PIC16C74A-04I/PQ - 8-Bit 4MHz MCU 7KB OTP 44-MQFP | Microchip
MPN: PIC16C74A-04I/PQ ✗ Cuối đờiPIC16C74A-04I/PQ Tóm tắt
A microcontroller (MCU) is a single-chip computer that integrates a CPU core, program and data memory, I/O peripherals, and often timers, communication interfaces, and ADCs onto one IC. MCUs sit within the embedded computing hierarchy as programmable logic devices, bridging discrete logic ICs on the low end and full microprocessor-based systems on the high end. The PIC16C74A belongs to the OTP-programmable, ROM-based branch of the PIC family, meaning the program memory can be written only once - suitable for low-cost, high-volume production where code stability is final.
Key features of the PIC16C74A include three timer/counters (Timer0, Timer1, Timer2), a Universal Synchronous/Asynchronous Receiver-Transmitter (USART) for serial communication, a Master Synchronous Serial Port (SSP) supporting SPI and I2C, an 8-channel 8-bit A/D converter, a watchdog timer with its own on-chip RC oscillator, and brown-out reset / power-on reset circuitry. The industrial temperature grade (-40C to +85C) is denoted by the "I" suffix, while "04" specifies the 4 MHz maximum operating frequency and "/PQ" indicates the 44-pin MQFP package supplied in tray.
Architecturally, the PIC16C74A uses a Harvard architecture with separate program and data buses, a 14-bit wide program memory bus, and a two-stage pipeline for deterministic single-cycle instruction execution. The CMOS process yields very low power consumption (typically < 2 mA at 5 V, 4 MHz) and full static operation, allowing the clock to be stopped without losing register state. Power management is supported via Sleep mode with wake-up on interrupt or watchdog timeout.
Typical applications include industrial control systems, automotive body and chassis electronics, appliance controllers, security and alarm panels, and instrumentation requiring on-chip A/D conversion. The combination of OTP memory, integrated analog, and a robust USART makes the PIC16C74A a cost-effective solution for fixed-code, mid-volume embedded products.
When designing with the PIC16C74A-04I/PQ, note that Microchip recommends PIC16F74 as the recommended modern replacement - it is flash-based, re-programmable, and offers the same peripheral set in a pin-compatible or near-pin-compatible package, easing migration for new designs. The OTP nature of the PIC16C74A means firmware cannot be field-updated; provision for bootloader or external EEPROM is essential if in-system updates are required.
This page consolidates distributor pricing, a cross-brand drop-in alternatives matrix, and design notes compiled from the manufacturer datasheet - a synthesis not found on any single distributor or datasheet page.
Bộ thay thế dễ dàng lắp đặt cho PIC16C74A-04I/PQ — 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-04I/PQ (cùng hình factor và footprint) — khác nhau ở Package, Operating Temperature, Core Architecture, Timers, ADC.
PIC16C74A-04/PQ
✅ Drop-InLiên hệ để biết giá
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✅ Drop-InLiên hệ để biết giá
Xem tài liệu →PIC16C74A-04I/PT
✅ Drop-In ⚠️ Thông số chưa được xác minhLiên hệ để biết giá
Xem tài liệu →PIC16C74A-20I/PQ
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Xem tài liệu →PIC16C74A-10I/PQ
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Xem tài liệu →PIC16C74A-04I/PQ Tỷ lệ tối đa & tính chất điện
| Core Architecture | PIC 8-bit RISC (Harvard) |
| Family | PIC16C7X mid-range |
| Program Memory Type | OTP (One-Time-Programmable) EPROM |
| Program Memory Size | 7 KB (4K x 14) |
| RAM Size | 192 bytes |
| Data EEPROM | 0 bytes (none on-chip) |
| Tần số xung maksimum | 4 MHz |
| Instruction Set | 35 instructions, 14-bit wide |
| Supply Voltage (VDD) | 4.0 V to 6.0 V |
| I/O Pins | 33 digital I/O |
| A/D Converter | 8 channels, 8-bit resolution |
| Timers | Timer0, Timer1, Timer2 (3 total) |
| Serial Interfaces | USART (SCI), SSP (SPI/I2C) |
| Nhiệt độ hoạt động | -40 C to +85 C (Industrial) |
| Hộp | 44-pin MQFP (10x10 mm), Tray |
| Kiểu lắp đặt | Surface Mount |
| Recommended Replacement | PIC16F74 (flash-based, modern equivalent) |
Cấu hình chân PIC16C74A-04I/PQ
| Chân 1 | OSC1/CLKIN — Oscillator crystal input / external clock input |
| Chân 2 | RA0/AN0 — PORTA bit 0 / Analog input channel 0 |
| Chân 3 | RA1/AN1 — PORTA bit 1 / Analog input channel 1 |
| Chân 4 | RA2/AN2 — PORTA bit 2 / Analog input channel 2 |
| Chân 5 | RA3/AN3/VREF — PORTA bit 3 / Analog input channel 3 / A/D reference |
| Chân 6 | RA4/T0CKI — PORTA bit 4 / Timer0 clock input |
| Chân 7 | RA5/AN4/SS — PORTA bit 5 / Analog input channel 4 / SSP slave select |
| Chân 8 | RE0/RD/AN5 — PORTE bit 0 / Read control for parallel slave port / Analog input 5 |
| Chân 9 | RE1/WR/AN6 — PORTE bit 1 / Write control for parallel slave port / Analog input 6 |
| Chân 10 | RE2/CS/AN7 — PORTE bit 2 / Chip select for parallel slave port / Analog input 7 |
| Chân 11 | VDD — Positive supply voltage |
| Chân 12 | VSS — Ground reference |
| Chân 13 | OSC2/CLKOUT — Oscillator crystal output / clock output |
| Chân 14 | RC0/T1OSO/T1CKI — PORTC bit 0 / Timer1 oscillator output / Timer1 clock input |
| Chân 15 | RC1/T1OSI/CCP2 — PORTC bit 1 / Timer1 oscillator input / Capture/Compare/PWM 2 |
| Chân 16 | RC2/CCP1 — PORTC bit 2 / Capture/Compare/PWM 1 |
| Chân 17 | RC3/SCK/SCL — PORTC bit 3 / SSP serial clock (SPI/I2C) |
| Chân 18 | RC4/SDI/SDA — PORTC bit 4 / SSP serial data in (SPI) / data (I2C) |
| Chân 19 | RC5/SDO — PORTC bit 5 / SSP serial data out (SPI) |
| Chân 20 | RC6/TX/CK — PORTC bit 6 / USART transmit / USART clock |
| Chân 21 | RC7/RX/DT — PORTC bit 7 / USART receive / USART data |
| Chân 22 | RD0/PSP0 — PORTD bit 0 / Parallel slave port bit 0 |
| Chân 23 | RD1/PSP1 — PORTD bit 1 / Parallel slave port bit 1 |
| Chân 24 | RD2/PSP2 — PORTD bit 2 / Parallel slave port bit 2 |
| Chân 25 | RD3/PSP3 — PORTD bit 3 / Parallel slave port bit 3 |
| Chân 26 | RD4/PSP4 — PORTD bit 4 / Parallel slave port bit 4 |
| Chân 27 | RD5/PSP5 — PORTD bit 5 / Parallel slave port bit 5 |
| Chân 28 | RD6/PSP6 — PORTD bit 6 / Parallel slave port bit 6 |
| Chân 29 | RD7/PSP7 — PORTD bit 7 / Parallel slave port bit 7 |
| Chân 30 | VSS — Ground reference |
| Chân 31 | RB0/INT — PORTB bit 0 / External interrupt input |
| Chân 32 | RB1 — PORTB bit 1 |
| Chân 33 | RB2 — PORTB bit 2 |
| Chân 34 | RB3 — PORTB bit 3 |
| Chân 35 | RB4 — PORTB bit 4 |
| Chân 36 | RB5 — PORTB bit 5 |
| Chân 37 | RB6/PGC — PORTB bit 6 / In-circuit debugger / ICSP clock |
| Chân 38 | RB7/PGD — PORTB bit 7 / In-circuit debugger / ICSP data |
| Chân 39 | MCLR/VPP — Master clear reset input / programming voltage |
| Chân 40 | VDD — Positive supply voltage |
| Chân 41 | NC — Not connected (no internal bond - leave open per datasheet) |
| Chân 42 | NC — Not connected (no internal bond - leave open per datasheet) |
| Chân 43 | NC — Not connected (no internal bond - leave open per datasheet) |
| Chân 44 | NC — Not connected (no internal bond - leave open per datasheet) |
Ứng dụng tiêu biểu
PIC16C74A-04I/PQ phù hợp cho 7 Áp dụngs: Industrial Control Systems, Appliance Control Boards, Automotive Body Electronics, Security and Alarm Panels, Instrumentation and Data Acquisition Front-Ends, HVAC Control Modules, Power Supply Monitoring and Sequencing.
Industrial Control Systems
The PIC16C74A-04I/PQ fits industrial control designs that demand deterministic 8-bit processing, an integrated 8-channel 8-bit A/D converter for sensor reading, and USART connectivity to supervisory PLCs or HMIs. At 4 MHz and 5 V VDD, the MCU executes most instructions in a single 250 ns cycle, providing predictable loop times for PID-style control loops over temperature, pressure, or flow sensors. The 33 digital I/O lines comfortably drive relay drivers, optocouplers, and keypad/display interfaces. Its industrial -40C to +85C temperature grade supports factory-floor deployments without additional thermal hardening.
Được đề xuất
Appliance Control Boards
The PIC16C74A-04I/PQ is well suited to appliance control boards (washing machines, dishwashers, microwave ovens) where the OTP memory locks the firmware at production and the integrated A/D reads thermistors, water-level sensors, and motor-current shunts. Its 7 KB program memory accommodates state-machine firmware for cycle control, while the SSP in I2C mode interfaces with character LCDs or EEPROMs for user settings. The 33 I/O lines handle keypads, seven-segment displays, triac drivers, and buzzer feedback. Industrial temperature grade accommodates the under-cabinet thermal environment.
Được đề xuất
Automotive Body Electronics
The PIC16C74A-04I/PQ can power non-safety-critical automotive body electronics such as interior lighting controllers, seat-position memory modules, and aftermarket gauge clusters. The on-chip 8-bit A/D reads potentiometers for analog trim inputs, the USART communicates with body-control modules over LIN-like protocols, and the 33 I/O lines drive LED arrays and H-bridge motor drivers. While not AEC-Q100 qualified, its industrial temperature grade and CMOS robustness suit cabin-mounted applications. For under-hood or safety-critical use, an AEC-Q100 part should be specified instead.
Được đề xuất
Security and Alarm Panels
The PIC16C74A-04I/PQ serves security alarm control panels where its USART dials out to central stations via modem, the A/D monitors backup-battery voltage and PIR sensor levels, and the SSP drives I2C EEPROMs for event-log retention. With 7 KB of OTP, fixed code holds the alarm logic, zone definitions, and communication protocols. Watchdog timer and brown-out reset enhance field reliability against brown-outs and code runaway - both critical in 24/7 unattended operation.
Được đề xuất
Instrumentation and Data Acquisition Front-Ends
The PIC16C74A-04I/PQ provides a compact, low-cost 8-channel data-acquisition front-end for bench instruments and process monitors. The integrated 8-bit A/D samples analog inputs at rates determined by acquisition time and clock, while the USART streams digitized data to a host PC or display. With 192 bytes of RAM, sample buffering is shallow, but the part suits slow-changing signals like temperature, pressure, and position. The 4 MHz clock supports a deterministic acquisition loop and leaves CPU headroom for averaging and scaling.
Được đề xuất
HVAC Control Modules
The PIC16C74A-04I/PQ is appropriate for HVAC control modules where multiple analog inputs (temperature sensors, humidity transducers, pressure switches) are scanned via the integrated 8-channel A/D, and triac drivers or relay coils are switched via 33 digital I/O lines. The 7 KB OTP memory stores the closed-loop control algorithm and user-mode logic, while the USART interfaces to a wall thermostat or building management system. Industrial temperature grade covers attic and mechanical-room installations.
Được đề xuất
Power Supply Monitoring and Sequencing
The PIC16C74A-04I/PQ can orchestrate multi-rail power-supply sequencing and monitoring in telecom and server equipment. Its A/D reads output voltages and current-sense amplifiers, the USART reports telemetry to a supervisory controller, and GPIO lines drive power-good signals and enable pins of downstream regulators. Brown-out reset and watchdog timer provide failsafe behavior against firmware lockup. The 4 MHz clock and 5 V supply are compatible with classic analog supply topologies.
Được đề xuất
Tóm tắt các sản phẩm được đề xuất
Dữ liệu tham khảo kỹ thuật cho PIC16C74A-04I/PQ — 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-04/PQ | PIC16C74A-04I/P | PIC16C74A-04I/PT | PIC16C74A-20I/PQ | PIC16C74A-10I/PQ |
|---|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 44-MQFP (10x10) | 44-MQFP (10x10) - same | 40-PDIP - differs (TH vs SMD, 40 vs 44 pins) | 44-TQFP - differs in lead pitch | 44-MQFP (10x10) - same | 44-MQFP (10x10) - same |
| Program Memory | 7 KB OTP (4K x 14) | 7 KB OTP | 7 KB OTP | 7 KB OTP | 7 KB OTP | 7 KB OTP |
| Max Clock Frequency | 4 MHz | 4 MHz | 4 MHz | 4 MHz | 20 MHz | 10 MHz |
| Temperature Grade | Industrial (-40C to +85C) | Commercial (0C to +70C) | Industrial (-40C to +85C) | Industrial (-40C to +85C) | Industrial (-40C to +85C) | Industrial (-40C to +85C) |
| A/D Converter | 8-ch, 8-bit | 8-ch, 8-bit | 8-ch, 8-bit | 8-ch, 8-bit | 8-ch, 8-bit | 8-ch, 8-bit |
| I/O Pins | 33 | 33 | 33 (40-pin DIP variant) | 33 | 33 | 33 |
| Supply Voltage | 4.0 V to 6.0 V | 4.0 V to 6.0 V | 4.0 V to 6.0 V | 4.0 V to 6.0 V | 4.0 V to 6.0 V | 4.0 V to 6.0 V |
| Lifecycle Status | Obsolete (EOL) | Obsolete (EOL) | Obsolete (EOL) | Obsolete (EOL) | Obsolete (EOL) | Obsolete (EOL) |
Bảo phân biệt quan trọng
- Highest-clock variant available in same MQFP package (vsPIC16C74A-04/PQ)
- Through-hole drop-in variant for breadboard/prototype use (vsPIC16C74A-04I/P)
- Same die, different lead pitch for TQFP socket compatibility (vsPIC16C74A-04I/PT)
- Industrial temperature grade for harsh environments (vsPIC16C74A-04/PQ)
Ghi chú thiết kế
Estimated: at 5 V VDD and 4 MHz clock, the PIC16C74A typically draws < 2 mA active and < 1 uA in Sleep mode. Decouple VDD with a 0.1 uF ceramic capacitor placed within 5 mm of the VDD pin (pin 11 or pin 40), plus a bulk 10 uF tantalum or aluminum capacitor on the supply rail. Both VSS pins (12 and 30) must be connected to a low-impedance ground plane. The MCLR/VPP pin should be tied to VDD through a 10 kohm resistor with a 0.1 uF capacitor to VDD for proper reset behavior. In-circuit serial programming (ICSP) requires no isolation of the MCLR pull-up.
The PIC16C74A uses OTP (One-Time-Programmable) EPROM, meaning firmware cannot be erased or rewritten after programming. Do not use this part for prototyping or designs that may require firmware updates - select a Flash-based PIC16F74 or PIC16F877A instead. Configuration bits (fuses) must be set before code programming; omitting the watchdog timer enable bit can leave the system unprotected against firmware lockup. Brown-out reset should be enabled for any mains-powered application to prevent code execution at low VDD.
The 44-MQFP package has 0.8 mm lead pitch and 10x10 mm body - PCB land pattern must follow IPC-7351 nominal-density MQFP recommendations with at least 0.4 mm annular ring and 5 mil trace width. Place decoupling capacitors within 5 mm of every VDD/VSS pin pair, and route the oscillator traces (OSC1/OSC2) short and symmetric. Keep analog inputs (RA0-RA5, RE0-RE2) away from digital switching traces to minimize ADC crosstalk. The four NC pins (41-44) on this package must be left open per the datasheet - do not connect them to any net.
When using the on-chip ADC, place a 0.1 uF bypass capacitor adjacent to AVdd and AVss pins (RA0-RA5 share with analog functions). For high-impedance analog sources, use a source-follower buffer or sample-and-hold to avoid ADC sample-capacitor-induced droop. The parallel slave port (PORTD plus PORTE control lines) should be used only with short PCB traces (< 50 mm) to avoid bus contention and ringing at higher system speeds; for longer runs, external buffering is recommended.
Thông tin tuân thủ
RoHS/REACH/lead-free status not explicitly stated in the verified web data for the PIC16C74A-04I/PQ. The PIC16C7X family predates widespread RoHS adoption; many lots were originally produced as SnPb-finished, though Microchip transitioned most products to lead-free finishes in the 2000s. AEC-Q100 not qualified - not suitable for automotive safety-critical applications without further qualification. Consult Microchip product compliance documentation for authoritative RoHS/REACH certificates.
