PIC16C74B-20I/PQ - 8-Bit 20MHz OTP MCU 7KB Flash | Microchip
料号： PIC16C74B-20I/PQ ✗ 停产| 数量 | 单价 | 小计 |
|---|---|---|
| 1 | $11.65 | $11.65 |
| 10 | $10.49 | $104.90 |
| 100 | $9.32 | $932.00 |
| 500 | $8.16 | $4,080.00 |
| 1,000 | $7 | $7,000.00 |
PIC16C74B-20I/PQ 概述
An OTP microcontroller is a class of microcontroller whose program memory is implemented as one-time-programmable EPROM, allowing a single firmware write during production. Within the broader PIC architecture taxonomy, OTP MCUs sit below flash-based MCUs (e.g., PIC16F) but above mask-ROM parts in flexibility, making them ideal for low-to-medium volume embedded products where production cost outweighs in-field reprogrammability needs. The PIC16C74B-20I/PQ is part of Microchip's legacy mid-range lineup targeted at industrial control, instrumentation, and embedded communication designs.
Key differentiating features include 8 channels of 8-bit Analog-to-Digital conversion, two 8-bit timers plus one 16-bit timer, 2 capture/compare/PWM modules, a synchronous serial port configurable as 3-wire SPI or 2-wire I2C, and a USART for asynchronous serial communications. The 25 mA high sink/source current per I/O allows direct driving of LEDs, relays, and small solenoids without external buffers, simplifying BOM and reducing board area in cost-sensitive designs.
Architecturally, the PIC16C74B-20I/PQ employs Microchip's advanced Harvard RISC architecture with a 14-bit instruction word and an 8-bit data path. The device executes most instructions in a single 200 ns cycle at 20 MHz oscillator input, providing deterministic throughput that simplifies real-time control loops. The integrated brown-out reset, watchdog timer, and power-on reset support robust embedded operation without external supervisory components.
Typical applications include industrial automation controllers, motor control subsystems, sensor signal conditioning, embedded serial communication bridges, and low-cost consumer appliances. The wide operating voltage range of 2.5V to 6.0V plus low-power standby of 1 uA typical at 3V/32 kHz make the device suitable for battery-backed or energy-conscious installations.
When designing with this part, note that OTP memory cannot be erased in-circuit - firmware must be fully validated before programming. Engineers typically migrate to flash-based PIC16F74 (drop-in compatible) or PIC18F equivalents for prototypes and low-volume production, reserving OTP PIC16C74B for high-volume runs where per-unit cost dominates.
This page synthesizes distributor pricing, drop-in PIC16C/PIC16F alternatives, and practical design notes not found in the manufacturer datasheet alone.
直接替换替代料： PIC16C74B-20I/PQ ——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-20I/PQ （相同外形与封装尺寸） ——差异在于 Operating Temperature, Package, Serial Interfaces, Mounting Type, Timers.
快速对比工具——选择替代料号进行并排对比：
PIC16C74B-20I/P
✅ 直接替换 ⚠️ 规格未核验✓ 有现货
$6.78 / 个
查看数据手册 →PIC16C74B-04I/P
✅ 直接替换✓ 有现货
$5.55 / 个
查看数据手册 →PIC16C74B-04I/PQ
✅ 直接替换✓ 有现货
$1.78 / 个
查看数据手册 →PIC16C74B-20/L
✅ 直接替换✓ 有现货
$8.2 / 个
查看数据手册 →PIC16C74A-20I/PQ
✅ 直接替换✓ 有现货
$5.95 / 个
查看数据手册 →PIC16F74-I/PQ
✅ 直接替换📋 参考替代料（不在目录中）
PIC16C74B-20I/PQ 最大额定值与电气特性
| Core Architecture | PIC16CXX mid-range, 8-bit RISC |
| Instruction Set | 35 single-word instructions, 14-bit opcode |
| Program Memory | 7 KB (4K x 14) OTP EPROM |
| RAM | 192 bytes |
| Data EEPROM | Not present |
| Maximum CPU Frequency | 20 MHz |
| Instruction Cycle Time | 200 ns at 20 MHz |
| Operating Voltage Range | 2.5 V to 6.0 V |
| Digital I/O Pins | 33 |
| I/O Sink/Source Current | 25 mA / 25 mA per pin |
| ADC | 8 channels, 8-bit resolution |
| Timers | 2 x 8-bit + 1 x 16-bit |
| Capture/Compare/PWM | 2 modules (CCP) |
| Serial Interfaces | 1 x SSP (SPI/I2C), 1 x USART (SCI) |
| 工作温度范围 | -40 C to +85 C (Industrial) |
| 封装 | 44-pin MQFP (10x10 mm) |
| 安装类型 | Surface Mount |
| MSL 等级 | 3 (168 hours) |
| RoHS 状态 | Non-compliant (legacy OTP product) |
| Brown-out Reset | Yes |
| Watchdog Timer | Yes (independent WDT with on-chip RC oscillator) |
| Power-on Reset | Yes |
PIC16C74B-20I/PQ 引脚配置
| 引脚 1 | MCLR/VPP — Master Clear (reset) input / programming voltage |
| 引脚 2 | OSC1/CLKIN — Crystal oscillator input / external clock input |
| 引脚 3 | OSC2/CLKOUT — Crystal oscillator output / clock output |
| 引脚 4 | RA0/AN0 — PORTA bit 0 / analog input 0 |
| 引脚 5 | RA1/AN1 — PORTA bit 1 / analog input 1 |
| 引脚 6 | RA2/AN2 — PORTA bit 2 / analog input 2 |
| 引脚 7 | RA3/AN3/VREF — PORTA bit 3 / analog input 3 / ADC reference voltage |
| 引脚 8 | RA4/T0CKI — PORTA bit 4 / Timer0 clock input |
| 引脚 9 | RA5/AN4/SS — PORTA bit 5 / analog input 4 / SPI slave select |
| 引脚 10 | RE0/RD/AN5 — PORTE bit 0 / read control / analog input 5 |
| 引脚 11 | RE1/WR/AN6 — PORTE bit 1 / write control / analog input 6 |
| 引脚 12 | RE2/CS/AN7 — PORTE bit 2 / chip select / analog input 7 |
| 引脚 13 | VDD — Positive supply voltage |
| 引脚 14 | VSS — Ground reference |
| 引脚 15 | RC0/T1OSO/T1CKI — PORTC bit 0 / Timer1 oscillator output / Timer1 clock input |
| 引脚 16 | RC1/T1OSI/CCP2 — PORTC bit 1 / Timer1 oscillator input / CCP2 I/O |
| 引脚 17 | RC2/CCP1 — PORTC bit 2 / CCP1 I/O |
| 引脚 18 | RC3/SCK/SCL — PORTC bit 3 / SPI clock / I2C clock |
| 引脚 19 | RC4/SDI/SDA — PORTC bit 4 / SPI data in / I2C data |
| 引脚 20 | RC5/SDO — PORTC bit 5 / SPI data out |
| 引脚 21 | RC6/TX/CK — PORTC bit 6 / USART async transmit / sync clock |
| 引脚 22 | RC7/RX/DT — PORTC bit 7 / USART async receive / sync data |
| 引脚 23 | VSS — Ground reference |
| 引脚 24 | VDD — Positive supply voltage |
| 引脚 25 | RB0/INT — PORTB bit 0 / external interrupt input |
| 引脚 26 | RB1 — PORTB bit 1 |
| 引脚 27 | RB2 — PORTB bit 2 |
| 引脚 28 | RB3 — PORTB bit 3 |
| 引脚 29 | RB4 — PORTB bit 4 |
| 引脚 30 | RB5 — PORTB bit 5 |
| 引脚 31 | RB6/PG — PORTB bit 6 / programming clock |
| 引脚 32 | RB7/PG — PORTB bit 7 / programming data |
| 引脚 33 | VSS — Ground reference |
| 引脚 34 | VDD — Positive supply voltage |
| 引脚 35 | RD0 — PORTD bit 0 |
| 引脚 36 | RD1 — PORTD bit 1 |
| 引脚 37 | RD2 — PORTD bit 2 |
| 引脚 38 | RD3 — PORTD bit 3 |
| 引脚 39 | RD4 — PORTD bit 4 |
| 引脚 40 | RD5 — PORTD bit 5 |
| 引脚 41 | RD6 — PORTD bit 6 |
| 引脚 42 | RD7 — PORTD bit 7 |
| 引脚 43 | VSS — Ground reference |
| 引脚 44 | VDD — Positive supply voltage |
典型应用
PIC16C74B-20I/PQ 适用于 6 应用s: Industrial Automation Controllers, Embedded Serial Communication Bridges, Consumer Appliance Control Boards, Automotive Body and Comfort Electronics, Battery-Powered Sensor Monitoring, Test and Measurement Instrumentation.
Industrial Automation Controllers
The PIC16C74B-20I/PQ's 20 MHz instruction rate (5 MIPS) and 7 KB OTP program memory make it well-suited to industrial PLC and motor control subsystems. The 8-channel 8-bit ADC provides direct sensor interface for temperature, pressure, and current monitoring, while two CCP modules deliver hardware PWM for triac/IGBT phase-angle or DC motor speed control. The 25 mA I/O sink/source current directly drives optocouplers and relay coils without external buffers, reducing BOM in 24V industrial signal chains. The 192-byte RAM accommodates small protocol state machines, and the integrated USART plus SSP supports RS-485 and SPI I/O expansion to remote I/O racks. The industrial -40C to +85C temperature range plus brown-out reset and watchdog timer meet IEC 61131-2 environmental requirements for factory-floor equipment.
推荐
Embedded Serial Communication Bridges
The PIC16C74B-20I/PQ integrates both a USART (asynchronous SCI) and an SSP configurable as SPI master/slave or I2C, making it ideal for protocol-conversion gateways between RS-232/RS-485 and fieldbus peripherals. The 33 I/O pins and 7 KB program memory allow full protocol stack implementations including Modbus RTU framing and checksum computation. The 200 ns instruction cycle at 20 MHz sustains 115,200 bps UART throughput with margin for interrupt-driven packet handling. The 192-byte RAM holds multiple receive/transmit buffers, while the 8 ADC channels enable simultaneous analog telemetry alongside serial traffic. The wide 2.5V to 6.0V operating range supports direct interface to both 3.3V and 5V transceivers, simplifying multi-voltage bridge designs.
推荐
Consumer Appliance Control Boards
The PIC16C74B-20I/PQ's OTP memory and high-volume cost-effectiveness suit washing machines, microwave ovens, and HVAC thermostat controllers where per-unit BOM cost dominates over field reprogrammability. The 8 ADC channels read thermistors, humidity sensors, and water-level probes; two CCP modules generate zero-cross triac triggers and brushless DC motor commutation. The 25 mA I/O drives LED status indicators and small relays directly, while the USART interfaces with inverter modules and IR receivers. The 1 uA typical standby current at 3V/32 kHz supports battery-backed clock and timer functions during power-off, and the watchdog timer plus brown-out reset protect against motor-induced supply transients in white goods.
推荐
Automotive Body and Comfort Electronics
Although the PIC16C74B-20I/PQ is not AEC-Q100 qualified, its industrial -40C to +85C range and high-noise-immunity CMOS design make it a common choice for non-safety automotive body modules such as seat controllers, mirror adjusters, and ambient lighting drivers. The 8 ADC channels read position potentiometers and current-sense shunts; two CCP modules generate PWM for mirror actuators and LED dimming. The USART interfaces with body control modules over LIN or K-line protocols via external transceivers. The 7 KB OTP memory holds calibration tables for seat position memory and LED brightness curves. Engineers targeting AEC-Q100 should migrate to qualified PIC18F equivalents for production, but the PIC16C74B remains useful for prototype and pre-production validation.
推荐
Battery-Powered Sensor Monitoring
The PIC16C74B-20I/PQ's low-power 1 uA typical standby at 3V/32 kHz suits battery-backed environmental sensor loggers and remote telemetry units. The 8 ADC channels monitor multiple analog sensors including temperature, humidity, and battery voltage with 8-bit resolution sufficient for trend logging. The integrated brown-out reset protects against battery end-of-life discharge, while the watchdog timer guards against firmware lockup during unattended deployment. The 192-byte RAM buffers sample blocks between transmission events, and the USART wakes periodically to transmit over a connected radio module. The 2.5V to 6.0V operating range supports 3.3V lithium and 4.5V to 6V alkaline battery stacks without additional regulation.
推荐
Test and Measurement Instrumentation
The PIC16C74B-20I/PQ's combination of 8 ADC channels, 2 CCP modules, and dual serial ports enables bench-top instruments like multimeters, signal generators, and lab automation controllers. The 25 mA I/O drive current directly powers seven-segment LED displays and small keypads without external drivers, while the USART outputs measurement data to PCs over USB-to-UART bridges. The 7 KB OTP memory stores calibration constants and linearization tables, and the 33 I/O pins handle display multiplexing plus rotary encoder inputs. The watchdog timer ensures unattended test runs recover from glitches, and the brown-out reset preserves measurement integrity during AC line glitches in lab environments.
推荐
推荐产品汇总
工程参考数据： PIC16C74B-20I/PQ ——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 | PIC16C74B-04I/PQ | PIC16C74B-20/L | PIC16F74-I/PQ |
|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | MQFP-44 | MQFP-44 | MQFP-44 | MQFP-44 |
| Program Memory | 7 KB OTP | 7 KB OTP | 7 KB OTP | 7 KB Flash |
| RAM | 192 bytes | 192 bytes | 192 bytes | 192 bytes |
| Maximum CPU Frequency | 20 MHz | 4 MHz | 20 MHz | 20 MHz |
| Temperature Range | -40C to +85C (Industrial) | -40C to +85C (Industrial) | 0C to +70C (Commercial) | -40C to +85C (Industrial) |
| ADC Channels | 8 x 8-bit | 8 x 8-bit | 8 x 8-bit | 8 x 8-bit |
| Memory Type | OTP EPROM (one-time) | OTP EPROM | OTP EPROM | Flash (reprogrammable) |
| Lifecycle Status | NRND | NRND | NRND | Active |
关键差异点
- Higher speed grade (20 MHz) for real-time control （对比 PIC16C74B-04I/PQ)
- Industrial temperature range for harsh environments （对比 PIC16C74B-20/L)
- Larger program memory for complex firmware （对比 PIC16C74A-20I/PQ)
- OTP cost advantage in high volume （对比 PIC16F74-I/PQ)
设计说明
The PIC16C74B-20I/PQ operates from 2.5V to 6.0V. Place a 100 nF decoupling capacitor as close as possible to each VDD/VSS pair (the device has multiple VDD pins at 13, 24, 34, 44 and corresponding VSS pins at 14, 23, 33, 43). Add a 10 uF bulk capacitor at the board entry point to suppress motor and relay transients. The internal brown-out reset triggers at approximately 4.0V on the falling edge, which can be disabled in configuration but is recommended for industrial deployments. Estimated: with all 33 I/O at 25 mA DC, total supply current reaches approximately 800 mA peak; design traces to handle this or limit I/O count.
OTP EPROM memory cannot be erased or rewritten once programmed - any firmware bug is permanent and cannot be patched. Always prototype with the flash-based PIC16F74-I/PQ (same pinout, same peripherals) before committing to OTP programming for production. Verify all configuration bits (watchdog enable, brown-out, oscillator mode, code protection) before final programming since they cannot be changed later. Programming voltage on MCLR/VPP must reach 13V nominal during EPROM write; ensure your programmer supports the 30430D device ID and PIC16CXX OTP algorithm.
The MQFP-44 package has 0.8 mm pin pitch requiring careful PCB layout. Use 0.4 mm wide traces between pads with no less than 0.2 mm clearance; consider microvia-in-pad if routing four signal layers is unavoidable. Place the crystal within 5 mm of OSC1/OSC2 pins with guard traces connected to ground, and route the MCLR/VPP line away from high-frequency switching nodes to prevent in-circuit reset during EMI events. Keep analog input traces (RA0-RA5, RE0-RE2) short and away from digital switching signals; add a ground pour around the ADC region.
The PIC16C74B-20I/PQ in MQFP-44 has thermal resistance theta_JA of approximately 50 C/W on a standard JEDEC 4-layer test board. At maximum 20 MHz operation with all peripherals active, the device dissipates approximately 200 mW internally, giving a junction temperature rise of about 10 C above ambient. For sealed enclosures with no airflow, derate CPU frequency if ambient exceeds 70 C, or add thermal vias beneath the exposed die pad region if the PCB design accommodates them.
合规信息
Legacy OTP product predates RoHS lead-free conversion; not qualified to AEC-Q100 automotive standard. For RoHS-compliant drop-in, use PIC16F74-I/PQ. REACH compliance maintained per Microchip substance declarations.
