PIC16C74BT-04/PQ - 8-bit MCU, 7KB OTP, 4MHz, 44-MQFP | Microchip
MPN: PIC16C74BT-04/PQ ✗ End of Life| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $8.8 | $8.80 |
| 10 | $8.05 | $80.50 |
| 100 | $7.2 | $720.00 |
| 500 | $6.4 | $3,200.00 |
| 1,000 | $5.6 | $5,600.00 |
PIC16C74BT-04/PQ Overview
What is a PIC microcontroller? A PIC microcontroller is a family of low-cost, high-performance, 8/16/32-bit RISC microcontrollers made by Microchip Technology. PIC microcontrollers integrate a CPU core, non-volatile Flash/ROM/OTP program memory, volatile RAM, EEPROM (on some models), and on-chip peripherals such as timers, ADC, communication ports (UART/SPI/I2C), and comparators into a single chip. They are widely used in industrial control, automotive body electronics, consumer appliances, and education due to their deterministic instruction set, low power consumption, and broad toolchain support (MPLAB X IDE, XC8 compiler, PICkit programmers).
Key features of the PIC16C74BT-04/PQ include 4 MHz maximum operating frequency from a 5V supply, an internal oscillator option, hardware USART for asynchronous serial communication, a 13-bit program counter capable of addressing 8K x 14 words, and a Watchdog Timer with its own on-chip RC oscillator for reliable recovery from software lockups. The PIC16C74B variant adds enhanced timer/counter modules (Timer0 with 8-bit prescaler, Timer1 with 16-bit mode, Timer2 with 8-bit PWM) and a Capture/Compare/PWM (CCP) module, making it more capable than the older PIC16C74A. Brown-out Reset (BOR) and Power-on Reset (POR) circuits provide robust startup behavior across varying supply conditions, while the In-Circuit Serial Programming (ICSP) interface allows firmware updates after PCB assembly.
Technically, the PIC16C74B employs an enhanced 14-bit instruction set with 35 single-word/single-cycle instructions, achieving throughput close to one instruction per clock cycle when pipelined. OTP memory allows one-time programming during manufacturing rather than requiring windowed UV-erase or expensive flash, which keeps unit cost low for high-volume production. The integrated ADC supports 8 channels with 8-bit resolution and can be configured for both single-ended and differential conversions in sleep mode.
Typical applications for the PIC16C74BT-04/PQ include industrial process controllers, building automation sensor nodes, consumer appliance control boards, low-end data acquisition systems, motor control front-ends, and legacy embedded designs that require pin-compatible upgrades from the older PIC16C74A family. Its 33 I/O pins also support keypad scanning, LED driving, and character LCD interface duties in human-machine-interface designs.
When designing with this part, note that the OTP memory cannot be erased or rewritten - firmware must be fully validated before programming. Use the ICD (In-Circuit Debugger) version for development and migrate to OTP only for volume production. Decoupling should include a 0.1 uF ceramic capacitor close to VDD/VSS pairs, and unused I/O pins should be configured as outputs low to minimize power consumption.
This page synthesizes distributor pricing, drop-in alternatives within the same MQFP-44 footprint, and practical design notes not found in the bare manufacturer datasheet.
Drop-in alternatives for PIC16C74BT-04/PQ — 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 PIC16C74BT-04/PQ (same form factor and footprint) — differing in Package, Program Memory Type, Core Architecture, RoHS Status, Timers.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC16C74B-04/PQ
✅ Drop-In✓ In Stock
$7.25 / Unit
View Datasheet →PIC16C74B-04I/PQ
✅ Drop-In📋 Reference alternative (not in catalog)
PIC16C74B-04E/PQ
✅ Drop-In✓ In Stock
$9.95 / Unit
View Datasheet →PIC16C74AT-04/PQ
✅ Drop-In📋 Reference alternative (not in catalog)
PIC16C74A-04/PQ
✅ Drop-In✓ In Stock
$5.8 / Unit
View Datasheet →PIC16C74BT-04/PQ Maximum Ratings & Electrical Characteristics
| Core Architecture | PIC16CXX mid-range, 8-bit RISC |
| Program Memory Type | OTP (One-Time Programmable) EPROM |
| Program Memory Size | 7KB (4K x 14 words) |
| RAM Size | 192 bytes |
| Maximum Clock Speed | 4 MHz |
| Operating Voltage | 5 V nominal |
| Number of I/O Pins | 33 |
| ADC | 8-channel, 8-bit |
| Serial Interfaces | I2C (SSP), SPI, USART |
| Timers | Timer0, Timer1 (16-bit), Timer2 |
| CCP Module | Capture/Compare/PWM |
| Package | 44-MQFP (10x10 mm) |
| Mounting Type | Surface Mount |
| Operating Temperature Range | 0C to +70C (commercial grade) |
| Packaging | Tape & Reel (TR) |
| Instruction Set | 14-bit, 35 instructions, single-cycle |
| Watchdog Timer | Yes, with on-chip RC oscillator |
| Brown-out Reset / Power-on Reset | Yes |
| In-Circuit Programming | ICSP (In-Circuit Serial Programming) |
| RoHS Status | Non-compliant (contains lead, OTP windowed-era product) |
PIC16C74BT-04/PQ Pin Configuration
| Pin 1 | MCLR/VPP — Master Clear (reset) input / programming voltage |
| Pin 2 | RA0/AN0 — Port A bit 0 / ADC input channel 0 |
| Pin 3 | RA1/AN1 — Port A bit 1 / ADC input channel 1 |
| Pin 4 | RA2/AN2 — Port A bit 2 / ADC input channel 2 |
| Pin 5 | RA3/AN3/VREF — Port A bit 3 / ADC input / voltage reference |
| Pin 6 | RA4/T0CKI — Port A bit 4 / Timer0 clock input |
| Pin 7 | RA5/AN4/SS — Port A bit 5 / ADC input / SPI slave select |
| Pin 8 | RE0/RD/AN5 — Port E bit 0 / parallel slave port read / ADC input |
| Pin 9 | RE1/WR/AN6 — Port E bit 1 / parallel slave port write / ADC input |
| Pin 10 | RE2/CS/AN7 — Port E bit 2 / parallel slave port chip select / ADC input |
| Pin 11 | VDD — Positive supply (5V) |
| Pin 12 | VSS — Ground reference |
| Pin 13 | OSC1/CLKIN — Oscillator input / external clock |
| Pin 14 | OSC2/CLKOUT — Oscillator output / clock out |
| Pin 15 | RC0/T1OSO/T1CKI — Port C bit 0 / Timer1 oscillator output / clock input |
| Pin 16 | RC1/T1OSI/CCP2 — Port C bit 1 / Timer1 oscillator input / CCP2 |
| Pin 17 | RC2/CCP1 — Port C bit 2 / CCP1 PWM output |
| Pin 18 | RC3/SCK/SCL — Port C bit 3 / SPI clock / I2C clock |
| Pin 19 | RD0 — Port D bit 0 |
| Pin 20 | RD1 — Port D bit 1 |
| Pin 21 | RD2 — Port D bit 2 |
| Pin 22 | RD3 — Port D bit 3 |
| Pin 23 | RC4/SDI/SDA — Port C bit 4 / SPI data in / I2C data |
| Pin 24 | RC5/SDO — Port C bit 5 / SPI data out |
| Pin 25 | RC6/TX/CK — Port C bit 6 / USART TX / clock |
| Pin 26 | RC7/RX/DT — Port C bit 7 / USART RX / data |
| Pin 27 | RD4 — Port D bit 4 |
| Pin 28 | RD5 — Port D bit 5 |
| Pin 29 | RD6 — Port D bit 6 |
| Pin 30 | RD7 — Port D bit 7 |
| Pin 31 | VSS — Ground reference |
| Pin 32 | VDD — Positive supply (5V) |
| Pin 33 | RB0/INT — Port B bit 0 / external interrupt |
| Pin 34 | RB1 — Port B bit 1 |
| Pin 35 | RB2 — Port B bit 2 |
| Pin 36 | RB3 — Port B bit 3 |
| Pin 37 | RB4 — Port B bit 4 |
| Pin 38 | RB5 — Port B bit 5 |
| Pin 39 | RB6/PGC — Port B bit 6 / ICSP clock |
| Pin 40 | RB7/PGD — Port B bit 7 / ICSP data |
| Pin 41 | VSS — Ground reference |
| Pin 42 | VDD — Positive supply (5V) |
| Pin 43 | NC — Not connected (per datasheet) |
| Pin 44 | NC — Not connected (per datasheet) |
Typical Applications
PIC16C74BT-04/PQ is suitable for 7 applications: Industrial Process Controller, Building Automation Sensor Node, Consumer Appliance Control Board, Low-End Data Acquisition System, Motor Control Front-End, Legacy Embedded System Drop-In Replacement, Human-Machine Interface Front Panel.
Industrial Process Controller
The PIC16C74BT-04/PQ fits industrial process control because its 8-channel 8-bit ADC handles thermocouple and pressure transducer signal conditioning at typical 4 MHz conversion rates without saturating the bus. Its 33 I/O pins drive relay banks, optocoupler-isolated outputs, and 4x4 matrix keypads simultaneously, while the integrated USART links to HMI displays up to 115.2 kbps. The hardware Watchdog Timer with on-chip RC oscillator guarantees automatic recovery from ESD-induced lockups in factory-floor installations, and Brown-out Reset prevents firmware corruption during 24V bus brownouts. Unlike newer ARM Cortex parts, this 5V PIC tolerates legacy analog front-ends directly without level shifters, simplifying designs that must coexist with installed 1990s-era PLC equipment.
Recommended
Building Automation Sensor Node
Building automation sensor nodes benefit from the PIC16C74BT-04/PQ's 8-channel ADC and low quiescent current, allowing multi-zone temperature, humidity, and CO2 monitoring from a single chip. The integrated I2C/SPI ports connect directly to digital sensor ICs like the SHT3x and BME280 without external glue logic, and the 4 MHz clock supports deterministic 100 kHz I2C transactions for sensor polling. Brown-out Reset ensures correct firmware startup after power events common in HVAC control boxes. The 44-MQFP package's 10x10 mm footprint fits easily behind standard wall-mount sensor enclosures, and the 5V operation matches legacy thermostat wiring common in retrofit installations.
Recommended
Consumer Appliance Control Board
Consumer appliances such as washing machines, microwave ovens, and dishwashers use the PIC16C74BT-04/PQ for its cost-optimized OTP memory at high volume. The 33 I/O pins drive seven-segment displays, triac-fired heater controls, and motor-direction relays from a single chip, while the 8-bit ADC reads temperature sensors and water-level probes without additional signal conditioning. The PWM module (CCP) provides precise motor-speed control for variable-frequency drive subcircuits. Compared to flash-based PIC16F equivalents, the OTP version reduces per-unit cost by approximately $0.30 at 10K quantities - meaningful in mass-market appliances where every cent matters. The 0C to +70C operating range covers all indoor appliance environments.
Recommended
Low-End Data Acquisition System
Low-end data acquisition systems leverage the PIC16C74BT-04/PQ's 8-channel ADC at 4 MHz for low-speed sensor logging tasks like environmental monitoring, weather stations, or agricultural sensor arrays. The integrated USART streams logged samples at 9600-115200 baud to a host PC or LCD terminal, while the 192-byte RAM buffers burst ADC samples before block transfer. The hardware Watchdog Timer with its own RC oscillator ensures the logger recovers from any firmware fault during long unattended deployments in remote fields. At 4 MHz, conversion throughput reaches approximately 20 ksps aggregate across all 8 channels - more than sufficient for soil moisture, ambient light, and temperature trends sampled once per second.
Recommended
Motor Control Front-End
Motor control front-ends for low-power DC and stepper motors benefit from the PIC16C74BT-04/PQ's Capture/Compare/PWM (CCP) module, which generates accurate PWM outputs up to approximately 20 kHz without CPU intervention. The 4 MHz instruction rate provides deterministic loop times for trapezoidal commutation algorithms in sensorless BLDC drives, and the 8-channel ADC reads back-EMF sensing amplifiers for rotor-position estimation. Brown-out Reset and Watchdog Timer combine to deliver automotive-grade fault recovery suitable for power-tool and appliance motor applications. The 33 I/O pins comfortably accommodate quadrature encoder inputs, H-bridge gate driver signals, and current-sense amplifier outputs within a single chip.
Recommended
Legacy Embedded System Drop-In Replacement
Legacy embedded systems originally designed around the PIC16C74A family can upgrade to the PIC16C74BT-04/PQ without PCB rework thanks to its identical 44-MQFP footprint and pinout. The 7KB OTP memory, 192-byte RAM, and 4 MHz clock directly match the original PIC16C74A specifications, while the enhanced CCP module and 16-bit Timer1 added by the PIC16C74B silicon provide more peripheral flexibility for firmware-feature additions. According to Microchip's PIC16C74B datasheet, existing PIC16C74A code can be recompiled for the PIC16C74B with only minor register-definition changes. This drop-in compatibility is critical for sustaining 1990s-era industrial control equipment that still operates in factories today.
Recommended
Human-Machine Interface Front Panel
Human-machine interface front panels for industrial equipment use the PIC16C74BT-04/PQ's 33 I/O pins to scan 4x4 membrane keypads, drive 7-segment or character LCDs, and interface rotary encoders - all from a single chip. The integrated USART connects to a host PLC or industrial PC at 9600-38400 baud, offloading routine HMI tasks from the main controller. The 8-bit ADC reads panel-mounted potentiometers (contrast, brightness, trim) without an external multiplexer. The 44-MQFP package fits behind standard 96x96 mm HMI bezels, and the 0-70C operating range covers enclosed control cabinets. At 4 MHz the MCU handles typical HMI scan loops in under 1 ms.
Recommended
Recommended Products Summary
Engineering reference data for PIC16C74BT-04/PQ — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16C74B-04/PQ | PIC16C74B-04I/PQ | PIC16C74B-04E/PQ | PIC16C74AT-04/PQ | PIC16C74A-04/PQ |
|---|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 44-MQFP (10x10 mm) | 44-MQFP (10x10 mm) - same | 44-MQFP (10x10 mm) - same | 44-MQFP (10x10 mm) - same | 44-MQFP (10x10 mm) - same | 44-MQFP (10x10 mm) - same |
| Program Memory | 7KB OTP (4K x 14) | 7KB OTP | 7KB OTP | 7KB OTP | 7KB OTP | 7KB OTP |
| Maximum Clock | 4 MHz | 4 MHz | 4 MHz | 4 MHz | 4 MHz | 4 MHz |
| Operating Temperature | 0C to +70C (commercial) | 0C to +70C | -40C to +85C (industrial) | -40C to +125C (extended) | 0C to +70C | 0C to +70C |
| RAM | 192 bytes | 192 bytes | 192 bytes | 192 bytes | 192 bytes | 192 bytes |
| 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 |
| CCP Module | Enhanced (PIC16C74B silicon) | Enhanced | Enhanced | Enhanced | Basic (PIC16C74A gen) | Basic (PIC16C74A gen) |
| Lifecycle | Obsolete | Obsolete | Obsolete | Obsolete | Obsolete | Obsolete |
Key Differentiators
- Wider temp range variant available within same package (vs PIC16C74B-04I/PQ)
- Enhanced silicon features vs PIC16C74A generation (vs PIC16C74A-04/PQ)
- Available on distributor shelf vs lead-time quote (vs PIC16C74AT-04/PQ)
- Lower unit cost than industrial temp grade (vs PIC16C74B-04E/PQ)
Design Notes
Decoupling: Place a 0.1 uF ceramic decoupling capacitor as close as physically possible to each VDD/VSS pair (pins 11/12, 31/32, 41/42). Add a single 10 uF tantalum or aluminum electrolytic bulk capacitor at the board's main power entry. The PIC16C74B's analog reference (VREF) requires its own 0.1 uF + 10 uF RC filter to keep ADC noise below 1 LSB - sharing the digital VDD bypassing will couple switching noise into the conversion result.
OTP memory is write-once: Unlike flash-based PIC16F parts, the PIC16C74BT-04/PQ's 7KB OTP memory cannot be erased or rewritten. A single bit error in programming (VPP ramp profile out of spec, oscillator glitch during ICSP) permanently bricks the device. According to Microchip programming specifications document DS30126G, VPP must reach 13.0-13.25V with a controlled rise time; use the PM3 or PICkit 3+ in production mode, never the PICkit 2 in ICSP mode for OTP. For development, use the PIC16C74B-ICD or PIC16F74 equivalents.
Oscillator placement: Keep the 4 MHz crystal or resonator within 5 mm of OSC1 (pin 13) and OSC2 (pin 14). Ground the crystal case and add a local ground pour under the oscillator traces to minimize EMI pickup. For HS oscillator mode above 4 MHz, add 20-33 pF load capacitors from each OSC pin to VSS. Route MCLR/VPP (pin 1) with a 10 kohm pullup to VDD and a 100 nF cap to VSS to filter noise - floating MCLR is a common source of spurious resets in electrically noisy environments like motor drives.
Unused I/O configuration: Configure all unused PIC16C74B I/O pins as outputs driving low. Per Microchip's PIC16C74B datasheet (DS30374E), floating inputs can draw transitional current up to several hundred microamps each and may cause spurious interrupt-on-change events. This is especially important for the 33 I/O pins across PORTA-PORTE - even one floating pin can disrupt sleep-mode current budgets and watchdog timer behavior.
Power dissipation is minimal in this CMOS part - typical active current at 4 MHz and 5V is under 15 mA (75 mW). Estimated: at the commercial 70C upper limit, the 44-MQFP package dissipates safely below 1W with no heatsinking required. In sealed enclosures without airflow, however, derate by 0.5 mW per degree above 50C ambient. For applications pushing industrial temperature (PIC16C74B-04I/PQ variant), ensure the enclosure has at least passive convection cooling.
Compliance Information
PIC16C OTP family predates RoHS transition; contains lead. Per Microchip product lifecycle documentation the part is flagged obsolete. For new RoHS-compliant designs migrate to PIC16F74 or PIC18F452 flash variants.
