PIC16C74B-20/L - 8-Bit OTP MCU 7KB 20MHz 44-PLCC | Microchip
MPN： PIC16C74B-20/L ✓ 啟用中PIC16C74B-20/L 概覽
What is a PIC mid-range 8-bit MCU? A PIC (Peripheral Interface Controller) microcontroller is a compact integrated circuit that combines a CPU, memory, and programmable peripherals on a single die. The mid-range family (PIC16C) sits between baseline (PIC10/12/16F general-purpose) and enhanced mid-range (PIC18) families, offering 35 single-word instructions, 14-bit instruction width, and a balance of peripherals for embedded control. PIC16C parts use OTP (one-time programmable) EPROM program memory, which is differentiated from flash-based PIC16F variants.
Key features include 8 channels of 8-bit Analog-to-Digital conversion, two 8-bit and one 16-bit timer/counter modules, two Capture/Compare/PWM (CCP) peripherals, a synchronous serial port configurable as SPI or I2C, and a USART for asynchronous serial communication. Operating voltage spans 4.0V to 5.5V, suiting legacy 5V industrial and embedded designs.
The architecture employs a Harvard design with separate program and data buses, allowing 14-bit instruction fetch and 8-bit data access in a single cycle. Brown-out Reset (BOR), Watchdog Timer (WDT), and Power-on Reset (POR) provide robust operation in noisy environments. The 44-PLCC package gives 33 I/O - more than 28-pin PIC16C73 family members.
Typical applications include industrial process controllers, motor control subsystems, instrumentation front-ends, and automotive body electronics where code stability and 5V tolerance outweigh the need for in-system reprogrammability.
When migrating designs, consider PIC16F74 flash variants for in-circuit reprogrammability - the pinout is compatible with PLCC-44 footprints.
This page synthesizes current distributor pricing, drop-in PIC16C74B alternatives, and PLCC-44 design notes not consolidated on the Microchip product page.
直接替換替代品，適用於 PIC16C74B-20/L — 相同封裝，腳位對腳位相容。需重新設計 PCB 的不同封裝零件不列入。
此系列的變體
與下列產品可直接替換的同系列型號： PIC16C74B-20/L （相同外形與佔位） — 差異在於 Package, Core Architecture, Serial Interfaces, Timers, ADC.
PIC16C74B-04I/L
✅ 直接替換聯絡詢價
查看資料表 →PIC16C74BT-20/L
✅ 直接替換📋 參考替代品（不在目錄中）
PIC16C74B-20E/L
✅ 直接替換📋 參考替代品（不在目錄中）
PIC16F74-I/L
✅ 直接替換聯絡詢價
查看資料表 →PIC16C74A-20/L
✅ 直接替換聯絡詢價
查看資料表 →PIC16C74B-20/L 最大額定值與電氣特性
| Core Architecture | 8-bit PIC mid-range (14-bit instruction) |
| Program Memory Size | 7 KB (4K x 14) OTP EPROM |
| RAM Size | 192 bytes |
| Data EEPROM | Not present (OTP device) |
| Maximum CPU Frequency | 20 MHz |
| Instruction Cycle Time | 200 ns |
| Supply Voltage (Vdd) | 4.0 V to 5.5 V |
| I/O Pins | 33 |
| Analog-to-Digital Converter | 8 channels x 8-bit |
| Timers | 2 x 8-bit + 1 x 16-bit |
| Capture/Compare/PWM | 2 CCP modules |
| Serial Interfaces | SPI, I2C (MSSP), USART |
| 封裝 / 外殼 | 44-PLCC (16.59 x 16.59 mm), J-Lead |
| 工作溫度 | 0 C to +70 C (commercial) |
| 安裝類型 | Surface Mount |
| ROM Type | One-Time Programmable (OTP) |
| RoHS 狀態 | Compliant |
PIC16C74B-20/L 腳位配置
| 腳位 1 | MCLR/VPP — Master Clear (Reset) input / Programming voltage |
| 腳位 2 | RA0/AN0 — PORTA bit 0 / Analog input channel 0 |
| 腳位 3 | RA1/AN1 — PORTA bit 1 / Analog input channel 1 |
| 腳位 4 | RA2/AN2 — PORTA bit 2 / Analog input channel 2 |
| 腳位 5 | RA3/AN3/VREF — PORTA bit 3 / Analog input 3 / ADC reference |
| 腳位 6 | RA4/T0CKI — PORTA bit 4 / Timer 0 clock input |
| 腳位 7 | RA5/AN4/SS — PORTA bit 5 / Analog 4 / SPI slave select |
| 腳位 8 | RE0/RD/AN5 — PORTE bit 0 / Read control / Analog 5 |
| 腳位 9 | RE1/WR/AN6 — PORTE bit 1 / Write control / Analog 6 |
| 腳位 10 | RE2/CS/AN7 — PORTE bit 2 / Chip select / Analog 7 |
| 腳位 11 | VSS — Ground |
| 腳位 12 | OSC1/CLKIN — Oscillator input / external clock |
| 腳位 13 | OSC2/CLKOUT — Oscillator output / clock out |
| 腳位 14 | RC0/T1OSO/T1CKI — PORTC bit 0 / Timer1 oscillator out / clock in |
| 腳位 15 | RC1/T1OSI/CCP2 — PORTC bit 1 / Timer1 oscillator in / CCP2 |
| 腳位 16 | RC2/CCP1 — PORTC bit 2 / Capture Compare PWM 1 |
| 腳位 17 | RC3/SCK/SCL — PORTC bit 3 / SPI clock / I2C clock |
| 腳位 18 | RC4/SDI/SDA — PORTC bit 4 / SPI data in / I2C data |
| 腳位 19 | RC5/SDO — PORTC bit 5 / SPI data out |
| 腳位 20 | RC6/TX/CK — PORTC bit 6 / USART TX / clock |
| 腳位 21 | RC7/RX/DT — PORTC bit 7 / USART RX / data |
| 腳位 22 | RD0/PSP0 — PORTD bit 0 / Parallel Slave Port bit 0 |
| 腳位 23 | RD1/PSP1 — PORTD bit 1 / Parallel Slave Port bit 1 |
| 腳位 24 | RD2/PSP2 — PORTD bit 2 / Parallel Slave Port bit 2 |
| 腳位 25 | RD3/PSP3 — PORTD bit 3 / Parallel Slave Port bit 3 |
| 腳位 26 | RD4/PSP4 — PORTD bit 4 / Parallel Slave Port bit 4 |
| 腳位 27 | RD5/PSP5 — PORTD bit 5 / Parallel Slave Port bit 5 |
| 腳位 28 | RD6/PSP6 — PORTD bit 6 / Parallel Slave Port bit 6 |
| 腳位 29 | RD7/PSP7 — PORTD bit 7 / Parallel Slave Port bit 7 |
| 腳位 30 | VSS — Ground |
| 腳位 31 | VDD — Positive supply voltage |
| 腳位 32 | RB0/INT — PORTB bit 0 / External interrupt |
| 腳位 33 | RB1 — PORTB bit 1 |
| 腳位 34 | RB2 — PORTB bit 2 |
| 腳位 35 | RB3 — PORTB bit 3 |
| 腳位 36 | RB4 — PORTB bit 4 |
| 腳位 37 | RB5 — PORTB bit 5 |
| 腳位 38 | RB6/PGC — PORTB bit 6 / ICSP clock |
| 腳位 39 | RB7/PGD — PORTB bit 7 / ICSP data |
| 腳位 40 | VSS — Ground (additional) |
| 腳位 41 | VDD — Positive supply voltage (additional) |
| 腳位 42 | NC — Not connected (per datasheet) |
| 腳位 43 | NC — Not connected (per datasheet) |
| 腳位 44 | NC — Not connected (per datasheet) |
典型應用
PIC16C74B-20/L 適用於 6 應用s: Industrial Process Controller, Motor Control Subsystem, Instrumentation Front-End, Automotive Body Electronics, Embedded Sensor Hub, Legacy 5V Embedded Replacement.
Industrial Process Controller
The PIC16C74B-20/L fits industrial process controllers with its 33 I/O pins, 8-channel 8-bit ADC, and 20 MHz execution. Its 4.0-5.5V operation aligns with legacy 24V/5V industrial bus systems, and the 44-PLCC footprint accommodates through-hole or socketed installation common in factory-floor equipment. The 7KB OTP memory stores fixed control algorithms (PID loops, valve sequencing) where code stability outweighs field reprogrammability needs.
推薦
Motor Control Subsystem
The PIC16C74B-20/L serves motor control subsystems via its two Capture/Compare/PWM (CCP) modules that generate precise PWM signals for DC motor speed control. With 200 ns instruction cycle at 20 MHz, the controller can update PID parameters fast enough for closed-loop motor regulation at industrial PWM frequencies. The 8-channel ADC samples current and position feedback, while the USART interfaces to encoder inputs. OTP memory secures the control algorithm from field tampering.
推薦
Instrumentation Front-End
The PIC16C74B-20/L excels in instrumentation front-ends requiring 8 channels of analog input for sensor multiplexing. Its 8-bit ADC delivers 19.5 us conversion at 20 MHz, sufficient for temperature, pressure, and flow sensing at typical industrial sampling rates. The synchronous serial port (SPI/I2C) interfaces with external 12-bit or 16-bit ADCs for higher-resolution measurements, while the USART outputs data to a host controller or display.
推薦
Automotive Body Electronics
The PIC16C74B-20/L is suitable for non-safety automotive body electronics such as climate control panels, lighting controllers, and HVAC actuators. Its extended-temperature sibling PIC16C74B-20E/L (same 44-PLCC) operates from -40 C to +125 C, meeting under-hood thermal demands. The 33 I/O pins handle multiple switch inputs and relay outputs, while the 8-channel ADC reads thermistors and position sensors. OTP memory prevents unauthorized firmware modification in deployed vehicles.
推薦
Embedded Sensor Hub
The PIC16C74B-20/L acts as a sensor hub aggregating data from multiple SPI/I2C sensors and forwarding through USART. Its 192-byte RAM and 7KB program memory handle multi-sensor polling loops and basic digital filtering. The PIC16C74B-20/L's MSSP module addresses multiple I2C slaves, while dedicated timers generate sample-timing interrupts. This makes it ideal for environmental monitoring stations and agricultural sensor networks.
推薦
Legacy 5V Embedded Replacement
The PIC16C74B-20/L serves as a pin-compatible replacement in legacy 5V embedded designs originally built around older PIC16C7x controllers. According to Microchip pin compatibility charts, the 44-PLCC footprint matches PIC16C63A, PIC16C65B, PIC16C73B, and PIC16C74A, enabling direct socket-level substitution. Designers upgrading from older parts benefit from the PIC16C74B's enhanced peripherals (extra ADC channels, second CCP) without PCB rework.
推薦
推薦產品摘要
工程參考資料，適用於 PIC16C74B-20/L — 比較、設計指引及合規資訊。
選型指南
與替代品比較
| 參數 | 本產品 | PIC16C74B-04I/L | PIC16F74-I/L | PIC16C74A-20/L |
|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 44-PLCC | 44-PLCC - same | 44-PLCC - same | 44-PLCC - same |
| CPU Frequency | 20 MHz | 4 MHz | 20 MHz | 20 MHz |
| Program Memory | 7 KB OTP | 7 KB OTP | 7 KB Flash | 4 KB OTP |
| I/O Pins | 33 | 33 | 33 | 33 |
| ADC | 8 ch x 8-bit | 8 ch x 8-bit | 8 ch x 8-bit | 8 ch x 8-bit |
| Operating Voltage | 4.0-5.5 V | 4.0-5.5 V | 2.0-5.5 V (wider range) | 4.0-5.5 V |
| Operating Temperature | 0 C to +70 C | -40 C to +85 C (industrial) | -40 C to +85 C (industrial) | 0 C to +70 C |
主要差異化特點
- Highest program memory in 44-PLCC PIC16C7x family (對比PIC16C74A-20/L)
- Flash-based reprogrammability (對比PIC16C74B-20/L vs PIC16F74-I/L)
- Industrial temperature grade option available (對比PIC16C74B-20E/L)
設計說明
Place a 100 nF decoupling capacitor as close as possible to each Vdd pin (pins 31 and 41 on the 44-PLCC) with the ground return connected to the nearest Vss pin. For 20 MHz operation at full I/O switching load, add a 10 uF bulk tantalum or aluminum polymer capacitor near the MCU. PLCC-44 sockets should use machined-pin sockets (e.g., Aries 44-650000-11) for reliable field replacement in industrial installations.
Brown-out Reset (BOR) must be configured in the configuration word for reliable operation. With Vdd supply transitions below 4.0 V, BOR holds the MCU in reset until stable voltage returns. If 3.3 V operation is required, the PIC16F74-I/L flash variant is recommended since PIC16C74B-20/L is rated only for 4.0-5.5 V operation. Add a 1N4148 diode from MCLR to Vdd for additional ESD protection on the reset line.
OTP (One-Time Programmable) memory cannot be erased - once programmed, the PIC16C74B-20/L cannot be reprogrammed. Always validate code on a flash-based PIC16F74-I/L prototype before committing to OTP production programming. Also note: ICSP (In-Circuit Serial Programming) uses pins RB6/PGC and RB7/PGD, which conflicts with PORTB bit 6/7 use during debug - design the PCB to expose these pins to a programming header without interfering with application circuitry.
合規資訊
RoHS compliant per Microchip product page. PIC16C74B-20/L is not AEC-Q100 qualified; for AEC-Q100 automotive applications use PIC16C74B-20E/L (extended temp grade) or migrate to PIC16F874A automotive-grade variant.
