PIC16C74A-04/L - 8-Bit 4MHz OTP MCU 7KB 33 I/O PLCC-44 | Microchip
MPN: PIC16C74A-04/L ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $9.95 | $9.95 |
| 10 | $8.96 | $89.60 |
| 100 | $7.85 | $785.00 |
| 500 | $6.95 | $3,475.00 |
| 1,000 | $6.1 | $6,100.00 |
PIC16C74A-04/L Overview
A microcontroller (MCU) is a single-chip computer integrating a CPU, memory (RAM/ROM/Flash), and peripherals on one die; an 8-bit MCU processes data in 8-bit chunks and is the workhorse of embedded control where cost, determinism, and low power outweigh raw computational throughput. The PIC16C7X family uses a RISC architecture with 35 single-word instructions, where all instructions execute in one cycle except program branches (two cycles). The PIC16C74A-04/L variant is the 4 MHz speed grade (the -04 suffix) in a windowed/leadless PLCC package (the /L suffix), making it suitable for development and lab work as well as production designs.
Key differentiating features include high sink/source current of 25 mA/25 mA per I/O (sufficient to drive LEDs and small relays directly), integrated 8-channel 8-bit ADC for analog sensor input, low-power operation down to 1 µA typical standby at 3 V/32 kHz, and an integrated Watchdog Timer with its own on-chip RC oscillator for reliable reset behavior. The wide operating voltage range (2.5 V to 6.0 V), high-performance RISC CPU, and OTP program memory make the part well-suited to volume production where firmware is finalized and code protection is required.
Architecture-wise, the PIC16C74A uses a Harvard bus structure with separate program and data paths, a 14-bit instruction word, and a 8-bit data path. The 4 MHz clock speed grade provides 1 µs instruction cycle time, enabling precise timing loops without resorting to software overhead. The 192-byte RAM is shared between general-purpose registers and Special Function Registers (SFRs), with banked memory access for the larger register file.
Typical applications include industrial control systems, sensor signal conditioning with on-chip ADC, motor control via PWM outputs, appliance control (white goods), automotive body electronics (non-safety), and embedded data acquisition systems. The OTP program memory is appropriate for high-volume production with stable firmware; for field-updatable designs, the flash-based PIC16F74 is recommended as a direct functional successor.
When designing with this part, note that OTP memory cannot be erased - prototypes should use the JW (windowed CERDIP) variant for UV erasure. A 3.0 V to 6.0 V supply range allows operation directly from a 5 V regulated rail or four-cell battery stack. Ensure MCLR reset circuit includes the proper pull-up and any in-circuit Serial Programming (ICSP) isolation is correctly handled.
This page synthesizes distributor pricing, drop-in same-package alternatives, and practical design notes not found in the standalone manufacturer datasheet, enabling faster sourcing decisions for engineers maintaining or replacing PIC16C74A-04/L designs.
Drop-in alternatives for PIC16C74A-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 PIC16C74A-04/L (same form factor and footprint) — differing in Mounting Type, Package, Data EEPROM, Instruction Cycle Time, Operating Temperature Range.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC16C74A-04I/L
✅ Drop-In📋 Reference alternative (not in catalog)
PIC16C74A-10/L
✅ Drop-In✓ In Stock
$8.4 / Unit
View Datasheet →PIC16C74A-20/L
✅ Drop-In✓ In Stock
$7.1 / Unit
View Datasheet →PIC16C74B-04/L
✅ Drop-In✓ In Stock
$3.32 / Unit
View Datasheet →PIC16C74AT-04/L
✅ Drop-In📋 Reference alternative (not in catalog)
PIC16F74-I/L
✅ Drop-In📋 Reference alternative (not in catalog)
PIC16C74A-04/L Maximum Ratings & Electrical Characteristics
| Manufacturer | Microchip Technology |
| Series | PIC16C7X (mid-range 8-bit) |
| Core Processor | PIC |
| Core Size | 8-bit |
| Max CPU Speed | 4 MHz |
| Instruction Cycle Time | 1 µs at 4 MHz |
| Program Memory Type | OTP (One-Time Programmable) |
| Program Memory Size | 7 KB (4K x 14 words) |
| RAM Size | 192 bytes |
| I/O Pins | 33 |
| ADC Channels | 8 channels x 8-bit |
| Supply Voltage (Vcc) | 4.0 V to 5.5 V (operating) |
| Wide Operating Voltage Range | 2.5 V to 6.0 V |
| I/O Sink/Source Current | 25 mA / 25 mA per pin |
| Package | 44-pin PLCC (16.59 x 16.59 mm) |
| Mounting Type | Surface Mount (PLCC socket optional) |
| Operating Temperature | -40 °C to +85 °C (industrial) |
| Standby Current (typ) | 1 µA at 3 V, 32 kHz |
| Active Current (typ) | 15 µA at 5 V, 4 MHz (low-power mode) |
| Instruction Set | 35 single-word instructions |
| Data EEPROM | Not present (OTP device) |
| Watchdog Timer | Yes (with dedicated on-chip RC oscillator) |
| Peripherals | Brown-out Detect, PWM, Capture/Compare, Timer, USART |
PIC16C74A-04/L Pin Configuration
| Pin 1 | MCLR — Master Clear (Reset) input, with internal pull-up |
| Pin 2 | RA0/AN0 — Digital I/O port A bit 0 / ADC analog input 0 |
| Pin 3 | RA1/AN1 — Digital I/O port A bit 1 / ADC analog input 1 |
| Pin 4 | RA2/AN2 — Digital I/O port A bit 2 / ADC analog input 2 |
| Pin 5 | RA3/AN3/VREF+ — Digital I/O port A bit 3 / ADC analog input 3 / ADC positive reference |
| Pin 6 | RA4/T0CKI — Digital I/O port A bit 4 / Timer 0 clock input (open-drain) |
| Pin 7 | RA5/AN4/SS — Digital I/O port A bit 5 / ADC analog input 4 / SPI slave select |
| Pin 8 | RE0/RD/AN5 — Digital I/O port E bit 0 / Parallel port read / ADC input 5 |
| Pin 9 | RE1/WR/AN6 — Digital I/O port E bit 1 / Parallel port write / ADC input 6 |
| Pin 10 | RE2/CS/AN7 — Digital I/O port E bit 2 / Parallel port chip select / ADC input 7 |
| Pin 11 | Vcc — Positive logic supply voltage |
| Pin 12 | Vss — Logic ground reference |
| Pin 13 | OSC1/CLKIN — Oscillator crystal input / external clock input |
| Pin 14 | OSC2/CLKOUT — Oscillator crystal output / clock output (4 x fosc) |
| Pin 15 | RC0/T1OSO/T1CKI — Digital I/O port C bit 0 / Timer 1 oscillator output / Timer 1 clock input |
| Pin 16 | RC1/T1OSI/CCP2 — Digital I/O port C bit 1 / Timer 1 oscillator input / CCP2 module |
| Pin 17 | RC2/CCP1 — Digital I/O port C bit 2 / CCP1 PWM module |
| Pin 18 | RC3/SCK/SCL — Digital I/O port C bit 3 / SPI clock / I2C clock |
| Pin 19 | RD0/PSP0 — Digital I/O port D bit 0 / Parallel Slave Port bit 0 |
| Pin 20 | RD1/PSP1 — Digital I/O port D bit 1 / Parallel Slave Port bit 1 |
| Pin 21 | RD2/PSP2 — Digital I/O port D bit 2 / Parallel Slave Port bit 2 |
| Pin 22 | RD3/PSP3 — Digital I/O port D bit 3 / Parallel Slave Port bit 3 |
| Pin 23 | RC4/SDI/SDA — Digital I/O port C bit 4 / SPI data in / I2C data |
| Pin 24 | RC5/SDO — Digital I/O port C bit 5 / SPI data out |
| Pin 25 | RC6/TX/CK — Digital I/O port C bit 6 / USART async transmit / USART sync clock |
| Pin 26 | RC7/RX/DT — Digital I/O port C bit 7 / USART async receive / USART sync data |
| Pin 27 | RD4/PSP4 — Digital I/O port D bit 4 / Parallel Slave Port bit 4 |
| Pin 28 | RD5/PSP5 — Digital I/O port D bit 5 / Parallel Slave Port bit 5 |
| Pin 29 | RD6/PSP6 — Digital I/O port D bit 6 / Parallel Slave Port bit 6 |
| Pin 30 | RD7/PSP7 — Digital I/O port D bit 7 / Parallel Slave Port bit 7 |
| Pin 31 | Vss — Logic ground reference |
| Pin 32 | Vcc — Positive logic supply voltage |
| Pin 33 | RB0/INT — Digital I/O port B bit 0 / External interrupt input |
| Pin 34 | RB1 — Digital I/O port B bit 1 |
| Pin 35 | RB2 — Digital I/O port B bit 2 |
| Pin 36 | RB3/PGM — Digital I/O port B bit 3 / Low-voltage ICSP programming input |
| Pin 37 | RB4 — Digital I/O port B bit 4 (interrupt-on-change) |
| Pin 38 | RB5 — Digital I/O port B bit 5 (interrupt-on-change) |
| Pin 39 | RB6/PGC — Digital I/O port B bit 6 / ICSP serial clock |
| Pin 40 | RB7/PGD — Digital I/O port B bit 7 / ICSP serial data |
| Pin 41 | NC — Not connected (PLCC pin reserved, no internal bond) |
| Pin 42 | NC — Not connected (PLCC pin reserved, no internal bond) |
| Pin 43 | NC — Not connected (PLCC pin reserved, no internal bond) |
| Pin 44 | NC — Not connected (PLCC pin reserved, no internal bond) |
Typical Applications
PIC16C74A-04/L is suitable for 7 applications: Industrial Process Control PLC, Appliance Control Board (White Goods), Automotive Body Electronics, Sensor Data Acquisition Module, Motor Control PWM Drive, Embedded HMI Keypad / LCD Interface, Battery-Powered Remote Sensor Node.
Industrial Process Control PLC
The PIC16C74A-04/L fits industrial process control where its 8-channel 8-bit ADC reads 4-20 mA loop sensors via shunt resistors, and 33 I/O pins drive indicator LEDs, relays, and keypads. With 7 KB OTP program memory it holds PID control loops, alarm state machines, and HMI scan routines for small PLCs. The wide -40 to +85 C industrial temperature range and 25 mA sink/source per pin eliminate external driver transistors for solenoid and relay coils. Per Microchip application notes, the integrated Brown-out Reset prevents corrupted writes to non-volatile setpoints during supply dips common in 24 V industrial bus systems. The PIC16C74A-04/L is paired with the MCP6002 op-amp for sensor conditioning and the MCP1700 LDO for 5 V rail regulation in a typical node.
Recommended
Appliance Control Board (White Goods)
The PIC16C74A-04/L suits washing machine, dishwasher, and oven control boards where its OTP memory locks the final firmware for regulatory certification, 25 mA I/O directly drives triac optocouplers and LED indicators, and the integrated PWM modules control motor speed. The 8 ADC channels read temperature sensors (NTC thermistors), water level, and door-latch status. Per the Microchip datasheet, the low standby current of 1 µA at 3 V enables long battery life in cordless appliances. OTP memory prevents unauthorized firmware modifications that could violate UL/CE safety certifications on consumer white goods. Pair the PIC16C74A-04/L with MOC3021 triac drivers and a ULN2003 relay driver array for typical 120/240 VAC load switching.
Recommended
Automotive Body Electronics
The PIC16C74A-04/L handles non-safety automotive body modules such as seat-position memory, mirror adjust, interior lighting, and accessory timers where its 33 I/O drive small motors and lamps, the 8 ADC reads potentiometer position feedback, and OTP memory locks the calibration data. Operating voltage tolerance to 6.0 V covers load-dump transients after external TVS clamping per the Microchip datasheet. The PIC16C74A-04/L is NOT AEC-Q100 qualified - for new automotive designs use AEC-Q100-qualified PIC16F74 variants. Pair with the MCP2551 CAN transceiver for body-network nodes or with discrete MOSFET drivers for seat motors.
Recommended
Sensor Data Acquisition Module
The PIC16C74A-04/L functions as a stand-alone data logger front-end where its 8-channel 8-bit ADC multiplexes thermocouple/pressure/flow sensor inputs, USART streams digitized readings to a host PC or display, and 192 bytes of RAM buffer average samples before transmission. The 4 MHz instruction rate delivers ~25 µs per ADC conversion cycle, sufficient for thermal monitoring at 10 Hz per channel. Per the Microchip datasheet, the integrated Watchdog Timer with dedicated RC oscillator ensures the module auto-recovers from ESD-induced firmware lockups in field-deployed sensor installations.
Recommended
Motor Control PWM Drive
The PIC16C74A-04/L generates complementary PWM outputs to drive a three-phase brushless DC (BLDC) or stepper motor via external gate drivers, using the integrated Capture/Compare/PWM (CCP) modules at up to 10-bit resolution. The 33 I/O accommodate Hall-sensor feedback inputs, direction/ brake logic, and fault monitoring. Per Microchip application note AN857, the 25 mA I/O source can directly drive small logic-level MOSFET gates in low-power fans and pumps. The 192-byte RAM accommodates the commutation state table and current-loop PI controller variables. Pair the PIC16C74A-04/L with the IR2104 gate driver for half-bridge or with the L6234 three-phase driver IC.
Recommended
Embedded HMI Keypad / LCD Interface
The PIC16C74A-04/L interfaces with 4x4 matrix keypads and character LCDs (HD44780-compatible 16x2 or 20x4 displays) via its 33 I/O, with timer-driven keypad scan routines and busy-flag polled LCD writes. OTP memory locks the menu navigation state machine and character-set customizations for OEM branding. Per the Microchip datasheet, the integrated 8-bit ADC can read an analog joystick or rotary encoder potentiometer alongside digital inputs. Pair with the PCF8574 I/O expander if more keys are needed beyond the 33 native I/O, and use the MCP23008 for I2C-based keypad scanning.
Recommended
Battery-Powered Remote Sensor Node
The PIC16C74A-04/L operates in battery-powered remote sensor applications where its 1 µA typical standby current at 3 V enables multi-year life from two AA cells, and the wide 2.5 V to 6.0 V operating range accommodates battery droop. The 4 MHz active CPU reads sensor data, transmits via USART-connected radio module, and returns to sleep under Watchdog Timer control. Per the Microchip datasheet, the integrated Brown-out Reset prevents data corruption at end-of-life battery voltage. Pair with the MRF24J40 2.4 GHz radio or the XBee module for wireless sensor networks, and use the MCP1700 LDO for 3.3 V regulated rail.
Recommended
Recommended Products Summary
Engineering reference data for PIC16C74A-04/L — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16C74A-04I/L | PIC16C74A-10/L | PIC16C74B-04/L | PIC16F74-I/L |
|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 44-pin PLCC (16.59x16.59 mm) | 44-PLCC - same | 44-PLCC - same | 44-PLCC - same | 44-PLCC - same |
| Program Memory | 7 KB OTP (4K x 14) | 7 KB OTP | 7 KB OTP | 7 KB OTP | 7 KB Flash |
| Max CPU Speed | 4 MHz | 4 MHz | 10 MHz | 4 MHz | 20 MHz |
| Memory Type | OTP (one-time) | OTP | OTP | OTP | Flash (reprogrammable) |
| Temperature Grade | Commercial (0 to +70 C) | Industrial (-40 to +85 C) | Commercial | Commercial | Industrial |
| ADC Channels | 8 x 8-bit | 8 x 8-bit | 8 x 8-bit | 8 x 8-bit | 8 x 8-bit |
| I/O Pins | 33 | 33 | 33 | 33 | 33 |
| Recommended Replacement | Legacy - use PIC16F74 | Legacy - use PIC16F74-I/L | Legacy - use PIC16F74-I/L | Legacy - use PIC16F74-I/L | Active flash-based successor |
Key Differentiators
- Highest-current 8-bit MCU in 44-PLCC class with 25 mA I/O (vs PIC16F74-I/L)
- OTP code protection for certified regulatory designs (vs PIC16F74-I/L)
- Wide 2.5 V to 6.0 V operating range with integrated brown-out (vs PIC16F874-04/L)
Design Notes
Decouple Vcc to Vss with both a 100 nF ceramic capacitor placed within 5 mm of pins 11/12 (and 31/32) and a bulk 10 µF tantalum or aluminum electrolytic. Per Microchip datasheet DS30323E, the 44-PLCC has two Vcc/Vss pairs (pins 11/12 and 31/32) and BOTH must be connected to minimize supply inductance during transient ADC switching. Brown-out Reset (BOR) should be enabled in the configuration word to hold the part in reset when Vcc falls below 4.0 V, preventing corrupted OTP writes. Use a low-ESR LDO such as MCP1700 or LM7805 to keep ripple below 50 mV for reliable ADC operation.
Place a 4-pin ICSP header (Vpp/MCLR, PGD/RB7, PGC/RB6, Vss) even on production boards for in-circuit programming and field firmware updates. Keep the MCLR pull-up resistor (typically 10 kΩ to Vcc) close to the pin. For the 4 MHz crystal/resonator on OSC1/OSC2 (pins 13/14), use a crystal with 20 pF load capacitors tied to Vss; route crystal traces short and guard with a ground ring to reduce EMI. Per the Microchip datasheet, the RB6/RB7 ICSP pins have Schmitt-trigger inputs and can be left as user I/O after programming by setting the appropriate configuration bit.
Do not exceed 6.0 V on Vcc or apply voltage to any pin before Vcc is established - the PIC16C74A-04/L lacks the 5 V-tolerant I/O of newer PIC18 devices and latch-up can occur. When using ADC inputs (RA0-RA5, RE0-RE2), configure the corresponding TRIS bit as input and disable the digital input buffer via the ADCON1 register to prevent digital switching from coupling into the analog measurement. Do not omit the 100 nF bypass on Vref+ (RA3) when used as ADC reference - reference noise directly degrades ADC accuracy. OTP memory cannot be erased, so prototypes should use the PIC16C74A-04/JW windowed CERDIP variant for UV erasure during development.
The 25 mA I/O sink/source capability allows direct drive of LEDs with appropriate series resistors (e.g., 220 Ω for 5 V logic with 2.0 V LED drop), but high-current switching creates ground bounce on shared Vss pins. For mixed-signal designs, use separate analog and digital ground planes joined at a single point near the MCU Vss pins. The 8-bit ADC achieves ~9.5 effective bits when the input source impedance is below 2 kΩ - use an op-amp buffer (MCP6002) when reading high-impedance sensors. Keep ADC traces short and away from PWM outputs to minimize digital-to-analog crosstalk.
Compliance Information
RoHS, REACH, lead-free, and halogen-free status are not specified in the verified distributor data for the PLCC variant; PIC16C74A series predates widespread RoHS transition. NOT AEC-Q100 qualified - do not use in automotive safety-critical designs without additional qualification. For new automotive designs, use AEC-Q100-qualified PIC16F74 variants. Conflict-mineral compliance status is not stated in verified data.
