition, Low-Cost Motor Control (Brushed DC / Stepper), Educational & Legacy Embedded Designs.
Industrial Control Panel
The PIC16C74A-20/PT is well suited to industrial front-panel controllers because it integrates 33 I/O lines with 25 mA source/sink per pin (sufficient to drive relays, optocouplers and LED indicators without external buffers), an 8-channel 8-bit ADC for reading panel-mounted sensors, plus a USART for talking to a host PLC. The 200 ns instruction cycle at 20 MHz provides the throughput needed to scan key matrices and refresh 7-segment displays with no perceivable lag. Pair it with the PIC16F74-I/PT as the modern flash equivalent when in-circuit updates are required.
Được đề xuất
Appliance Controller (Washing Machine / Dishwasher)
Major home appliances such as washing machines and dishwashers historically use the PIC16C74A-20/PT as the main controller because of its on-chip ADC for water-level and temperature sensing, two CCP modules for PWM-driven motor and valve control, and a robust instruction set that supports finite-state-machine firmware patterns. The 20 MHz core and 192 bytes of RAM are sufficient for the small scheduler tasks typical of these designs. The commercial 0 C to +70 C operating range covers indoor appliance environments without derating.
Được đề xuất
Automotive Body Electronics (Legacy)
Body-electronics modules such as mirror controllers, seat-position memory and climate-control panels have used the PIC16C74A-20/PT because its 33 I/O lines can drive multiple DC loads directly, the USART connects to a body-controller network, and the MSSP supports SPI/I2C sensor links. However, automotive programs now mandate AEC-Q100 qualified parts; the PIC16C74A is not AEC-Q100 qualified, so new designs should use the PIC16F74-I/PT (extended temp) plus AEC-Q100 graded companion parts. Existing fleets continue to use PIC16C74A-20/PT for repair.
Được đề xuất
Sensor Signal Conditioning & Data Acquisition
The PIC16C74A-20/PT serves as a low-cost sensor front-end with its 8-channel 8-bit ADC for thermocouple, pressure and flow sensors, MSSP for SPI/I2C digital sensors, and USART for forwarding readings to a host. At a 20 MHz clock the ADC achieves the datasheet's ~20 kSPS conversion rate, more than enough for slow process-control loops. With 192 bytes of RAM the part can buffer short acquisition bursts before transmitting.
Được đề xuất
Low-Cost Motor Control (Brushed DC / Stepper)
The PIC16C74A-20/PT provides two CCP modules that can drive brushed DC motors via PWM and stepper motors via software sequencing, while the 20 MHz instruction cycle gives precise PWM resolution at typical 1-20 kHz switching frequencies. Its 25 mA per-pin drive simplifies H-bridge interface designs and reduces the bill of materials. Existing motor-control designs continue to use the PIC16C74A-20/PT as a stable, well-characterized solution.
Được đề xuất
Educational & Legacy Embedded Designs
The PIC16C74A-20/PT is widely used in university courses and hobby projects because its 35-instruction PIC16C RISC architecture is easy to teach, the 44-pin TQFP package breaks out enough peripherals for serious projects, and abundant reference code exists online. New learners should know that the part is OTP (cannot be re-programmed) - the flash-based PIC16F74-I/PT is recommended for class projects where firmware will be iterated multiple times.
Được đề xuất
Tóm tắt các sản phẩm được đề xuất
Dữ liệu tham khảo kỹ thuật cho PIC16C74A-20/PT — 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 | PIC16C74A-20I/PT | PIC16C74B-20I/PT | PIC16C74A-20/PQ | PIC16F74-I/PT | PIC16F747-I/PT |
|---|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 44-pin TQFP (10 x 10 mm) | 44-pin TQFP - same | 44-pin TQFP - same | 44-pin TQFP - same | 44-pin TQFP - same | 44-pin TQFP - same |
| Program Memory Type | OTP (7 KB) | OTP (7 KB) | OTP (7 KB) | OTP (7 KB) | Flash (7 KB) | Flash (7 KB) |
| Maximum Clock | 20 MHz | 20 MHz | 20 MHz | 20 MHz | 20 MHz | 20 MHz |
| RAM Size | 192 bytes | 192 bytes | 192 bytes | 192 bytes | 192 bytes | 256 bytes |
| Number of I/O | 33 | 33 | 33 | 33 | 33 | 36 |
| Operating Temperature | 0 C to +70 C | -40 C to +85 C | -40 C to +85 C | -40 C to +85 C | -40 C to +85 C | -40 C to +85 C |
| In-Circuit Programming | No (OTP) | No (OTP) | No (OTP) | No (OTP) | Yes (ICSP) | Yes (ICSP) |
Bảo phân biệt quan trọng
- Drop-in silicon-replacement available (vsPIC16C74B-20I/PT)
- Flash-based modern equivalent (vsPIC16F74-I/PT)
- Higher peripheral density in same package (vsPIC16F747-I/PT)
Ghi chú thiết kế
PIC16C74A-20/PT is OTP EPROM - firmware cannot be erased and re-written. Always validate code on a flash equivalent (PIC16F74-I/PT) or a windowed PIC16C74A-20/JW sample before committing to OTP production parts. Also confirm the date code supports your lead-free or RoHS requirements, because pre-RoHS TQFP reels may contain Pb-bearing solder finish.
PIC16C74A-20/PT operates from 4.0 V to 6.0 V, not 3.3 V. Designs migrating from 5 V to 3.3 V systems must use the PIC16LF or PIC18F family instead. Place a 100 nF decoupling capacitor as close as possible to each VDD pin (11 and 32) and a bulk 10 uF tantalum or ceramic at the board entry. The brown-out reset should be enabled in configuration fuses to protect against unstable VDD at power-up.
Keep the OSC1/OSC2 traces short and surround them with a ground pour to minimize EMI, especially when using a high-speed 20 MHz crystal. The 44-pin TQFP (10 x 10 mm) is a fine-pitch surface-mount package (0.8 mm pitch) - use a reflow profile that respects the manufacturer's MSL rating and avoid hand-rework where possible. Tie the MCLR pin through a 10 kohm pull-up to VDD and place the reset capacitor close to the pin to ensure clean power-on-reset behavior.
When using the ADC, add a small RC filter (typically 100 ohm + 100 nF) on each analog input to suppress noise from digital switching. Avoid routing ADC traces parallel to high-frequency digital lines such as the oscillator or PWM outputs. Configure the ADC acquisition time and conversion clock according to the datasheet's electrical characteristics to maintain rated 8-bit accuracy across temperature.
Thông tin tuân thủ
PIC16C74A-20/PT was originally released before RoHS became mandatory; lead-free status depends on date code. Not AEC-Q100 qualified - use PIC16F74-I/PT or higher-grade parts for automotive programs. Conflict-minerals compliance per Microchip's standard CMRT filings.