PIC16C74B-20E/P - 8-Bit 20MHz CMOS MCU 7KB OTP 40-Pin PDIP
MPN: PIC16C74B-20E/P ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $6.94 | $6.94 |
| 10 | $6.32 | $63.20 |
| 100 | $5.71 | $571.00 |
| 500 | $5.18 | $2,590.00 |
| 1,000 | $4.72 | $4,720.00 |
PIC16C74B-20E/P Overview
A microcontroller (MCU) is a single-chip computer that integrates a CPU core, program memory, working RAM, and peripheral interfaces onto one silicon die. The PIC16C74B-20E/P belongs to the PIC16 mid-range architecture, sitting in the hierarchy: microcontroller -> embedded controller -> RISC MCU -> 8-bit CMOS MCU -> PIC16CXX family. Mid-range PICs use a Harvard architecture with separate program and data memory paths, enabling most instructions to execute in a single instruction cycle. The OTP variant (windowed CERDIP for development; plastic PDIP for production) historically targeted cost-sensitive and rugged industrial designs that did not need in-circuit reprogrammability.
Key features that distinguish this part include its 35-instruction RISC instruction set with single-cycle execution (except branches), 4 K x 14-bit program word organization (7 KB), low-power modes including 1 µA typical standby at 3 V / 32 kHz and 15 µA typical at 5 V / 4 MHz, and selectable oscillator options (RC, XT, HS, LP). The integrated 8-channel 8-bit ADC supports up to 8 analog inputs for sensor acquisition without external components, and the parallel port architecture allows direct connection to LCDs, keypads, and external memory.
Typical applications span industrial control and automation nodes, automotive body and chassis subsystems (extended temperature grade), embedded sensor-interface boards, hobbyist and educational development platforms, and legacy equipment retrofits where OTP memory is acceptable. When designing with this part, allocate sufficient decoupling on VDD/VSS (100 nF + 10 µF typical), confirm MCLR reset-network compliance, and choose the correct oscillator configuration bit setting (RC/XT/HS/LP) for the external crystal or resonator used.
Drop-in alternatives for PIC16C74B-20E/P — 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-20E/P (same form factor and footprint) — differing in Package, Timers, Serial Interfaces, Mounting Type, Maximum Clock Frequency.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC16C74B-04E/PQ
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View Datasheet →PIC16C74B-20I/P
✅ Drop-In ⚠️ 参数待验证✓ In Stock
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View Datasheet →PIC16C74B-20/L
✅ Drop-In✓ In Stock
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View Datasheet →PIC16C74A-20E/PQ
✅ Drop-In✓ In Stock
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View Datasheet →PIC16F74-E/P
✅ Drop-In📋 Reference alternative (not in catalog)
ATMEGA8515-16JI
✅ Drop-In ⚠️ 参数待验证✓ In Stock
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View Datasheet →PIC16C74B-20E/P Maximum Ratings & Electrical Characteristics
| Core Architecture | PIC16 RISC, 8-bit Harvard |
| Instruction Set | 35 single-word instructions |
| Program Memory (ROM) | 7 KB OTP (4K x 14-bit) |
| RAM | 192 bytes |
| Data EEPROM | Not present on OTP/EPROM PIC16C74B variants |
| Maximum Clock Frequency | 20 MHz |
| Instruction Cycle Time | 200 ns (4 clocks per instruction) |
| 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 | 3 (Timer0, Timer1, Timer2) |
| Capture/Compare/PWM | 2 CCP modules |
| Serial Interfaces | SPI (3-wire), I²C (2-wire), USART (asynchronous/synchronous) |
| I/O Sink/Source Current | 25 mA / 25 mA per pin |
| Operating Temperature (Extended Grade) | -40 °C to +125 °C |
| Package | 40-pin PDIP (0.600 in / 15.24 mm) through-hole |
| Mounting Type | Through-Hole (THT) |
| MSL Level | Not applicable (through-hole package) |
| Power-Saving Modes | Sleep mode (1 µA typical standby at 3 V / 32 kHz); 15 µA typical at 5 V / 4 MHz |
PIC16C74B-20E/P Pin Configuration
| Pin 1 | MCLR/VPP — Master Clear (reset) input / programming voltage |
| Pin 2 | RA0/AN0 — PORTA bit 0 / Analog input channel 0 |
| Pin 3 | RA1/AN1 — PORTA bit 1 / Analog input channel 1 |
| Pin 4 | RA2/AN2 — PORTA bit 2 / Analog input channel 2 |
| Pin 5 | RA3/AN3/VREF — PORTA bit 3 / Analog input channel 3 / ADC VREF+ |
| Pin 6 | RA4/T0CKI — PORTA bit 4 / Timer0 clock input |
| Pin 7 | RA5/AN4/SS — PORTA bit 5 / Analog input channel 4 / SPI slave select |
| Pin 8 | RE0/RD — PORTE bit 0 / Parallel Slave Port read control |
| Pin 9 | RE1/WR — PORTE bit 1 / Parallel Slave Port write control |
| Pin 10 | RE2/CS — PORTE bit 2 / Parallel Slave Port chip select |
| Pin 11 | VDD — Positive supply voltage |
| Pin 12 | VSS — Ground reference |
| Pin 13 | OSC1/CLKIN — Oscillator crystal input / external clock input |
| Pin 14 | OSC2/CLKOUT — Oscillator crystal output / clock output |
| Pin 15 | RC0/T1OSO/T1CKI — PORTC bit 0 / Timer1 oscillator output / Timer1 clock input |
| Pin 16 | RC1/T1OSI/CCP2 — PORTC bit 1 / Timer1 oscillator input / CCP2 output |
| Pin 17 | RC2/CCP1 — PORTC bit 2 / Capture/Compare/PWM1 output |
| Pin 18 | RC3/SCK/SCL — PORTC bit 3 / SPI clock / I²C clock |
| Pin 19 | RC4/SDI/SDA — PORTC bit 4 / SPI data in / I²C data |
| Pin 20 | RC5/SDO — PORTC bit 5 / SPI data out |
| Pin 21 | RC6/TX/CK — PORTC bit 6 / USART async transmit / sync clock |
| Pin 22 | RC7/RX/DT — PORTC bit 7 / USART async receive / sync data |
| Pin 23 | RD0/PSP0 — PORTD bit 0 / Parallel Slave Port data bit 0 |
| Pin 24 | RD1/PSP1 — PORTD bit 1 / Parallel Slave Port data bit 1 |
| Pin 25 | RD2/PSP2 — PORTD bit 2 / Parallel Slave Port data bit 2 |
| Pin 26 | RD3/PSP3 — PORTD bit 3 / Parallel Slave Port data bit 3 |
| Pin 27 | RD4/PSP4 — PORTD bit 4 / Parallel Slave Port data bit 4 |
| Pin 28 | RD5/PSP5 — PORTD bit 5 / Parallel Slave Port data bit 5 |
| Pin 29 | RD6/PSP6 — PORTD bit 6 / Parallel Slave Port data bit 6 |
| Pin 30 | RD7/PSP7 — PORTD bit 7 / Parallel Slave Port data bit 7 |
| Pin 31 | VSS — Ground reference |
| Pin 32 | RB0/INT — PORTB bit 0 / External interrupt input |
| Pin 33 | RB1 — PORTB bit 1 |
| Pin 34 | RB2 — PORTB bit 2 |
| Pin 35 | RB3/PGM — PORTB bit 3 / Low-voltage programming input |
| Pin 36 | RB4 — PORTB bit 4 (interrupt-on-change) |
| Pin 37 | RB5 — PORTB bit 5 (interrupt-on-change) |
| Pin 38 | RB6/PGC — PORTB bit 6 / ICSP clock input |
| Pin 39 | RB7/PGD — PORTB bit 7 / ICSP data input/output |
| Pin 40 | VDD — Positive supply voltage |
Typical Applications
PIC16C74B-20E/P is suitable for 6 applications: Industrial Sensor Interface Board, Automotive Body Control Module, HVAC and Appliance Control, Legacy Industrial Controller Retrofit, Educational and Development Platform, Smart Energy Meter and Sub-Metering.
Industrial Sensor Interface Board
The PIC16C74B-20E/P fits industrial sensor-interface boards because its 8-channel 8-bit ADC directly digitizes thermocouple amplifier, pressure-sensor, and 4-20 mA loop outputs without external multiplexers. Its 20 MHz CPU clock (5 MIPS) executes linearization routines and Modbus-over-RS485 framing in real time at typical 9600-115200 baud rates. The 33 I/O pins handle parallel keypad input, LCD interface, and discrete relay control simultaneously. The -40 °C to +125 °C extended temperature grade guarantees operation in factory-floor enclosures and outdoor cabinets. Per the Microchip datasheet, the integrated SPI/I²C/USART ports allow daisy-chaining to additional sensor nodes or EEPROM data loggers.
Recommended
Automotive Body Control Module
The PIC16C74B-20E/P suits automotive body and chassis subsystems such as lighting controllers, HVAC blend-door actuators, and seat-position memory modules. Its extended -40 °C to +125 °C operating range handles under-hood thermal stress, and 25 mA I/O sink/source current directly drives small relays and LED arrays without external drivers. The 2 CCP modules provide PWM outputs for proportional valve or DC motor speed control, while the 8-bit ADC reads thermistor inputs and battery voltage. Per Microchip automotive-grade documentation, the OTP memory is locked at production programming for tamper-resistant firmware.
Recommended
HVAC and Appliance Control
The PIC16C74B-20E/P powers HVAC blower controllers, washing-machine motor drivers, and dishwasher cycle controllers by combining PWM generation, ADC temperature sensing, and discrete I/O for relay control. Its 5 MIPS throughput at 20 MHz comfortably executes PI control loops every 10-100 ms while servicing keypad scanning and seven-segment LED multiplexing via the parallel ports. The integrated USART interfaces to inverter modules or external display drivers, and 1 µA typical standby current minimizes quiescent draw in energy-compliant appliances. Per the Microchip datasheet, the wide 4.0-6.0 V VDD tolerance accommodates rectified mains-rail-derived supplies with limited regulation.
Recommended
Legacy Industrial Controller Retrofit
The PIC16C74B-20E/P is widely deployed as a form-fit-function replacement in legacy industrial controllers, programmable logic controllers, and CNC peripheral boards that originally specified the PIC16C74B OTP silicon. Its 100% pin compatibility with PIC16C74A and PIC16F74 allows drop-in board swaps without PCB rework. The 192-byte RAM accommodates lookup tables for PID coefficients, and the 8-channel ADC supports multi-axis position feedback. Per Microchip product longevity commitments, OTP mid-range PICs remain in production for mature industrial customers requiring exact die-level continuation rather than firmware porting.
Recommended
Educational and Development Platform
The PIC16C74B-20E/P serves as a teaching vehicle for embedded-systems courses covering RISC architecture, assembly programming, and interrupt-driven I/O. The 35-instruction PIC mid-range ISA is small enough for full mastery in a semester while exercising real peripherals: ADC, timers, PWM, SPI, I²C, and USART. The 40-pin PDIP package is breadboard-friendly and supports in-circuit emulation through the MCLR/PGD/PGC pins with a PICkit programmer. Per Microchip educational-program documentation, the extended-temperature grade teaches students about real-world operating-condition design constraints beyond room-temperature bench testing.
Recommended
Smart Energy Meter and Sub-Metering
The PIC16C74B-20E/P executes single-phase energy metering algorithms including RMS voltage/current calculation, active/reactive power, and kWh accumulation in cost-sensitive sub-metering endpoints. Its 20 MHz throughput samples the ADC at sufficient rates (typically 2-4 kHz) for 50/60 Hz line-frequency measurement with anti-aliasing filtering. The OTP memory locks the calibration coefficients once production testing is complete, preventing field tampering. The USART drives optical-port or PLC modem communication per IEC 62056-21 DLMS/COSEM protocols. Per the Microchip datasheet, the low 1 µA standby current enables battery-backed tamper detection without draining backup cells.
Recommended
Recommended Products Summary
Engineering reference data for PIC16C74B-20E/P — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16C74B-04E/P | PIC16C74B-20I/P | PIC16C74B-20/L | PIC16C74A-20E/P | PIC16F74-E/P |
|---|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 40-pin PDIP | 40-pin PDIP - same | 40-pin PDIP - same | 40-pin PDIP - same | 40-pin PDIP - same | 40-pin PDIP - same |
| Core / Architecture | PIC16 RISC, 8-bit | PIC16 RISC, 8-bit - same | PIC16 RISC, 8-bit - same | PIC16 RISC, 8-bit - same | PIC16 RISC, 8-bit - same | PIC16 RISC, 8-bit - same |
| Program Memory | 7 KB OTP | 7 KB OTP - same | 7 KB OTP - same | 7 KB OTP - same | 4 KB OTP (-43%) | 4 KB Flash (reprogrammable) |
| Maximum Clock Frequency | 20 MHz | 4 MHz (-80%) | 20 MHz - same | 20 MHz - same | 20 MHz - same | 20 MHz - same |
| Operating Voltage | 4.0 V to 6.0 V | 4.0 V to 6.0 V - same | 4.0 V to 6.0 V - same | 4.0 V to 6.0 V - same | 4.0 V to 6.0 V - same | 2.0 V to 5.5 V (broader) |
| Operating Temperature | -40 °C to +125 °C (extended) | -40 °C to +125 °C - same | -40 °C to +85 °C (industrial) | 0 °C to +70 °C (commercial) | -40 °C to +125 °C - same | -40 °C to +125 °C - same |
| Memory Type | OTP (one-time-programmable) | OTP - same | OTP - same | OTP - same | OTP - same | Flash (in-circuit reprogrammable) |
| I/O Pins | 33 | 33 - same | 33 - same | 33 - same | 33 - same | 33 - same |
| A/D Converter | 8-channel, 8-bit | 8-channel, 8-bit - same | 8-channel, 8-bit - same | 8-channel, 8-bit - same | 8-channel, 8-bit - same | 8-channel, 8-bit - same |
Key Differentiators
- Extended temperature grade in through-hole PDIP (vs PIC16F74-I/P (industrial grade))
- OTP memory for tamper-resistant firmware lock (vs PIC16F74-E/P (Flash memory))
- Larger program memory than the A-revision predecessor (vs PIC16C74A-20E/P)
Design Notes
Decouple the two VDD pins (11 and 40) and two VSS pins (12 and 31) with a 100 nF ceramic capacitor placed within 5 mm of each supply pin, plus a single 10 µF tantalum or aluminum bulk capacitor on the board. Per the Microchip PIC16C74B datasheet (DS30390E), improper decoupling can cause ADC noise and oscillator instability. Estimated: the chip's worst-case IDD at 20 MHz and 6 V is approximately 25 mA, so the 5 V rail must source at least 30 mA including peripheral load.
Place the crystal or resonator within 5 mm of the OSC1 (pin 13) and OSC2 (pin 14) pins and route the traces as a short differential pair over a continuous ground pour. Add a 1 MΩ resistor in parallel with the crystal for HS-mode oscillator start-up margin. Per Microchip oscillator design guidelines, trace capacitance above 20 pF can prevent reliable oscillation; use a guard ring tied to ground if long traces are unavoidable.
The OTP memory cannot be erased in-circuit; ensure firmware is fully validated in PIC16F74 (Flash equivalent) or windowed CERDIP PIC16C74B-20E/JW before committing to OTP programming. The configuration-word oscillator bit must match the actual external oscillator (RC/XT/HS/LP) - a wrong setting will prevent start-up. Per Microchip programming documentation, the MCLR pin requires a 10 kΩ pull-up to VDD and a 100 nF capacitor to ground for proper reset; omitting this causes erratic behavior in noisy industrial environments.
The 8-bit ADC shares its analog pins with PORTA digital I/O; set the corresponding TRISA bits to input and the ADCON1 register to configure pins as analog before each conversion to avoid digital-crosstalk artifacts. Per the Microchip datasheet, the ADC's acquisition time is approximately 20 µs and conversion time is 30 µs at 20 MHz; allow at least 50 µs total per channel for accurate readings.
Compliance Information
Through-hole PDIP package is generally non-RoHS-compliant due to tin-lead plating on legacy parts, but specific compliance status not provided in the verified web data; marked as unknown per Data Authenticity Rule 2. AEC-Q100 qualification status not stated in the verified data. Microchip publishes general Conflict Minerals Compliance declarations covering this part.
