PIC16C74AT-20/PT - 8-Bit 20MHz OTP MCU 7KB | Microchip
MPN: PIC16C74AT-20/PT β End of Life| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $9.2 | $9.20 |
| 10 | $8.45 | $84.50 |
| 100 | $7.3 | $730.00 |
| 500 | $6.4 | $3,200.00 |
| 1,000 | $5.55 | $5,550.00 |
PIC16C74AT-20/PT Overview
Background knowledge: An 8-bit microcontroller (MCU) is a small computer-on-a-chip that combines a CPU, program memory, RAM, and peripherals in a single package. The PIC16C7X family belongs to Microchip's mid-range PIC architecture, sitting between base-line PIC16C5X devices and enhanced PIC17/18 devices. Within the taxonomy MCU -> microcontroller -> embedded processor -> semiconductor, PIC16C7X parts are commonly used for cost-sensitive control applications where deterministic instruction execution and low external component count are priorities. The OTP suffix ('C') denotes EPROM-based one-time programmable memory, which is field-programmable but not electrically erasable, distinguishing it from flash-based PIC16F variants.
Key features include an integrated 8-channel, 8-bit analog-to-digital converter, three timer modules, a synchronous serial port (SSP) supporting SPI and I2C, a USART with addressable transmit/receive buffer, a parallel slave port, and a watchdog timer with on-chip RC oscillator. The device operates from 4.0 V to 6.0 V across the commercial 0C to +70C temperature range and supports in-circuit serial programming (ICSP) via two pins.
Architecturally, the PIC16C7X employs a 14-bit instruction word with a single accumulator (W) and an 8-level deep hardware stack, allowing 35 single-word instructions and an instruction cycle equal to four oscillator periods. Brown-out reset, power-on reset, and a wide operating voltage range further improve field robustness. The 20 MHz clock delivers 5 MIPS throughput, sufficient for closed-loop control and modest signal-processing tasks.
Typical applications include industrial automation controllers, automotive body and accessory modules (non-safety), consumer appliance control boards, sensor signal conditioning, and small motor-control subsystems. The integrated ADC and USART simplify designs that must interface with analog sensors and asynchronous serial buses.
When designing with this part, note that the OTP memory cannot be reprogrammed in-circuit; engineering samples should use the windowed (JW) variant for development. Decoupling the VDD/VSS pairs close to the package and following Microchip's recommended oscillator layout are critical for EMI-sensitive environments.
This page synthesizes distributor pricing, pin-compatible family alternatives, and practical design considerations that extend beyond the manufacturer datasheet to accelerate sourcing and design decisions.
Drop-in alternatives for PIC16C74AT-20/PT 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 PIC16C74AT-20/PT (same form factor and footprint) β differing in ADC, Communication Interfaces, Core Architecture, Operating Temperature Range, Package.
Quick Comparison Tool β Select alternative parts for side-by-side comparison:
PIC16C74AT-20I/PT
β Drop-Inβ In Stock
$5.98 / Unit
View Datasheet βPIC16C74A-20/PT
β Drop-Inπ Reference alternative (not in catalog)
PIC16C74A-20I/PT
β Drop-Inπ Reference alternative (not in catalog)
PIC16F74-I/PT
β Drop-Inπ Reference alternative (not in catalog)
PIC16C74AT-10I/PT
β Drop-Inβ In Stock
$5.45 / Unit
View Datasheet βPIC16C74AT-20/PT Maximum Ratings & Electrical Characteristics
| Core Architecture | PIC16 (8-bit RISC) |
| Program Memory Type | EPROM (OTP) |
| Program Memory Size | 7 KB (4K x 14) |
| RAM Size | 192 bytes |
| Maximum CPU Frequency | 20 MHz |
| Instruction Throughput | 5 MIPS |
| Operating Voltage Range | 4.0 V to 6.0 V |
| I/O Pins | 33 |
| ADC | 8-channel, 8-bit |
| Timers | 3 (Timer0, Timer1, Timer2) |
| Communication Interfaces | USART, SSP (SPI/I2C), Parallel Slave Port |
| Watchdog Timer | Yes (on-chip RC oscillator) |
| Brown-out Reset | Yes |
| Operating Temperature Range | 0C to +70C (commercial) |
| Package | 44-pin TQFP (10x10 mm) |
| Mounting Type | Surface Mount |
| Lead-Free / RoHS | Lead-free finish; RoHS compliance status to be confirmed at order |
| ICSP Programming | Yes (2-pin in-circuit serial programming) |
PIC16C74AT-20/PT Pin Configuration
| Pin 1 | OSC1/CLKIN β Oscillator crystal input or external clock input |
| Pin 2 | OSC2/CLKOUT β Oscillator crystal output; in RC mode, 1/4 fOSC clock output |
| Pin 3 | MCLR/VPP β Master clear (reset) input / programming voltage input |
| Pin 4 | RA0/AN0 β PORTA bit 0 / analog input 0 |
| Pin 5 | RA1/AN1 β PORTA bit 1 / analog input 1 |
| Pin 6 | RA2/AN2 β PORTA bit 2 / analog input 2 |
| Pin 7 | RA3/AN3/VREF β PORTA bit 3 / analog input 3 / ADC reference voltage |
| Pin 8 | RA4/T0CKI β PORTA bit 4 / Timer0 clock input (open-drain output) |
| Pin 9 | RA5/AN4/SS β PORTA bit 5 / analog input 4 / SPI slave select |
| Pin 10 | VSS β Ground reference |
| Pin 11 | VDD β Positive supply voltage (4.0 V to 6.0 V) |
| Pin 12 | RB0/INT β PORTB bit 0 / external interrupt input |
| Pin 13 | RB1 β PORTB bit 1 |
| Pin 14 | RB2 β PORTB bit 2 |
| Pin 15 | RB3 β PORTB bit 3 |
| Pin 16 | RB4 β PORTB bit 4 (interrupt-on-change) |
| Pin 17 | RB5 β PORTB bit 5 (interrupt-on-change) |
| Pin 18 | RB6/PGC β PORTB bit 6 / ICSP clock (interrupt-on-change) |
| Pin 19 | RB7/PGD β PORTB bit 7 / ICSP data (interrupt-on-change) |
| Pin 20 | VSS β Ground reference |
| Pin 21 | VDD β Positive supply voltage |
| Pin 22 | RC0/T1OSO/T1CKI β PORTC bit 0 / Timer1 oscillator output / Timer1 clock input |
| Pin 23 | RC1/T1OSI/CCP2 β PORTC bit 1 / Timer1 oscillator input / CCP2 capture/compare/PWM |
| Pin 24 | RC2/CCP1 β PORTC bit 2 / CCP1 capture/compare/PWM |
| Pin 25 | RC3/SCK/SCL β PORTC bit 3 / SPI clock / I2C clock |
| Pin 26 | RC4/SDI/SDA β PORTC bit 4 / SPI data in / I2C data |
| Pin 27 | RC5/SDO β PORTC bit 5 / SPI data out |
| Pin 28 | RC6/TX/CK β PORTC bit 6 / USART transmit / USART clock |
| Pin 29 | RC7/RX/DT β PORTC bit 7 / USART receive / USART data |
| Pin 30 | VSS β Ground reference |
| Pin 31 | VDD β Positive supply voltage |
| Pin 32 | RD0/PSP0 β PORTD bit 0 / parallel slave port bit 0 |
| Pin 33 | RD1/PSP1 β PORTD bit 1 / parallel slave port bit 1 |
| Pin 34 | RD2/PSP2 β PORTD bit 2 / parallel slave port bit 2 |
| Pin 35 | RD3/PSP3 β PORTD bit 3 / parallel slave port bit 3 |
| Pin 36 | RD4/PSP4 β PORTD bit 4 / parallel slave port bit 4 |
| Pin 37 | RD5/PSP5 β PORTD bit 5 / parallel slave port bit 5 |
| Pin 38 | RD6/PSP6 β PORTD bit 6 / parallel slave port bit 6 |
| Pin 39 | RD7/PSP7 β PORTD bit 7 / parallel slave port bit 7 |
| Pin 40 | VSS β Ground reference |
| Pin 41 | VDD β Positive supply voltage |
| Pin 42 | RE0/RD/AN5 β PORTE bit 0 / parallel slave port read control / analog input 5 |
| Pin 43 | RE1/WR/AN6 β PORTE bit 1 / parallel slave port write control / analog input 6 |
| Pin 44 | RE2/CS/AN7 β PORTE bit 2 / parallel slave port chip select / analog input 7 |
Typical Applications
PIC16C74AT-20/PT is suitable for 6 applications: Industrial Automation Controllers, Consumer Appliance Control Boards, Sensor Signal Conditioning Modules, Small Motor Control (Brushed DC, Stepper), Automotive Body and Accessory Modules, Educational and Hobbyist Development.
Industrial Automation Controllers
The PIC16C74AT-20/PT is well-suited to industrial automation control modules such as PLC co-processors, conveyor sorting controllers, and small machine-tool controllers. Its 33 digital I/O lines plus an integrated 8-channel 8-bit ADC allow direct interfacing to digital sensors, push-buttons, relays, and analog transducers (4-20 mA or 0-10 V signals after conditioning). The 20 MHz clock (5 MIPS) easily handles PID loops, encoder decoding, and serial communication with master controllers. The brown-out reset and watchdog timer provide field robustness against brown-outs and software lock-ups. Compared with a discrete logic controller, the part integrates timing, ADC, and USART, reducing BOM count. The commercial 0C to +70C temperature range covers most indoor cabinet environments; choose the I-grade variant for harsh industrial enclosures.
Recommended
Consumer Appliance Control Boards
The PIC16C74AT-20/PT is commonly used in consumer appliances such as washing-machine controllers, microwave oven control boards, dishwasher user-interface modules, and HVAC zone controllers. Its 33 I/O lines drive seven-segment or character LCD displays, scan keypads, control relays or TRIAC drivers, and read thermistors via the on-chip ADC. The integrated USART enables communication with a master inverter or a Wi-Fi/BLE module for smart-appliance features. The OTP memory is sufficient for fixed-function appliance firmware where no field updates are expected, and the 7 KB program memory accommodates reasonable state-machine plus menu-handling code. At 5 MIPS, scan loops complete well within the 10 ms typical refresh requirement for human-interface feedback. The low pin count and small TQFP package allow compact PCB layouts inside appliance chassis.
Recommended
Sensor Signal Conditioning Modules
The PIC16C74AT-20/PT serves as a low-cost digital signal conditioner for multi-channel sensor modules such as environmental monitors (temperature, humidity, light), gas-detector front-ends, and battery-pack monitoring units. The 8-channel 8-bit ADC multiplexes multiple analog sensor outputs with adequate resolution for trend monitoring and threshold alarms. The I2C/SPI SSP connects to digital sensors like the MCP9808 temperature sensor or the ADXL345 accelerometer, while the USART streams data to a host controller or Bluetooth module. At 5 MIPS, simple digital filtering (moving average, hysteresis) executes comfortably between ADC conversions. The OTP memory prevents accidental firmware modification in field-deployed sensor nodes, and the brown-out reset maintains deterministic behavior during battery-low conditions.
Recommended
Small Motor Control (Brushed DC, Stepper)
The PIC16C74AT-20/PT can drive small brushed DC motors and unipolar/bipolar stepper motors in applications such as automatic valves, vending-machine dispensers, and printer paper-feed subsystems. The 20 MHz clock (5 MIPS) supports up to 50 kHz PWM at 10-bit resolution using Timer2, sufficient for smooth DC motor torque control. The 33 I/O pins drive H-bridge gate signals (or external driver ICs like the L293D), accept quadrature encoder feedback on INT pins, and switch direction via discrete logic. The integrated ADC monitors motor current via a sense resistor for stall detection and torque limiting. For stepper control, two output compare/PWM channels generate precise phase timing. The OTP memory is adequate for fixed motor-control profiles and acceleration curves.
Recommended
Automotive Body and Accessory Modules
The PIC16C74AT-20/PT (or its industrial-grade sibling PIC16C74AT-20I/PT) is used in non-safety automotive body controllers such as interior lighting, mirror adjusters, seat-position memory, and accessory timers. The wide operating voltage range (4.0 V to 6.0 V nominal; tolerant of 12 V load-dump spikes with external TVS clamping) and integrated peripherals support direct interfacing with automotive switches, LEDs, and small relays. The ADC reads wiper-position potentiometers and battery voltage for diagnostics, while the USART communicates with a central body controller over LIN or K-line protocols (with an external transceiver). The watchdog timer and brown-out reset improve resilience against cranking transients. Note that the commercial-grade part is not qualified to AEC-Q100 standards; automotive designs should use automotive-qualified successors like the PIC16F74T-I/PT family.
Recommended
Educational and Hobbyist Development
The PIC16C74AT-20/PT is found in university embedded-systems courses and hobbyist projects as a teaching platform for 8-bit microcontroller fundamentals. The 33 I/O pins, integrated ADC, and three timers expose students to peripherals typical of real-world embedded designs without overwhelming complexity. The PIC16C7X instruction set (35 single-word instructions, 14-bit word) is well documented in textbooks and online tutorials. For development, designers use the JW (windowed ceramic) variant of the PIC16C74A for UV-eraseable prototyping and switch to the OTP /PT variant for production. Many low-cost PIC programmers (PICkit 2/3) support ICSP via two pins, enabling in-circuit programming on soldered boards. The TQFP-44 package is breadboard-friendly via breakout boards, making it accessible for student projects.
Recommended
Recommended Products Summary
Engineering reference data for PIC16C74AT-20/PT β comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16C74AT-20I/PT | PIC16C74A-20/PT | PIC16C74A-20I/PT | PIC16F74-I/PT | PIC16C74AT-10I/PT |
|---|---|---|---|---|---|---|
| Package | 44-pin TQFP (PT) | 44-pin TQFP (PT) - same | 44-pin TQFP (PT) - same | 44-pin TQFP (PT) - same | 44-pin TQFP (PT) - same | 44-pin TQFP (PT) - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Program Memory | 7 KB OTP EPROM | 7 KB OTP EPROM | 7 KB OTP EPROM | 7 KB OTP EPROM | 4 KB Flash | 7 KB OTP EPROM |
| Max CPU Frequency | 20 MHz (5 MIPS) | 20 MHz (5 MIPS) | 20 MHz (5 MIPS) | 20 MHz (5 MIPS) | 20 MHz (5 MIPS) | 10 MHz (2.5 MIPS) |
| Operating Temperature | 0C to +70C (commercial) | -40C to +85C (industrial) | 0C to +70C (commercial) | -40C to +85C (industrial) | -40C to +85C (industrial) | -40C to +85C (industrial) |
| ADC | 8-channel, 8-bit | 8-channel, 8-bit | 8-channel, 8-bit | 8-channel, 8-bit | 8-channel, 8-bit | 8-channel, 8-bit |
| RAM Size | 192 bytes | 192 bytes | 192 bytes | 192 bytes | 192 bytes | 192 bytes |
| I/O Pins | 33 | 33 | 33 | 33 | 33 | 33 |
Key Differentiators
- OTP EPROM-based PIC16 mid-range MCU with 5 MIPS throughput (vs PIC16F74-I/PT)
- Commercial temperature grade for indoor consumer and industrial applications (vs PIC16C74AT-20I/PT)
- 20 MHz clock with 5 MIPS instruction throughput (vs PIC16C74AT-10I/PT)
- Integrated 8-channel 8-bit ADC and USART/SSP peripherals (vs PIC16C72 (earlier PIC16C7X family member))
Design Notes
Decouple all four VDD/VSS pin pairs (pins 11/10, 21/20, 31/30, 41/40) with 100 nF ceramic capacitors placed within 3 mm of each pair. Add a bulk 10 uF tantalum or aluminum polymer capacitor at the board power entry. The PIC16C74AT-20/PT is a CMOS device with low average current draw (typically 15-30 mA at 20 MHz and 5 V) but can exhibit brief current spikes up to 100 mA during peripheral activity; adequate bulk capacitance prevents VDD droop that could trigger brown-out reset.
Place the decoupling capacitors, oscillator crystal (or resonator), and MCLR pull-up resistor within 5 mm of the corresponding MCU pins. Keep oscillator traces short and surround them with a ground pour to minimize EMI radiation. For the TQFP-44 package, route the analog inputs (RA0-RA5, RE0-RE2) away from digital switching traces to reduce ADC coupling noise. Place a small RC filter (100 ohm + 100 nF) on AVDD (or on a dedicated analog VDD rail) if ADC accuracy is critical. Avoid running high-current motor or relay traces under the MCU footprint.
The 'C' suffix in PIC16C74 indicates EPROM (OTP) memory that is one-time programmable; any code change requires a new device, which inflates development costs. During prototyping, use the JW (windowed ceramic) variant of PIC16C74A or PIC16F74 and switch to the OTP /PT part for production. Brown-out reset must be enabled in the configuration word to protect against VDD dips during power-down. Ensure MCLR is never left floating - either tie through a 10 kohm pull-up to VDD or, if unused, configure it as an input-only pin via the configuration word.
Compliance Information
RoHS and REACH compliance status must be confirmed at order from Microchip product compliance certificates; the /PT suffix typically indicates lead-free matte-tin finish but specific REACH/RoHS declarations should be requested per lot. The part is NOT AEC-Q100 qualified; for automotive designs use automotive-qualified flash-based successors.