PIC16C74BT-04/L - 8-Bit 4MHz OTP MCU, 7KB, 44-PLCC | Microchip
MPN: PIC16C74BT-04/L ✗ End of Life| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $8.5 | $8.50 |
| 10 | $7.65 | $76.50 |
| 100 | $6.8 | $680.00 |
| 500 | $5.95 | $2,975.00 |
| 1,000 | $5.2 | $5,200.00 |
PIC16C74BT-04/L Overview
An 8-bit microcontroller (MCU) is a single-chip computer that integrates a CPU, program memory, RAM, and peripherals on one die. Within the broader taxonomy, the PIC16C74B belongs to Microchip's mid-range 8-bit PIC16C family - widely used in industrial control, consumer appliances, and automotive body electronics where deterministic instruction execution and mature CMOS process technology matter more than raw MHz. The 'C' in PIC16C denotes the OTP/EPROM program-memory flavor, while 'B' denotes the silicon revision (B-step). Microcontrollers sit at the foundation of embedded systems, providing programmable intelligence between sensors/actuators and higher-level processors.
Key features include 33 digital I/O pins organized across multiple ports, an integrated 8-channel 8-bit ADC, two 8-bit timers plus one 16-bit timer/counter, a Universal Synchronous/Asynchronous Receiver Transmitter (USART/SCI), and a Synchronous Serial Port (SSP/SPI/I2C). The CMOS, low-power RISC-VIII variant runs from a 5 V rail and supports a commercial 0 °C to +70 °C operating range for benign environments, while a fully-static core architecture enables power-down drivers and reduces quiescent draw - characteristics suited to commissioning industrial control modules requiring deterministic interrupt handling.
Technically, the PIC16C14B uses a Harvard memory bus, a 14-bit shared bus with 35-level shared instruction bus, and a 4-stage pipeline bus design. Functionally, the PIC16C14B uses a Harvard organization with a 14-bit instruction bus and a shared 8-bit data bus; it executes 35 shared instructions at 4 clock bus/cycle, providing deterministic interrupt handling.
Typical applications include industrial control panels, white-goods and consumer appliances, HVAC thermostats, and automotive body controllers requiring deterministic code execution through in-system reprogramming. The wide peripheral availability includes standard CMOS peripherals suitable for direct injection, supporting direct interfaces to sensors and industrial actuators.
When designing with this part, design a robust decoupling strategy using two common decoupling capacitors on the supply pins, and design a stable 5 V supply pin regulator - critical for the industrial control modules requiring deterministic timing in automotive firmware.
Drop-in alternatives for PIC16C74BT-04/L — 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/L (same form factor and footprint) — differing in Operating Temperature, Core Architecture, Mounting Type, Timers, ADC.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC16C74B-04I/L
✅ Drop-In✓ In Stock
$2.61 / Unit
View Datasheet →PIC16C74BT-04I/L
✅ Drop-In✓ In Stock
$4.33 / Unit
View Datasheet →PIC16C74B-04/L
✅ Drop-In✓ In Stock
$3.32 / Unit
View Datasheet →PIC16C74B-20I/L
✅ Drop-In✓ In Stock
$8.92 / Unit
View Datasheet →PIC16C74B-20/L
✅ Drop-In✓ In Stock
$8.2 / Unit
View Datasheet →PIC16C74B-04E/L
✅ Drop-In✓ In Stock
$9.3 / Unit
View Datasheet →PIC16C74B-04I/P
✅ Drop-In✓ In Stock
$5.55 / Unit
View Datasheet →PIC16C74BT-04/L Maximum Ratings & Electrical Characteristics
| Product Type | 8-bit Microcontroller (MCU) |
| Family | PIC16CXX (PIC16 mid-range, OTP/PROM) |
| Core | RISC, 8-bit data bus, 14-bit instruction bus |
| CPU Speed | 4 MHz |
| Program Memory | 7 KB (4K x 14) OTP PROM |
| RAM | 192 bytes (192 x 8) |
| I/O Pins | 33 |
| Package | 44-PLCC (J-lead), 16.59 x 16.59 mm |
| Mounting Type | Surface Mount |
| Supply Voltage | 5 V (typical) |
| Operating Temperature | 0 °C to +70 °C (Commercial) |
| ADC | 8-channel x 8-bit (integrated) |
| Timers | Timer0 (8-bit), Timer1 (16-bit), Timer2 (8-bit) |
| Communication | USART/SCI, SSP/SPI/I2C |
| Instruction Set | 35 instructions, 4 clock/instruction cycle |
| Architecture | Harvard, fully static CMOS |
| Temperature Grade | Commercial (0 °C to +70 °C) |
PIC16C74BT-04/L Pin Configuration
| Pin 1 | MCLR/VPP — Master Clear (Reset) input / Programming voltage input |
| 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 / Voltage reference |
| Pin 6 | RA4/T0CKI — PORTA bit 4 / Timer0 clock input |
| Pin 7 | RA5/AN4/SS — PORTA bit 5 / Analog input channel 4 / SSP slave select |
| Pin 8 | RE0/RD/AN5 — PORTE bit 0 / Read control for parallel slave port / Analog input 5 |
| Pin 9 | RE1/WR/AN6 — PORTE bit 1 / Write control for PSP / Analog input 6 |
| Pin 10 | RE2/CS/AN7 — PORTE bit 2 / Chip select for PSP / Analog input 7 |
| Pin 11 | VDD — Positive supply voltage (5 V) |
| Pin 12 | VSS — Ground reference |
| Pin 13 | OSC1/CLKIN — Oscillator input / External clock input |
| Pin 14 | OSC2/CLKOUT — Oscillator 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 PWM |
| Pin 17 | RC2/CCP1 — PORTC bit 2 / CCP1 PWM output |
| Pin 18 | RC3/SCK/SCL — PORTC bit 3 / SSP clock (SPI/I2C) |
| Pin 19 | RC4/SDI/SDA — PORTC bit 4 / SSP data in / I2C data |
| Pin 20 | RC5/SDO — PORTC bit 5 / SSP data out |
| Pin 21 | RC6/TX/CK — PORTC bit 6 / USART transmit / USART clock |
| Pin 22 | RC7/RX/DT — PORTC bit 7 / USART receive / USART data |
| Pin 23 | RD0/PSP0 — PORTD bit 0 / Parallel slave port bit 0 |
| Pin 24 | RD1/PSP1 — PORTD bit 1 / Parallel slave port bit 1 |
| Pin 25 | RD2/PSP2 — PORTD bit 2 / Parallel slave port bit 2 |
| Pin 26 | RD3/PSP3 — PORTD bit 3 / Parallel slave port bit 3 |
| Pin 27 | RD4/PSP4 — PORTD bit 4 / Parallel slave port bit 4 |
| Pin 28 | RD5/PSP5 — PORTD bit 5 / Parallel slave port bit 5 |
| Pin 29 | RD6/PSP6 — PORTD bit 6 / Parallel slave port bit 6 |
| Pin 30 | RD7/PSP7 — PORTD bit 7 / Parallel slave port bit 7 |
| Pin 31 | VSS — Ground reference |
| Pin 32 | VDD — Positive supply voltage (5 V) |
| Pin 33 | RB0/INT — PORTB bit 0 / External interrupt input |
| Pin 34 | RB1 — PORTB bit 1 |
| Pin 35 | RB2 — PORTB bit 2 |
| Pin 36 | RB3 — PORTB bit 3 |
| Pin 37 | RB4 — PORTB bit 4 |
| Pin 38 | RB5 — PORTB bit 5 |
| Pin 39 | RB6/PGC — PORTB bit 6 / ICSP clock |
| Pin 40 | RB7/PGD — PORTB bit 7 / ICSP data |
| Pin 41 | NC — Not connected (per datasheet) |
| Pin 42 | NC — Not connected (per datasheet) |
| Pin 43 | NC — Not connected (per datasheet) |
| Pin 44 | NC — Not connected (per datasheet) |
Typical Applications
PIC16C74BT-04/L is suitable for 6 applications: Industrial Control Panels, White Goods & Consumer Appliances, HVAC Thermostat Controllers, Automotive Body Controllers, Security & Access-Control Panels, Power Supply Monitoring & Smart Battery Chargers.
Industrial Control Panels
The PIC16C74BT-04/L's 33 digital I/O pins, 8-channel 8-bit ADC, and 5 V CMOS operation make it well-suited for industrial control panels requiring deterministic firmware. The 7 KB OTP memory holds ladder-logic-replacement routines for relay drivers, push-button debouncers, and indicator-LED multiplexers. The 4 MHz CPU executes 35 single-cycle instructions at 250 ns per instruction, fast enough for 1 kHz PID loops on motor-control valves. Designers benefit from the integrated USART for RS-485 half-duplex networking between distributed control panels. The 192-byte RAM is sufficient for stack, scratchpad, and a small protocol buffer, allowing drop-in integration into legacy industrial-control designs that need a reliable, long-lifecycle MCU.
Recommended
White Goods & Consumer Appliances
The PIC16C74BT-04/L's mature CMOS, low-power design suits white-goods consumer appliances such as washing machines, dishwashers, and microwave ovens. The integrated 8-bit ADC reads thermistor temperature sensors and water-level switches, while the PWM-capable Timer2 drives motor-control triacs and buzzer tones. The 7 KB OTP holds appliance state machines, EEPROM-emulation routines, and fault-log buffers. The fully-static core lets the MCU enter sleep mode between user inputs, dropping quiescent current to microamp levels for energy-efficient standby. The 44-PLCC J-lead package withstands the thermal-cycling stresses of household appliance environments while supporting both surface-mount and socketed mounting.
Recommended
HVAC Thermostat Controllers
The PIC16C74BT-04/L is well-suited to HVAC thermostat controllers where the 33 I/O pins drive multi-segment LCDs, keypad matrices, and triac-switched furnace/AC stages. The integrated ADC reads NTC thermistors at sub-Hz sample rates, while the USART interfaces with split-system indoor/outdoor communication links. The 7 KB OTP stores fuzzy-logic setpoint curves and adaptive-learning schedules for energy savings. Designers rely on programmed operation of the integrated SSR versus built-in SSR, supporting direct interfaces to temperature sensors and triac actuators. The 4 MHz CPU supports 100 Hz sample rates for room-temperature averaging while leaving cycles for keypad scanning and LCD refresh.
Recommended
Automotive Body Controllers
The PIC16C74BT-04/L supports legacy automotive body controllers for interior lighting, door modules, and seat-position memories, where its 33 digital I/O drive multiple relay coils and PWM-bright LED arrays. The integrated SSP supports SPI communication with body-control ASICs and CAN-transceiver ICs at 1 Mbps. The 7 KB OTP holds LIN-bus slave stacks and diagnostic-trouble-code storage for service-shop retrieval. The industrial-temperature -04I variant is required for under-dash automotive deployments with -40 °C cold-start and +85 °C roof-line summer heat. The 44-PLCC J-lead package with 16.59 mm body fits legacy automotive PCBs designed before QFN migration became standard.
Recommended
Security & Access-Control Panels
The PIC16C74BT-04/L is ideal for security and access-control panels with 33 I/O ports, 8-channel ADC, and USART for keypad, RFID reader, and alarm-siren integration. The 7 KB OTP stores encrypted credential tables, alarm-event logs, and intrusion-detection state machines. The integrated timers generate precise pulse-width modulation for magnetic-stripe readers and piezo-buzzer alarm tones. The fully-static CMOS core enables battery-backed sleep modes, drawing under 1 microamp during armed-quiescent states for multi-year operation on a single 9 V backup battery. The 44-PLCC package supports socketed mounting on legacy security panels for fast field replacement.
Recommended
Power Supply Monitoring & Smart Battery Chargers
The PIC16C74BT-04/L fits smart battery charger and DC power supply monitoring boards where the 8-channel ADC monitors battery voltage, charge current, and cell temperature, while the PWM-capable Timer2 drives synchronous-rectifier MOSFET gate drivers. The 7 KB OTP holds multi-stage charge profiles (Li-Ion CC-CV, NiMH delta-peak, lead-acid equalization) and coulomb-counting firmware. The integrated USART outputs charge-status telemetry to a host display or logging PC. Designers design a robust decoupling strategy using two common decoupling capacitors on the supply pins, designing a stable 5 V supply pin regulator. The 4 MHz CPU executes ADC scans at 10 kHz while leaving cycles for state-machine updates.
Recommended
Recommended Products Summary
Engineering reference data for PIC16C74BT-04/L — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16C74B-04I/L | PIC16C74BT-04I/L | PIC16C74B-04/L | PIC16C74B-20I/L | PIC16C74B-20/L | PIC16C74B-04E/L | PIC16C74B-04I/P |
|---|---|---|---|---|---|---|---|---|
| Package | 44-PLCC (J-lead) | 44-PLCC - same | 44-PLCC - same | 44-PLCC - same | 44-PLCC - same | 44-PLCC - same | 44-PLCC - same | 44-PLCC - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| CPU Speed | 4 MHz | 4 MHz | 4 MHz | 4 MHz | 20 MHz | 20 MHz | 4 MHz | 4 MHz |
| Program Memory | 7 KB OTP | 7 KB OTP | 7 KB OTP | 7 KB OTP | 7 KB OTP | 7 KB OTP | 7 KB OTP | 7 KB OTP |
| Operating Temperature | 0 °C to +70 °C (Commercial) | -40 °C to +85 °C (Industrial) | -40 °C to +85 °C (Industrial) | 0 °C to +70 °C (Commercial) | -40 °C to +85 °C (Industrial) | 0 °C to +70 °C (Commercial) | -40 °C to +125 °C (Extended) | -40 °C to +85 °C (Industrial) |
| Packing Method | Tape & Reel | Tube | Tape & Reel | Tube | Tube | Tube | Tube | Tube |
| Lifecycle Status | Obsolete | Obsolete | Obsolete | Obsolete | Obsolete | Obsolete | Obsolete | Obsolete |
| ADC | 8 ch x 8-bit | 8 ch x 8-bit | 8 ch x 8-bit | 8 ch x 8-bit | 8 ch x 8-bit | 8 ch x 8-bit | 8 ch x 8-bit | 8 ch x 8-bit |
| I/O Pins | 33 | 33 | 33 | 33 | 33 | 33 | 33 | 33 |
Key Differentiators
- Industrial -40 °C to +85 °C temperature option with identical 44-PLCC pinout (vs PIC16C74B-04I/L)
- 5x faster CPU option (20 MHz vs 4 MHz) in same package (vs PIC16C74B-20I/L)
- Extended -40 °C to +125 °C option for automotive and outdoor deployments (vs PIC16C74B-04E/L)
Design Notes
Decouple both VDD pins (11 and 32) with two common decoupling capacitors - a 100 nF ceramic for high-frequency noise and a 10 µF electrolytic for low-frequency bulk filtering - placed within 5 mm of each supply pin. The PIC16C74BT-04/L draws up to 30 mA at 4 MHz/5 V with all peripherals active, so total rail current must be sized accordingly. Estimated: at VDD=5V, IDD=20mA typical, the two-pin pair carries 40mA; a 5V LDO with at least 100 mA headroom is recommended.
Do not skip the configuration resistor on MCLR/VPP (pin 1) - the datasheet specifies a pull-up to VDD through 10-50 kΩ for normal operation, with a path to VPP (typically 13.25 V) during programming. Floating MCLR causes spurious resets or unreliable startup. For in-circuit serial programming (ICSP), isolate the MCLR pull-up from any external reset supervisor with a small signal diode or resistor network.
The PIC16C74BT-04/L's fully-static CMOS core allows the clock to be stopped in software, but when using an external crystal or resonator on OSC1/OSC2 (pins 13-14), keep the trace length under 10 mm and surround the oscillator with a ground pour. Series resistors (10-100 Ω) on each oscillator pin can dampen over-shoot from fast edges. If using the internal RC oscillator, the ADC accuracy depends on stable VDD; add a 100 nF ceramic bypass adjacent to the VREF pin.
Estimated: the 44-PLCC package has a theta_JA of approximately 35 °C/W. At 30 mA active current and 5 V supply, internal dissipation is roughly 150 mW, resulting in a 5.3 °C junction temperature rise above ambient - well within the commercial 0 °C to +70 °C operating range. For the extended -04E variant operating up to +125 °C, the same dissipation raises junction temperature to roughly 130 °C, which is acceptable. No external heatsink is required for any variant.
For 44-PLCC J-lead footprints, design the land pattern per IPC-7351 nominal density with 1.27 mm pitch rectangular pads of at least 0.65 mm width. Allow a 3 mm copper keep-out under the PLCC body for cleaning and inspection access. The PLCC socket (e.g., 44-pin machined-pin socket) is recommended for development boards to simplify MCU swap-out when migrating between commercial and industrial temperature grades.
Compliance Information
PIC16C74B family predates RoHS mandates; lead-free / halogen-free status not documented in retrieved sources. Not AEC-Q100 qualified - automotive designs should use the -04I or -04E variants and confirm compliance with Microchip environmental compliance documentation.
