PIC16C74AT-04E/PQ - 8-Bit 4MHz OTP MCU 44-MQFP | Microchip
MPN: PIC16C74AT-04E/PQ ✗ End of Life| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $8.5 | $8.50 |
| 10 | $7.65 | $76.50 |
| 100 | $6.8 | $680.00 |
| 500 | $6.12 | $3,060.00 |
| 1,000 | $5.44 | $5,440.00 |
PIC16C74AT-04E/PQ Overview
What is an 8-bit OTP microcontroller? An OTP (One-Time-Programmable) microcontroller is a type of embedded MCU whose program memory can be written exactly once at production or pre-production time, after which the bit pattern is permanent. Unlike flash-based MCUs, OTP parts cannot be erased or rewritten, making them cost-optimized for high-volume fixed-code applications such as appliance controllers, automotive sub-modules, and industrial sensor interfaces. The PIC16C74AT sits within the broader taxonomy of: microcontroller -> embedded controller -> semiconductor -> integrated circuit.
Key feature highlights include an integrated 8-channel, 8-bit Analog-to-Digital Converter (ADC), three hardware timers (Timer0, Timer1, Timer2), a Capture/Compare/PWM (CCP) module, and a Universal Synchronous/Asynchronous Receiver-Transmitter (USART) port. Brown-out Reset, Power-on Reset, and a Watchdog Timer provide robust supply and code-flow supervision. The 4MHz maximum oscillator speed yields a 1 MIPS instruction throughput at 4MHz, sufficient for sensor sampling and motor control loops.
The PIC16C74AT-04E/PQ uses Microchip's mature mid-range 14-bit instruction set with a Harvard architecture, separating program and data buses for deterministic single-cycle instruction execution. The OTP memory cell uses EPROM technology, packaged in a windowless MQFP suitable for surface-mount assembly.
Typical applications include industrial control panels, HVAC actuator controllers, automotive body and comfort modules, and consumer white-goods main boards. The wide supply and temperature ranges allow use in 5V regulated industrial buses.
When designing with this MCU, ensure the oscillator circuit matches the 4MHz specification and place decoupling capacitors within 5mm of each power pin. OTP memory must be programmed by a certified device programmer before final PCB assembly - field firmware updates are not possible on this part.
This page synthesizes distributor pricing, drop-in alternatives, and practical design notes not found in the standalone manufacturer datasheet.
Drop-in alternatives for PIC16C74AT-04E/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 PIC16C74AT-04E/PQ (same form factor and footprint) — differing in Package, Program Memory Size, Timers, Core Architecture, Operating Temperature Range.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC16C74AT-04/PQ
✅ Drop-In✓ In Stock
$7.2 / Unit
View Datasheet →PIC16C74A-04/PQ
✅ Drop-In✓ In Stock
$5.8 / Unit
View Datasheet →PIC16C74A-04I/P
✅ Drop-In✓ In Stock
$7.5 / Unit
View Datasheet →PIC16C74A-10/PQ
✅ Drop-In✓ In Stock
$5.85 / Unit
View Datasheet →PIC16C74A-10I/P
✅ Drop-In✓ In Stock
$4.95 / Unit
View Datasheet →PIC16C74A-10E/PQ
✅ Drop-In✓ In Stock
$8.7 / Unit
View Datasheet →PIC16C74A-20/PQ
✅ Drop-In✓ In Stock
$6.1 / Unit
View Datasheet →PIC16C74A-20E/PQ
✅ Drop-In✓ In Stock
$8.4 / Unit
View Datasheet →PIC16C74AT-04E/PQ Maximum Ratings & Electrical Characteristics
| Series | PIC 16C |
| Core Processor | PIC |
| Core Size | 8-Bit |
| Maximum Clock Speed | 4 MHz |
| Program Memory Size | 7 KB (4K x 14) OTP |
| RAM Size | 192 x 8 bytes |
| Number of I/O Pins | 33 |
| Package / Case | 44-MQFP (10x10 mm) |
| Supply Voltage (Vcc/Vdd) | 4 V to 6 V |
| Operating Temperature | -40C to +125C |
| ADC | 8-channel, 8-bit |
| Connectivity | I2C, SPI, UART/USART |
| Peripherals | Brown-out Detect/Reset, POR, PWM, WDT |
| Oscillator Type | External |
| Mounting Type | Surface Mount |
PIC16C74AT-04E/PQ Pin Configuration
| Pin 1 | MCLR/VPP — Master Clear (reset) input / programming voltage |
| Pin 2 | OSC1/CLKI — Oscillator input / external clock input |
| Pin 3 | OSC2/CLKO — Oscillator output / clock output |
| Pin 4 | RA0/AN0 — PORTA bit 0 / analog channel 0 |
| Pin 5 | RA1/AN1 — PORTA bit 1 / analog channel 1 |
| Pin 6 | RA2/AN2 — PORTA bit 2 / analog channel 2 |
| Pin 7 | RA3/AN3/VREF — PORTA bit 3 / analog channel 3 / ADC reference voltage |
| Pin 8 | RA4/T0CKI — PORTA bit 4 / Timer0 clock input |
| Pin 9 | RA5/AN4/SS — PORTA bit 5 / analog channel 4 / SPI slave select |
| Pin 10 | VSS — Ground reference |
| Pin 11 | VDD — Positive supply voltage |
| Pin 12 | RB0/INT — PORTB bit 0 / external interrupt |
| Pin 13 | RB1 — PORTB bit 1 |
| Pin 14 | RB2 — PORTB bit 2 |
| Pin 15 | RB3 — PORTB bit 3 |
| Pin 16 | RB4 — PORTB bit 4 |
| Pin 17 | RB5 — PORTB bit 5 |
| Pin 18 | RB6/PGC — PORTB bit 6 / ICSP clock |
| Pin 19 | RB7/PGD — PORTB bit 7 / ICSP data |
| Pin 20 | VSS — Ground reference |
| Pin 21 | VDD — Positive supply voltage |
| Pin 22 | RC0/T1OSO/T1CKI — PORTC bit 0 / Timer1 oscillator output / Timer1 clock input |
| Pin 23 | RC1/T1OSI/CCP2 — PORTC bit 1 / Timer1 oscillator input / CCP2 |
| Pin 24 | RC2/CCP1 — PORTC bit 2 / CCP1 (PWM/capture/compare) |
| Pin 25 | RC3/SCK/SCL — PORTC bit 3 / SPI clock / I2C clock |
| Pin 26 | RC4/SDI/SDA — PORTC bit 4 / SPI data in / I2C data |
| Pin 27 | RC5/SDO — PORTC bit 5 / SPI data out |
| Pin 28 | RC6/TX/CK — PORTC bit 6 / USART transmit / USART clock |
| Pin 29 | RC7/RX/DT — PORTC bit 7 / USART receive / USART data |
| Pin 30 | VSS — Ground reference |
| Pin 31 | VDD — Positive supply voltage |
| Pin 32 | RD0 — PORTD bit 0 |
| Pin 33 | RD1 — PORTD bit 1 |
| Pin 34 | RD2 — PORTD bit 2 |
| Pin 35 | RD3 — PORTD bit 3 |
| Pin 36 | RD4 — PORTD bit 4 |
| Pin 37 | RD5 — PORTD bit 5 |
| Pin 38 | RD6 — PORTD bit 6 |
| Pin 39 | RD7 — PORTD bit 7 |
| Pin 40 | RE0/RD — PORTE bit 0 / parallel slave port read |
| Pin 41 | RE1/WR — PORTE bit 1 / parallel slave port write |
| Pin 42 | RE2/CS — PORTE bit 2 / parallel slave port chip select |
| Pin 43 | VSS — Ground reference |
| Pin 44 | VDD — Positive supply voltage |
Typical Applications
PIC16C74AT-04E/PQ is suitable for 6 applications: Industrial Control Panels, HVAC Actuator Controllers, Automotive Body and Comfort Modules, Consumer White-Goods Main Boards, Sensor Interface Hubs, Security Keypad and Access Controllers.
Industrial Control Panels
The PIC16C74AT-04E/PQ's 8-bit PIC mid-range core and 33 programmable I/O pins provide the headroom required for industrial control panels where multiple sensor inputs and relay outputs must be scanned in deterministic 250 ns instruction cycles at 4 MHz. The integrated 8-channel 8-bit ADC reads panel-mounted potentiometers, temperature transducers, and current-sense shunts without external ADC hardware. Brown-out Detect/Reset and Power-on Reset give robust recovery from 24V industrial bus brown-out events. With 7 KB of OTP program memory, the part fits typical ladder-logic translation and PID loop firmware for motor starters and conveyor interlocks. The 44-MQFP package provides a compact 10x10 mm footprint suitable for DIN-rail-mounted PCB assemblies.
Recommended
HVAC Actuator Controllers
HVAC damper and valve actuators benefit from the PIC16C74AT-04E/PQ's integrated PWM (CCP) module and 192 bytes of SRAM, which provide a closed-loop control surface for driving DC brush motors at variable duty cycles. The 4 MHz oscillator yields 1 MIPS throughput, sufficient for sampled PID loops updating damper position every 100 ms. The 8-channel ADC accepts thermistor and pressure-sensor feedback directly. The -40C to +125C operating range covers rooftop unit enclosures where ambient swings exceed commercial-grade limits. OTP memory locks the production firmware image, eliminating field-reprogramming risk in unattended HVAC plants. The 44-MQFP surface-mount package supports automated pick-and-place on high-volume actuator PCBs.
Recommended
Automotive Body and Comfort Modules
The PIC16C74AT-04E/PQ is well-suited for automotive body controllers handling window lifts, mirror adjust, seat-position memory, and interior lighting. Its 33 I/O pins directly drive relay coils and H-bridge MOSFETs without external logic, while the USART enables LIN-bus communication with body control modules using a small external transceiver. The -40C to +125C industrial temperature window meets under-dash and door-module thermal requirements. The 7 KB OTP memory fits typical body-control state machines (2500-4000 instructions) with margin. The 4 MHz clock provides deterministic timing for window anti-pinch safety algorithms, sampled every 5 ms. Engineers transitioning to production should note that AEC-Q100 qualification is not stated; non-safety body modules are typical applications.
Recommended
Consumer White-Goods Main Boards
The PIC16C74AT-04E/PQ's 7 KB OTP program memory and integrated ADC make it cost-effective for white-goods main boards such as washing-machine controllers, dishwasher user-interface boards, and microwave oven control panels. OTP memory locks firmware permanently, eliminating in-field code tampering and reducing per-unit cost versus flash alternatives. The 4 MHz oscillator and 1 MIPS throughput run scan loops for membrane keypads, LED/LCD segment drives, and buzzer PWM tones. The USART interfaces with inverter boards or display modules. The 44-MQFP package supports high-volume surface-mount assembly. The -40C to +125C temperature rating covers appliance backsplash and motor-compartment thermal stress.
Recommended
Sensor Interface Hubs
Sensor hubs aggregating multiple analog and digital transducers benefit from the PIC16C74AT-04E/PQ's 8-channel 8-bit ADC, three hardware timers, and 33 I/O pins. The MCU can sample up to eight analog sensors (temperature, pressure, humidity, light) at 4 MHz with hardware timer-driven sequencing, then forward digital readings via SPI or I2C to a higher-level host controller. The 192-byte SRAM accommodates small ring buffers for transient data. Brown-out Detect/Reset ensures clean restart on host-side power glitches. The 4 MHz clock and 1 MIPS throughput support modest on-hub pre-processing (linearization, thresholding) without external logic. The 44-MQFP package is well-suited for compact hub assemblies mounted near sensor arrays.
Recommended
Security Keypad and Access Controllers
The PIC16C74AT-04E/PQ provides adequate I/O count (33 pins) and 7 KB OTP for keypad-scanning security panels, RFID reader interfaces, and access-control reader boards. The integrated PWM drives piezo buzzer tone generation for key-press feedback and alarm signals. The Watchdog Timer ensures the controller recovers from code-flow anomalies caused by EMI or supply transients in electrically noisy access-control installations. The USART interfaces with upstream door controllers or wireless modules. OTP memory locks credential-handling firmware to prevent on-board code modification. The 4 MHz instruction rate yields 1 MIPS, sufficient for scanning 4x4 keypads at 10 ms intervals without debounce glitches. The -40C to +125C range supports outdoor reader installations.
Recommended
Recommended Products Summary
Engineering reference data for PIC16C74AT-04E/PQ — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16C74AT-04/PQ | PIC16C74A-04/PQ | PIC16C74A-10/PQ | PIC16C74A-10E/PQ | PIC16C74A-20E/PQ |
|---|---|---|---|---|---|---|
| Package | 44-MQFP (10x10) | 44-MQFP (10x10) | 44-MQFP (10x10) | 44-MQFP (10x10) | 44-MQFP (10x10) | 44-MQFP (10x10) |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Maximum Clock Speed | 4 MHz | 4 MHz | 4 MHz | 10 MHz | 10 MHz | 20 MHz |
| Program Memory | 7 KB OTP | 7 KB OTP | 7 KB OTP | 7 KB OTP | 7 KB OTP | 7 KB OTP |
| RAM Size | 192 bytes | 192 bytes | 192 bytes | 192 bytes | 192 bytes | 192 bytes |
| Number of I/O | 33 | 33 | 33 | 33 | 33 | 33 |
| Operating Temperature | -40C to +125C (industrial 'E') | 0C to +70C (commercial) | 0C to +70C (commercial) | 0C to +70C (commercial) | -40C to +125C (industrial) | -40C to +125C (industrial) |
| Lifecycle Status | Obsolete / NRND | Obsolete / NRND | Obsolete / NRND | Obsolete / NRND | Obsolete / NRND | Obsolete / NRND |
Key Differentiators
- OTP program memory locks firmware permanently, preventing in-field tampering (vs PIC16F74-I/PQ (flash-based successor))
- Wider industrial temperature window than commercial-grade siblings (vs PIC16C74AT-04/PQ (commercial 0C to +70C))
- Lower maximum clock speed rating matches 4 MHz crystal reference designs (vs PIC16C74A-20/PQ (20 MHz max))
Design Notes
Estimated: Power dissipation for the PIC16C74AT-04E/PQ at 4 MHz and 5 V with all 33 I/O pins sourcing 20 mA is approximately 200 mW (40 mA I/O + 25 mA core + 10 mA ADC + peripheral leakage). Place a 100 nF decoupling capacitor within 5 mm of each Vdd pin (44-MQFP has 4 Vdd/Vss pairs: pins 11/10, 21/20, 31/30, 44/43). Bulk decoupling of 10 uF tantalum at the board supply input is recommended. Brown-out Detect should be enabled in configuration fuses to force safe reset when Vdd dips below 4.0 V.
Keep the 4 MHz crystal or ceramic resonator within 10 mm of OSC1 (pin 2) and OSC2 (pin 3) to minimize stray capacitance. Use short, parallel trace routing for the oscillator connections and surround them with a ground pour to suppress noise coupling into the analog reference. Place the MCLR/VPP pull-up resistor (typically 10 kohm) close to pin 1. For In-Circuit Serial Programming (ICSP), dedicate RB6 (PGC) and RB7 (PGD) as ICSP pins - avoid assigning them to high-current loads.
OTP memory programming must occur before final PCB assembly or as a board-level step using a Microchip-certified device programmer (e.g., PICSTART Plus, MPLAB PM3, or ICD-series). Do not assume the part comes pre-programmed - blank OTP parts read as 0x3FFF for every word. Watchdog Timer must be either enabled in fuses and serviced in firmware, or disabled to prevent unintended resets in loops. When migrating to the PIC16F74 flash variant, verify the ADC acquisition time meets 19.5 us minimum for 10-bit conversion; the PIC16C7X 8-bit ADC has slightly different timing.
Compliance Information
Compliance data not present in the verified distributor listings. The part was originally released prior to widespread RoHS transition; the MQFP package historically uses SnPb finish. Verify with Microchip or substitute a flash-based PIC16F74-I/PQ for new RoHS-compliant designs. AEC-Q100 qualification is not stated in the verified data.
