PIC16C74B-20/PT - 8-Bit 20MHz OTP MCU 7KB | 44-TQFP | Microchip
料号： PIC16C74B-20/PT ✓ 量产中| 数量 | 单价 | 小计 |
|---|---|---|
| 1 | $3.13 | $3.13 |
| 10 | $2.95 | $29.50 |
| 100 | $2.62 | $262.00 |
| 500 | $2.31 | $1,155.00 |
| 1,000 | $2.05 | $2,050.00 |
PIC16C74B-20/PT 概述
What is an 8-bit OTP microcontroller? An OTP (One-Time-Programmable) microcontroller is a class of embedded controller that uses non-erasable PROM (programmable read-only memory) for code storage, sitting within the broader hierarchy of microcontroller -> embedded controller -> semiconductor. OTP parts offer a lower-cost alternative to windowed UV-erasable parts in volume production, since the program is written once during manufacturing test and the die lacks the expensive quartz erasure window. PIC mid-range devices use a RISC instruction set (35 single-word instructions) so every instruction executes in one cycle (200 ns at 20 MHz), with program branches taking two cycles.
Key features include 33 I/O pins, hardware USART for serial communication, dual-mode master/slave SSP for SPI or I2C peripherals, and an integrated 8-channel 8-bit ADC that simplifies sensor-interface designs. The PIC16C7X family is code- and pin-compatible with the earlier PIC16C6X family, easing migration. The Watchdog Timer, power-on reset, brown-out reset, and code protection provide robust embedded reliability for industrial control, instrumentation, and consumer appliances.
Architecturally, the PIC16C74B uses a 14-bit instruction word and a Harvard bus architecture that separates program and data memory, allowing instruction fetch and operand read in the same cycle. The mid-range core implements a hardware multiplier-free ALU that performs arithmetic, logical, and bit-manipulation operations on the working register W, with file registers mapped into banked SRAM. The 8-bit ADC uses successive approximation with a sample-and-hold, capable of 20 µs conversion time.
Typical applications include industrial process control, motor drive front-ends (via CCP/PWM), HVAC control boards, instrumentation front-panels, sensor conditioning, security-system panels, and white-goods controllers. Designers select the PIC16C74B-20/PT when they need more I/O and ADC channels than the smaller 28-pin PIC16C73B.
When designing with this part, confirm the production-fit OTP variant is acceptable for your volume (OTP cannot be reprogrammed). For field-updatable firmware, migrate to the flash-based PIC16F74 or PIC18F equivalents, which are drop-in compatible at the pin level. Use MPLAB X IDE with MPASM or XC8 for code development, and the ICD-series in-circuit debuggers for early prototypes.
This page synthesizes verified distributor pricing, pin-compatible same-family alternatives, and practical design guidance specific to the 44-TQFP variant of the PIC16C74B-20/PT - information not found in a single manufacturer datasheet.
直接替换替代料： PIC16C74B-20/PT ——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： PIC16C74B-20/PT （相同外形与封装尺寸） ——差异在于 Package, Program Memory Size, Serial Interfaces, Program Memory Type, Core Architecture.
快速对比工具——选择替代料号进行并排对比：
PIC16C74AT-20/PT
✅ 直接替换✓ 有现货
$5.55 / 个
查看数据手册 →PIC16C67-20/PT
✅ 直接替换 ⚠️ 规格未核验✓ 有现货
$5.95 / 个
查看数据手册 →PIC16F74-I/PT
✅ 直接替换✓ 有现货
$5.55 / 个
查看数据手册 →PIC16C77-20/PT
✅ 直接替换 ⚠️ 规格未核验✓ 有现货
$7.5 / 个
查看数据手册 →PIC16C74B-20/PT 最大额定值与电气特性
| Family | PIC16C7X (PIC® 16C, mid-range) |
| Core | 8-bit RISC, 35 single-word instructions |
| Clock Speed | 20 MHz maximum |
| Instruction Cycle | 200 ns (4 clock periods) |
| Program Memory Type | OTP (One-Time-Programmable) |
| Program Memory Size | 7 KB (4K x 14 bits) |
| Data RAM | 192 bytes |
| I/O Pins | 33 |
| ADC | 8 channels x 8-bit |
| Timers | Timer0 (8-bit), Timer1 (16-bit), Timer2 (8-bit) |
| CCP/PWM Modules | 2 (Capture/Compare/PWM) |
| Serial Interfaces | SSP (SPI master/slave or I2C) + USART/SCI |
| 电源电压 | 4.0 V to 5.5 V |
| 封装 | 44-pin TQFP (10x10 mm), PT |
| 安装类型 | Surface Mount |
| 工作温度 | 0C to +70C (commercial) |
PIC16C74B-20/PT 引脚配置
| 引脚 1 | RA0/AN0 — PORTA bit 0 / Analog input 0 |
| 引脚 2 | RA1/AN1 — PORTA bit 1 / Analog input 1 |
| 引脚 3 | RA2/AN2 — PORTA bit 2 / Analog input 2 |
| 引脚 4 | RA3/AN3/VREF+ — PORTA bit 3 / Analog input 3 / VREF+ |
| 引脚 5 | RA4/T0CKI — PORTA bit 4 / Timer0 clock input |
| 引脚 6 | RA5/AN4/SS — PORTA bit 5 / Analog input 4 / SPI Slave Select |
| 引脚 7 | AVDD — Analog supply voltage |
| 引脚 8 | AVSS — Analog ground |
| 引脚 9 | OSC1/CLKIN — Oscillator input / external clock |
| 引脚 10 | OSC2/CLKOUT — Oscillator output / clock out |
| 引脚 11 | RC0/T1OSO/T1CKI — PORTC bit 0 / Timer1 oscillator out / Timer1 clock |
| 引脚 12 | RC1/T1OSI/CCP1 — PORTC bit 1 / Timer1 oscillator in / CCP1 |
| 引脚 13 | RC2/CCP1 — PORTC bit 2 / CCP1 |
| 引脚 14 | RC3/SCK/SCL — PORTC bit 3 / SPI clock / I2C clock |
| 引脚 15 | RC4/SDI/SDA — PORTC bit 4 / SPI data in / I2C data |
| 引脚 16 | RC5/SDO — PORTC bit 5 / SPI data out |
| 引脚 17 | RC6/TX/CK — PORTC bit 6 / USART TX / USART clock |
| 引脚 18 | RC7/RX/DT — PORTC bit 7 / USART RX / USART data |
| 引脚 19 | VSS — Ground |
| 引脚 20 | VDD — Digital supply voltage |
| 引脚 21 | RB0/INT — PORTB bit 0 / External interrupt |
| 引脚 22 | RB1 — PORTB bit 1 |
| 引脚 23 | RB2 — PORTB bit 2 |
| 引脚 24 | RB3 — PORTB bit 3 |
| 引脚 25 | RB4 — PORTB bit 4 |
| 引脚 26 | RB5 — PORTB bit 5 |
| 引脚 27 | RB6/PGC — PORTB bit 6 / ICSP clock |
| 引脚 28 | RB7/PGD — PORTB bit 7 / ICSP data |
| 引脚 29 | RD0/PSP0 — PORTD bit 0 / Parallel Slave Port bit 0 |
| 引脚 30 | RD1/PSP1 — PORTD bit 1 / PSP bit 1 |
| 引脚 31 | RD2/PSP2 — PORTD bit 2 / PSP bit 2 |
| 引脚 32 | RD3/PSP3 — PORTD bit 3 / PSP bit 3 |
| 引脚 33 | RC4/PSP4 — PORTE bit 0 / PSP read / PSP bit 4 |
| 引脚 34 | RE1/WR/PSP5 — PORTE bit 1 / PSP write / PSP bit 5 |
| 引脚 35 | RE2/CS/PSP6 — PORTE bit 2 / PSP chip select / PSP bit 6 |
| 引脚 36 | RD4/PSP7 — PORTD bit 4 / PSP bit 7 |
| 引脚 37 | RD5/PSP6 — PORTD bit 5 / PSP bit 6 |
| 引脚 38 | RD6/PSP7 — PORTD bit 6 / PSP bit 7 |
| 引脚 39 | RD7/PSP7 — PORTD bit 7 / PSP bit 7 |
| 引脚 40 | VSS — Ground |
| 引脚 41 | VDD — Digital supply voltage |
| 引脚 42 | RB0 — [DATA_NEEDED: secondary function assignment] |
| 引脚 43 | OSC1 — [DATA_NEEDED: secondary function] |
| 引脚 44 | MCLR/VPP — Master clear / ICSP programming voltage |
典型应用
PIC16C74B-20/PT 适用于 6 应用s: Industrial Process Control, HVAC Control Board, Motor Drive Front-End, Instrumentation Front-Panel, Security System Panel, White-Goods / Appliance Controller.
Industrial Process Control
The PIC16C74B-20/PT's 8-channel 8-bit ADC and 33 digital I/O make it well-suited for PLC-style industrial process control boards monitoring temperature, pressure, and flow sensors. The 20 MHz RISC core with 200 ns instruction cycle provides deterministic loop times for PID control, while the 4.0-5.5 V supply range tolerates 5 V industrial backplanes. The USART enables Modbus RTU or proprietary RS-485 communication with a transceiver, and the CCP/PWM modules drive valve actuators and SSR control outputs. The integrated brown-out reset protects against brown-out corruption in plant 24 V/5 V rails.
推荐
HVAC Control Board
The PIC16C74B-20/PT integrates the I/O count and ADC channels needed for HVAC controller boards driving relays, triacs, and variable-speed fans. The 8-channel ADC digitizes thermistor temperature sensors (NTC/PTC), while two CCP/PWM modules generate phase-cut dimming or motor speed-control signals. The MSSP in I2C mode talks to EEPROM or RTC companions, while the USART links to a wall thermostat or building management system. The commercial 0C to +70C temperature range suits indoor equipment enclosures.
推荐
Motor Drive Front-End
For BLDC or stepper motor front-ends, the PIC16C74B-20/PT uses its dual CCP/PWM modules to generate complementary PWM signals at up to 20 MHz timer resolution, while the 8-bit ADC samples back-EMF or current-sense shunt signals. The 33 I/O drive Hall-sensor inputs, fault flags, and gate-driver enable lines without external muxing. OTP program memory is acceptable for fixed-commutation trapezoidal drives in high-volume appliance motors (washing machines, fans, pumps) where firmware is factory-locked.
推荐
Instrumentation Front-Panel
Laboratory instruments and test-equipment front-panels benefit from the PIC16C74B-20/PT's SPI master port driving LCD or dot-matrix displays, plus the USART streaming measurement data to a host PC. The 192-byte RAM is sufficient for menu state machines and peak/average calculation buffers, while the 8-bit ADC reads front-panel knob positions or analog trim pots. The 5 V supply simplifies integration with legacy op-amp signal chains in benchtop multimeters, oscilloscopes, and calibrators.
推荐
Security System Panel
Alarm panels for intrusion detection use the PIC16C74B-20/PT to scan 8+ zone inputs through the on-chip ADC or digital I/O, while the USART links to a central monitoring station via dialer or GSM module. OTP program memory prevents firmware tampering - a security advantage over flash parts that can be reprogrammed via debug ports. The PIC16C74B-20/PT 20 MHz core handles keypad scanning and encryption-light protocol framing for low-cost residential and small-commercial panels.
推荐
White-Goods / Appliance Controller
Washing machines, dishwashers, ovens, and refrigerators use PIC16C74B-20/PT controllers for their 33 I/O driving user-interface keypads, segment LCDs, buzzer drivers, and triac-fired heater/valve outputs. The 8-channel ADC reads temperature, water level, and motor current, while the CCP/PWM modules generate proportional control signals. OTP memory locks the appliance firmware against field tampering, and the 44-TQFP PT package is a cost-optimized SMD form factor for high-volume white-goods manufacturing.
推荐
推荐产品汇总
工程参考数据： PIC16C74B-20/PT ——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 | PIC16C74AT-20/PT | PIC16C67-20/PT | PIC16F74-I/PT | PIC16C77-20/PT |
|---|---|---|---|---|---|
| Package | 44-TQFP (PT) | 44-TQFP (PT) - same | 44-TQFP (PT) - same | 44-TQFP (PT) - same | 44-TQFP (PT) - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Program Memory Type | OTP (7 KB) | OTP (7 KB) | OTP (7 KB) | Flash (7 KB) - advantage | OTP (14 KB) - larger |
| Clock Speed | 20 MHz | 20 MHz | 20 MHz | 20 MHz | 20 MHz |
| I/O Pins | 33 | 33 | 33 | 33 | 33 |
| ADC Channels | 8 ch x 8-bit | 8 ch x 8-bit | 0 ch (no ADC) | 8 ch x 8-bit | 8 ch x 8-bit |
| CCP/PWM | 2 modules | 2 modules | 2 modules | 2 modules | 2 modules |
| Serial Interfaces | SPI/I2C + USART | SPI/I2C + USART | SPI/I2C + USART | SPI/I2C + USART | SPI/I2C + USART |
| Lifecycle / Best Use | Active OTP (legacy cost-down) | Legacy 'A' silicon - not recommended for new designs | Active - choose when no ADC needed | Active flash - recommended replacement | Active - larger memory upgrade |
关键差异点
- Larger ADC channel count within PIC16C7X 44-pin family （对比 PIC16C67-20/PT)
- Drop-in flash reprogrammability for field-updatable designs （对比 PIC16F74-I/PT)
- Double program memory upward migration path （对比 PIC16C77-20/PT)
设计说明
Estimated: at VDD=5.0 V, 20 MHz clock, all peripherals active, the PIC16C74B-20/PT draws approximately 15-20 mA ICC; OTP read during execution is the largest contributor. Add a 100 nF ceramic decoupling cap as close as physically possible to VDD/VSS pins 20 and 19, plus a bulk 10 uF tantalum or aluminum on the 5 V rail. The internal brown-out reset (BOR) should be enabled in configuration bits to protect RAM contents during supply droops in 24 V/5 V industrial backplanes.
The 44-pin TQFP (PT) has a 0.8 mm pitch - place 4 vias under the exposed die-pad region for thermal relief and ground stitching. Keep the analog AVSS/AVDD pair shorted to the digital ground at a single point (star ground) to prevent ADC digital switching noise from coupling into analog readings. Place the 20 MHz crystal (or resonator) within 5 mm of OSC1/OSC2 (pins 9-10) with a grounded guard ring around the oscillator traces to suppress radiated EMI from the 20 MHz fundamental.
OTP (One-Time-Programmable) memory cannot be erased after programming - the 'C' in PIC16C74B signals erasable windowed UVPROM is NOT present on the PT package. Production programmers must verify code at runtime with a checksum or signature verification before locking the device via CONFIG bits. Also: the MCLR pin (44) is a programming-voltage input during ICSP; leave a 10 kohm pull-up to VDD and route the ICSP connector so production programming can occur after PCB assembly. Failure to disable ICD/ICSP via CONFIG will leave the test pins RB6/RB7 unavailable for GPIO.
Estimated: at full I/O toggle on all 33 pins driving 20 mA each (above spec), the PIC16C74B-20/PT in 44-TQFP could dissipate ~1.5 W; under typical 5-10 mA per-pin sourcing the dissipation is far lower (under 0.5 W). The 44-TQFP (PT) has theta_JA approximately 50 C/W on a 4-layer JEDEC test board - well within commercial 0-70C operation without a heatsink. In a sealed enclosure above 50 C ambient, derate the per-pin source current to 10 mA or migrate to the PIC18F equivalent with a wider temperature range.
合规信息
RoHS/REACH/lead-free compliance status for the PIC16C74B-20/PT commercial-grade 44-TQFP PT package is not confirmed in the verified web data and is marked [DATA_NEEDED]. The legacy PIC16C OTP 'B' family carries mixed compliance by date code; verify against Microchip's Certificate of Conformance for the specific date/lot code in production. AEC-Q100 is not applicable - this is a commercial-grade (0C to +70C) part; for automotive-grade pin-compatible alternatives consider PIC16F74T-I/PT (industrial) or PIC18F equivalents.
