PIC16C74A-04E/PT - 7KB OTP 8-bit MCU, 33 I/O, 44-TQFP | Microchip
MPN: PIC16C74A-04E/PT β Last Time Buy| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $8.42 | $8.42 |
| 10 | $7.55 | $75.50 |
| 100 | $6.71 | $671.00 |
| 500 | $5.95 | $2,975.00 |
| 1,000 | $5.3 | $5,300.00 |
PIC16C74A-04E/PT Overview
An 8-bit microcontroller is a single-chip computer that integrates a CPU, non-volatile program memory, volatile data memory, and peripherals on one die. PIC16 mid-range MCUs sit in Microchip's 14-bit instruction-word family and target cost-sensitive embedded control with deterministic timing. The PIC16C74A family in particular adds an integrated 8-channel, 8-bit A/D converter, USART, MSSP (SPI/I2C), and Capture/Compare/PWM modules, giving it a richer peripheral set than the smaller PIC16C7X siblings while retaining OTP-only program memory for low unit-cost applications.
Key features include five I/O ports (RA, RB, RC, RD, RE) supporting 25 mA source/sink per pin for direct LED and relay drive, an 8-channel 8-bit ADC with 25 us conversion time, two 8-bit and one 16-bit timers, a hardware USART for asynchronous serial, an MSSP module supporting both SPI and I2C, and brown-out reset plus watchdog timer for field reliability. Wide operating voltage (2.5 V - 6.0 V) and the extended -40 C to +125 C temperature range suit industrial and automotive under-hood environments.
The architecture is a fully-static CMOS design with separate 14-bit program and 8-bit data buses. The Harvard memory layout removes the bus contention that bottlenecks von Neumann MCUs, and the 200 ns instruction cycle at 20 MHz (500 ns at 4 MHz) keeps interrupt latency predictable. The 33 I/O pins are multiplexed with peripheral functions, including analog inputs on PORTA and PORTE, the parallel slave port on PORTD, and the external interrupt on RB0.
Typical applications include industrial motor control front-ends, HVAC sensor interfaces, automotive body controllers, appliance user-interface boards, and legacy embedded designs being refreshed from PIC16C5X or PIC16C6X platforms. The 8-bit ADC and PWM channels make it well suited for closed-loop valve and pump control. Extended-temperature grade makes it attractive for outdoor or under-hood automotive use.
When designing with this device, allocate enough I/O pins early - 33 lines may seem generous but several are shared with oscillator, MCLR, and analog inputs. Use the MCLR pin with the recommended 10 kohm pull-up; floating MCLR causes intermittent resets. The OTP memory means firmware must be right first time, so choose the flash-based PIC16F74 as a drop-in for prototype runs.
This page synthesizes distributor pricing, drop-in alternatives, and practical design notes not found in the manufacturer datasheet - including lifecycle status (Microchip recommends the flash-based PIC16F74 as the active replacement), parametric comparisons, and pin-compatible upgrade paths in both OTP and Flash variants.
Drop-in alternatives for PIC16C74A-04E/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 PIC16C74A-04E/PT (same form factor and footprint) β differing in Package, Program Memory Size, RAM Size, Program Memory Type, Timers.
Quick Comparison Tool β Select alternative parts for side-by-side comparison:
PIC16F74-I/PT
β Drop-Inπ Reference alternative (not in catalog)
PIC16C74A-20E/PT
β Drop-Inπ Reference alternative (not in catalog)
PIC16C74A-04I/PT
β Drop-Inβ In Stock
$5.85 / Unit
View Datasheet βPIC16C74B-04I/PT
β Drop-Inβ In Stock
$6.1 / Unit
View Datasheet βPIC16C67-04E/PT
β Drop-Inβ In Stock
$7.1 / Unit
View Datasheet βPIC16F747-I/PT
β Drop-Inπ Reference alternative (not in catalog)
PIC16C74A-04E/PT Maximum Ratings & Electrical Characteristics
| Program Memory Size | 7 KB (4K x 14) |
| Program Memory Type | OTP (One-Time-Programmable) |
| RAM Size | 192 x 8 bytes |
| EEPROM Data Memory | None (no on-chip EEPROM) |
| Number of I/O Pins | 33 |
| Maximum Clock Frequency | 4 MHz (04 speed grade) |
| Instruction Cycle Time | 1 us at 4 MHz |
| Oscillator Type | External (crystal/ceramic/RC) |
| Operating Voltage Range | 2.5 V to 6.0 V |
| ADC | 8 channels, 8-bit, 25 us conversion (per datasheet) |
| Timers | Two 8-bit (TMR0, TMR2) + one 16-bit (TMR1) |
| Capture/Compare/PWM | 1 CCP module (10-bit PWM) |
| Serial Interfaces | USART + MSSP (SPI / I2C) |
| I/O Source/Sink Current | 25 mA / 25 mA per pin |
| Operating Temperature Range | -40 C to +125 C (Extended, -E suffix) |
| Package | 44-pin TQFP (PT), 10 x 10 mm body |
| Mounting Type | Surface Mount |
| Packaging | Tray |
| RoHS Status | Compliant per Microchip product page |
| Brown-out Reset | Yes (per PIC16C7X family datasheet) |
| Watchdog Timer | Yes (per PIC16C7X family datasheet) |
| Core | PIC16 mid-range, 14-bit instruction word, 8-bit data path |
PIC16C74A-04E/PT Pin Configuration
| Pin 1 | OSC1/CLKI β Oscillator input / external clock input |
| Pin 2 | OSC2/CLKO β Oscillator output / clock output (Fosc/4) |
| Pin 3 | MCLR/VPP β Master clear (active low reset) / 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 voltage reference |
| Pin 8 | RA4/T0CKI β PORTA bit 4 / Timer0 clock input (open-drain) |
| Pin 9 | RA5/AN4/SS β PORTA bit 5 / analog input 4 / SPI slave select |
| Pin 10 | RE0/RD/AN5 β PORTE bit 0 / parallel slave port read / analog input 5 |
| Pin 11 | RE1/WR/AN6 β PORTE bit 1 / parallel slave port write / analog input 6 |
| Pin 12 | RE2/CS/AN7 β PORTE bit 2 / parallel slave port chip select / analog input 7 |
| Pin 13 | VDD β Positive supply (2.5 V to 6.0 V) |
| Pin 14 | VSS β Ground reference |
| Pin 15 | RC0/T1OSO/T1CKI β PORTC bit 0 / Timer1 oscillator output / Timer1 clock input |
| Pin 16 | RC1/T1OSI/CCP2 β PORTC bit 1 / Timer1 oscillator input / CCP2 I/O |
| Pin 17 | RC2/CCP1 β PORTC bit 2 / Capture/Compare/PWM1 output |
| Pin 18 | RC3/SCK/SCL β PORTC bit 3 / MSSP SPI clock / I2C clock |
| Pin 19 | RC4/SDI/SDA β PORTC bit 4 / MSSP SPI data in / I2C data |
| Pin 20 | RC5/SDO β PORTC bit 5 / MSSP SPI data out |
| Pin 21 | RC6/TX/CK β PORTC bit 6 / USART transmit / USART clock |
| Pin 22 | RC7/RX/DT β PORTC bit 7 / USART receive / USART data |
| Pin 23 | VSS β Ground reference (digital) |
| Pin 24 | VDD β Positive supply (digital) |
| Pin 25 | RB0/INT β PORTB bit 0 / external interrupt |
| Pin 26 | RB1 β PORTB bit 1 |
| Pin 27 | RB2 β PORTB bit 2 |
| Pin 28 | RB3/PGM β PORTB bit 3 / LVP programming entry |
| Pin 29 | RB4 β PORTB bit 4 (interrupt-on-change) |
| Pin 30 | RB5 β PORTB bit 5 (interrupt-on-change) |
| Pin 31 | RB6/PGC β PORTB bit 6 / ICSP clock |
| Pin 32 | RB7/PGD β PORTB bit 7 / ICSP data |
| Pin 33 | VSS β Ground reference |
| Pin 34 | VDD β Positive supply |
| Pin 35 | RD0/PSP0 β PORTD bit 0 / parallel slave port bit 0 |
| Pin 36 | RD1/PSP1 β PORTD bit 1 / parallel slave port bit 1 |
| Pin 37 | RD2/PSP2 β PORTD bit 2 / parallel slave port bit 2 |
| Pin 38 | RD3/PSP3 β PORTD bit 3 / parallel slave port bit 3 |
| Pin 39 | RD4/PSP4 β PORTD bit 4 / parallel slave port bit 4 |
| Pin 40 | RD5/PSP5 β PORTD bit 5 / parallel slave port bit 5 |
| Pin 41 | RD6/PSP6 β PORTD bit 6 / parallel slave port bit 6 |
| Pin 42 | RD7/PSP7 β PORTD bit 7 / parallel slave port bit 7 |
| Pin 43 | VSS β Ground reference |
| Pin 44 | VDD β Positive supply |
Typical Applications
PIC16C74A-04E/PT is suitable for 7 applications: Industrial Motor Control Front-End, Automotive Body and HVAC Controllers, Appliance User-Interface Boards, HVAC Sensor and Valve Interface, Legacy Embedded Refresh from PIC16C5X/6X, Smart Sensor Hubs with UART/SPI Uplinks, Power Metering and Energy Monitor Front-End.
Industrial Motor Control Front-End
The PIC16C74A-04E/PT fits motor control front-ends because its 8-channel 8-bit ADC samples up to 8 current/voltage sense channels within 25 us each, well below the typical 1 ms PWM period of a 1 kHz drive loop. The 10-bit CCP/PWM module generates the gate drive reference, and the 25 mA per-pin sink/source drives optocoupler LEDs directly without buffers. Its 2.5 V to 6.0 V supply matches the auxiliary rails commonly available on industrial 24 V systems after regulation. Extended temperature grade -40 C to +125 C tolerates cabinet-ambient rise above 70 C with margin.
Recommended
Automotive Body and HVAC Controllers
The PIC16C74A-04E/PT is qualified for automotive body modules because the -E extended temperature rating -40 C to +125 C covers under-dash and even under-hood locations. The 33 I/O pins directly drive LEDs, relays, and stepper motor coils via 25 mA source/sink, eliminating discrete driver transistors on simple loads. The MSSP and USART link to body-CAN gateways or LIN slaves, while the ADC reads thermistors, potentiometers, and pressure sensors. For new automotive programs, Microchip recommends PIC16F74 with the same 44-TQFP (PT) footprint for firmware updates over CAN UDS.
Recommended
Appliance User-Interface Boards
The PIC16C74A-04E/PT powers washing-machine, dishwasher, and oven UI boards thanks to its 33 I/O pins driving 7-segment displays, matrix keypads, buzzer drivers, and triac optocouplers simultaneously. The OTP program memory is well suited to high-volume cost-down designs where firmware is locked at production. With USART, the MCU talks to inverter boards or smart-meter modules, while the ADC monitors NTC temperature sensors. Extended temperature grade supports oven-control applications where ambient reaches 100 C inside the chassis.
Recommended
HVAC Sensor and Valve Interface
The PIC16C74A-04E/PT handles HVAC sensor aggregation by reading 8 analog inputs (thermistors, humidity transducers, pressure sensors) into its 8-channel ADC, computing setpoint errors, and driving PWM-controlled valves via its CCP module. The MSSP (I2C) interface aggregates remote digital sensors on a 2-wire bus, reducing wiring cost in commercial air handlers. With 192 bytes of RAM and 7 KB OTP, the part supports modest control loops including PI compensation and Modbus RTU over the USART for BMS connectivity.
Recommended
Legacy Embedded Refresh from PIC16C5X/6X
The PIC16C74A-04E/PT is a natural upgrade path from older PIC16C5X and PIC16C6X designs because it shares the PIC mid-range instruction set, allowing existing assembly code to recompile with minimal changes. It offers 4x to 8x more program memory than PIC16C5X (7 KB vs 1-2 KB) and adds peripherals like the 8-channel ADC that earlier devices lacked. The 44-pin TQFP (PT) footprint may force a PCB change, but pinout-compatible 28-pin and 40-pin PIC16C7X variants ease migration of board layouts that need less I/O.
Recommended
Smart Sensor Hubs with UART/SPI Uplinks
The PIC16C74A-04E/PT serves as a sensor hub front-end because its 8-channel ADC and MSSP (SPI) port simultaneously sample analog sensors and read digital sensors like accelerometers. The USART provides an asynchronous uplink to a host processor or radio module at up to 38.4 kbaud at 4 MHz, while the extended temperature grade supports outdoor and industrial enclosures. OTP memory locks calibration constants and protocol stacks, preventing field tampering in metering applications.
Recommended
Power Metering and Energy Monitor Front-End
The PIC16C74A-04E/PT is well suited to single-phase power metering because its 8-channel ADC simultaneously samples line voltage and current CT outputs, while its CCP captures zero-crossings for phase calculation. With 7 KB OTP, the part supports IEC 62053-21 class-1 accuracy algorithms for 50/60 Hz mains, and its USART outputs Modbus or DLMS/COSEM frames to a concentrator. Extended -40 C to +125 C operation handles meter outdoor cabinets in tropical and desert climates.
Recommended
Recommended Products Summary
Engineering reference data for PIC16C74A-04E/PT β comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16F74-I/PT | PIC16C74A-20E/PT | PIC16C74A-04I/PT | PIC16C74B-04I/PT | PIC16C67-04E/PT | PIC16F747-I/PT |
|---|---|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| 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 | 44-pin TQFP (PT) - same |
| Program Memory | 7 KB OTP | 7 KB Flash | 7 KB OTP | 7 KB OTP | 7 KB OTP | 8 KB OTP | 7 KB Flash |
| Max Clock Frequency | 4 MHz | 20 MHz | 20 MHz | 4 MHz | 4 MHz | 4 MHz | 20 MHz |
| RAM Size | 192 bytes | 192 bytes | 192 bytes | 192 bytes | 192 bytes | 368 bytes | 192 bytes |
| Number of I/O Pins | 33 | 33 | 33 | 33 | 33 | 33 | 33 |
| ADC | 8-ch, 8-bit | 8-ch, 8-bit | 8-ch, 8-bit | 8-ch, 8-bit | 8-ch, 8-bit | None (digital only) | 14-ch, 8/10-bit |
| Operating Temperature | -40 C to +125 C (E) | -40 C to +85 C (I) | -40 C to +125 C (E) | -40 C to +85 C (I) | -40 C to +85 C (I) | -40 C to +125 C (E) | -40 C to +85 C (I) |
Key Differentiators
- Same TQFP-44 footprint as flash-based replacement (vs PIC16F74-I/PT)
- Industrial -E temperature grade vs Industrial -I (vs PIC16C74A-04I/PT)
- On-chip 8-channel 8-bit ADC vs digital-only (vs PIC16C67-04E/PT)
- Higher max CPU throughput than 04 grade (vs PIC16C74A-04I/PT)
Design Notes
Place a 100 nF decoupling capacitor within 5 mm of every VDD pin (pins 13, 24, 34, 44) and a 10 uF bulk capacitor near the package to suppress switching transients when the ADC and USART switch simultaneously. The PIC16C74A-04E/PT datasheet recommends tying all four VDD pins together with a star ground; floating one VDD pin can cause ADC reference drift and intermittent brown-out resets under load.
Route the analog inputs RA0-RA5 and RE0-RE2 away from the OSC1/OSC2 traces and the parallel slave port PORTD to minimize digital-to-analog crosstalk. The 8-channel ADC reference is shared on RA3; place a 10 uF + 100 nF capacitor on VREF if you enable external reference mode, otherwise internal reference is recommended. Use a guard ring tied to analog ground around the analog pins when sensing low-level signals.
OTP memory cannot be erased, so PIC16C74A-04E/PT firmware must be 100% verified before programming - a single bug requires scrapping the part. The MCLR pin (pin 3) must have a 10 kohm pull-up to VDD; floating MCLR causes spurious resets during EFT events. Configuration word bit 13 (LVP) must match the programmer mode - leaving LVP enabled when using high-voltage programming can lock the part permanently.
The 25 mA source/sink rating on PORTB and PORTD is for DC drive; high-frequency PWM edges above 10 kHz need series resistors (typically 47-100 ohm) to dampen transmission-line ringing on long PCB traces. USART signals above 38.4 kbaud on a 4 MHz clock require baud-rate-error analysis - the 4 MHz oscillator restricts standard rates to 1200, 2400, 9600, and 19.2 kbaud with zero error; 57.6 kbaud has +2.1% error.
Compliance Information
RoHS compliance per Microchip product page. AEC-Q100 qualification not stated in provided data - the -E (Extended) temperature grade is industrial, not automotive-qualified. Lifecycle status is Last-Time-Buy per Microchip's official product page; recommended replacement is PIC16F74 (Flash). Halogen-free status not stated in verified data.
