PIC16C74B-20/L - 8-Bit OTP MCU 7KB 20MHz 44-PLCC | Microchip
MPN: PIC16C74B-20/L β Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $12.52 | $12.52 |
| 10 | $11.8 | $118.00 |
| 100 | $10.45 | $1,045.00 |
| 500 | $9.1 | $4,550.00 |
| 1,000 | $8.2 | $8,200.00 |
PIC16C74B-20/L Overview
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.
Drop-in alternatives for PIC16C74B-20/L β same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Variants in this series
Same-series models that are drop-in compatible with PIC16C74B-20/L (same form factor and footprint) β differing in Core Architecture, Operating Temperature, RAM Size, Serial Interfaces.
Quick Comparison Tool β Select alternative parts for side-by-side comparison:
PIC16C74B-04I/L
β Drop-Inπ Reference alternative (not in catalog)
PIC16C74BT-20/L
β Drop-Inπ Reference alternative (not in catalog)
PIC16C74B-20E/L
β Drop-Inπ Reference alternative (not in catalog)
PIC16F74-I/L
β Drop-Inπ Reference alternative (not in catalog)
PIC16C74A-20/L
β Drop-Inπ Reference alternative (not in catalog)
PIC16C74B-20/L Maximum Ratings & Electrical Characteristics
| 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 |
| Package / Case | 44-PLCC (16.59 x 16.59 mm), J-Lead |
| Operating Temperature | 0 C to +70 C (commercial) |
| Mounting Type | Surface Mount |
| ROM Type | One-Time Programmable (OTP) |
| RoHS Status | Compliant |
PIC16C74B-20/L Pin Configuration
| Pin 1 | MCLR/VPP β Master Clear (Reset) input / Programming voltage |
| Pin 2 | RA0/AN0 β PORTA bit 0 / Analog input channel 0 |
| Pin 3 | RA1/AN1 β PORTA bit 1 / Analog input channel 1 |
| Pin 4 | RA2/AN2 β PORTA bit 2 / Analog input channel 2 |
| Pin 5 | RA3/AN3/VREF β PORTA bit 3 / Analog input 3 / ADC reference |
| Pin 6 | RA4/T0CKI β PORTA bit 4 / Timer 0 clock input |
| Pin 7 | RA5/AN4/SS β PORTA bit 5 / Analog 4 / SPI slave select |
| Pin 8 | RE0/RD/AN5 β PORTE bit 0 / Read control / Analog 5 |
| Pin 9 | RE1/WR/AN6 β PORTE bit 1 / Write control / Analog 6 |
| Pin 10 | RE2/CS/AN7 β PORTE bit 2 / Chip select / Analog 7 |
| Pin 11 | VSS β Ground |
| Pin 12 | OSC1/CLKIN β Oscillator input / external clock |
| Pin 13 | OSC2/CLKOUT β Oscillator output / clock out |
| Pin 14 | RC0/T1OSO/T1CKI β PORTC bit 0 / Timer1 oscillator out / clock in |
| Pin 15 | RC1/T1OSI/CCP2 β PORTC bit 1 / Timer1 oscillator in / CCP2 |
| Pin 16 | RC2/CCP1 β PORTC bit 2 / Capture Compare PWM 1 |
| Pin 17 | RC3/SCK/SCL β PORTC bit 3 / SPI clock / I2C clock |
| Pin 18 | RC4/SDI/SDA β PORTC bit 4 / SPI data in / I2C data |
| Pin 19 | RC5/SDO β PORTC bit 5 / SPI data out |
| Pin 20 | RC6/TX/CK β PORTC bit 6 / USART TX / clock |
| Pin 21 | RC7/RX/DT β PORTC bit 7 / USART RX / data |
| Pin 22 | RD0/PSP0 β PORTD bit 0 / Parallel Slave Port bit 0 |
| Pin 23 | RD1/PSP1 β PORTD bit 1 / Parallel Slave Port bit 1 |
| Pin 24 | RD2/PSP2 β PORTD bit 2 / Parallel Slave Port bit 2 |
| Pin 25 | RD3/PSP3 β PORTD bit 3 / Parallel Slave Port bit 3 |
| Pin 26 | RD4/PSP4 β PORTD bit 4 / Parallel Slave Port bit 4 |
| Pin 27 | RD5/PSP5 β PORTD bit 5 / Parallel Slave Port bit 5 |
| Pin 28 | RD6/PSP6 β PORTD bit 6 / Parallel Slave Port bit 6 |
| Pin 29 | RD7/PSP7 β PORTD bit 7 / Parallel Slave Port bit 7 |
| Pin 30 | VSS β Ground |
| Pin 31 | VDD β Positive supply voltage |
| Pin 32 | RB0/INT β PORTB bit 0 / External interrupt |
| Pin 33 | RB1 β PORTB bit 1 |
| Pin 34 | RB2 β PORTB bit 2 |
| Pin 35 | RB3 β PORTB bit 3 |
| Pin 36 | RB4 β PORTB bit 4 |
| Pin 37 | RB5 β PORTB bit 5 |
| Pin 38 | RB6/PGC β PORTB bit 6 / ICSP clock |
| Pin 39 | RB7/PGD β PORTB bit 7 / ICSP data |
| Pin 40 | VSS β Ground (additional) |
| Pin 41 | VDD β Positive supply voltage (additional) |
| Pin 42 | NC β Not connected (per datasheet) |
| Pin 43 | NC β Not connected (per datasheet) |
| Pin 44 | NC β Not connected (per datasheet) |
Typical Applications
PIC16C74B-20/L is suitable for 6 applications: 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.
Recommended
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.
Recommended
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.
Recommended
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.
Recommended
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.
Recommended
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.
Recommended
Recommended Products Summary
Engineering reference data for PIC16C74B-20/L β comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | 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 |
Key Differentiators
- Highest program memory in 44-PLCC PIC16C7x family (vs PIC16C74A-20/L)
- Flash-based reprogrammability (vs PIC16C74B-20/L vs PIC16F74-I/L)
- Industrial temperature grade option available (vs PIC16C74B-20E/L)
Design Notes
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.
Compliance Information
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.
