PIC16LC66-04I/SP - 8-Bit 4MHz OTP MCU 14KB | Microchip
MPN: PIC16LC66-04I/SP β Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $5.68 | $5.68 |
| 10 | $5.11 | $51.10 |
| 100 | $4.54 | $454.00 |
| 500 | $4.09 | $2,045.00 |
| 1,000 | $3.65 | $3,650.00 |
PIC16LC66-04I/SP 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, MCUs belong to microcontrollers, which sit under embedded processors, which belong to integrated circuits. PIC microcontrollers are a popular mid-range family favored for their deterministic instruction set, low cost, and wide peripheral integration, and the PIC16C sub-family specifically uses OTP ROM for one-time field-programmable code storage. Designers select this category when deterministic real-time response, simplicity, and low per-unit cost outweigh the need for large memory or high clock speed.
Key features include three hardware timers: an 8-bit Timer0 with 8-bit prescaler, a 16-bit Timer1 with prescaler and external crystal/clock Sleep-mode increment capability, and an 8-bit Timer2. The device also integrates a 10-bit multi-channel ADC, a synchronous serial port (SSP) supporting SPI and I2C, a USART for asynchronous serial communication, and on-chip POR/BOR/watchdog protection. The βIβ suffix denotes the industrial temperature grade (-40C to +85C), and the βLCβ prefix indicates the low-power CMOS process variant optimized for reduced quiescent current consumption.
The PIC16LC66-04I/SP uses a Harvard architecture with separate program and data buses, allowing instruction fetch and operand access in a single clock cycle. Its OTP memory is programmed once and cannot be erased, making the part well suited to high-volume production where firmware is finalized. The instruction set is highly orthogonal, simplifying compiler output and reducing code density overhead versus accumulator-based CISC 8-bit cores.
Typical applications include industrial control subsystems, HVAC actuators, appliance control boards, sensor signal conditioning front-ends, motor control PWM stages, and low-cost embedded data loggers. The combination of OTP memory, the SSP, USART, and ADC makes the PIC16LC66-04I/SP a flexible platform for moderate-complexity, cost-sensitive designs where field firmware updates are not required.
When designing with this part, ensure that your programmer matches the 28-pin SPDIP package and supports the PIC16C OTP programming algorithm. Watchdog timer must be enabled in software if protection against code lockup is required. Decouple VDD with a 100nF ceramic capacitor placed within 5 mm of the supply pin, and reserve a 10 kohm pull-up on MCLR for proper reset behavior.
This page synthesizes distributor pricing, parametric comparison with PIC16C-family pin-compatible alternatives, and practical design notes not found in the manufacturer datasheet.
Drop-in alternatives for PIC16LC66-04I/SP 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 PIC16LC66-04I/SP (same form factor and footprint) β differing in Package, Program Memory Size, Mounting Type, Program Memory Type, RAM Size.
Quick Comparison Tool β Select alternative parts for side-by-side comparison:
PIC16LC66-04I/SO
β Drop-Inβ In Stock
$2.78 / Unit
View Datasheet βPIC16LC66-04/SP
β Drop-Inπ Reference alternative (not in catalog)
PIC16LC66-04I/P
β Drop-In β οΈ εζ°εΎ ιͺθ―π Reference alternative (not in catalog)
PIC16LC63-04I/SP
β Drop-Inβ In Stock
$1.85 / Unit
View Datasheet βPIC16LC65B-04I/P
β Drop-In β οΈ εζ°εΎ ιͺθ―π Reference alternative (not in catalog)
PIC16LC65B-04/PQ
β Drop-Inβ In Stock
$2.5 / Unit
View Datasheet βPIC16LC62A-04I/SO
β Drop-Inβ In Stock
$1.74 / Unit
View Datasheet βPIC16LC66-04I/SP Maximum Ratings & Electrical Characteristics
| Core Architecture | PIC 8-bit RISC (Harvard) |
| Series | PIC16C / PIC16LC66 |
| Program Memory Type | OTP (One-Time-Programmable) |
| Program Memory Size | 14 KB (8K x 14 words) |
| RAM | 368 bytes |
| Maximum Clock Speed | 4 MHz |
| Supply Voltage (VDD) | 2.5 V to 5.5 V |
| I/O Pins | 22 |
| Timers | 3 (Timer0 8-bit, Timer1 16-bit, Timer2 8-bit) |
| ADC | 8-channel, 8-bit (datasheet variant) |
| Serial Interfaces | SSP (SPI / I2C), USART |
| Operating Temperature | -40 C to +85 C (Industrial grade, 'I') |
| Package | 28-SPDIP (Skinny Plastic DIP, 7.62 mm / 0.300 in body width) |
| Mounting Type | Through-Hole (DIP) |
| RoHS Status | Compliant |
PIC16LC66-04I/SP Pin Configuration
| Pin 1 | MCLR/VPP β Master Clear (reset) input / programming voltage |
| Pin 2 | RA0/AN0 β PORTA bit 0 / analog input 0 |
| Pin 3 | RA1/AN1 β PORTA bit 1 / analog input 1 |
| Pin 4 | RA2/AN2 β PORTA bit 2 / analog input 2 |
| Pin 5 | RA3/AN3/VREF β PORTA bit 3 / analog input 3 / voltage reference |
| Pin 6 | RA4/T0CKI β PORTA bit 4 / Timer0 clock input |
| Pin 7 | RA5/AN4/SS β PORTA bit 5 / analog input 4 / SSP slave select |
| Pin 8 | OSC1/CLKIN β Oscillator input / external clock input |
| Pin 9 | OSC2/CLKOUT β Oscillator output / clock output |
| Pin 10 | RC0/T1OSO/T1CKI β PORTC bit 0 / Timer1 oscillator output / Timer1 clock input |
| Pin 11 | RC1/T1OSI/CCP2 β PORTC bit 1 / Timer1 oscillator input / CCP2 output |
| Pin 12 | RC2/CCP1 β PORTC bit 2 / CCP1 output (PWM/capture/compare) |
| Pin 13 | RC3/SCK/SCL β PORTC bit 3 / SSP serial clock (SPI/I2C) |
| Pin 14 | RC4/SDI/SDA β PORTC bit 4 / SSP serial data in (SPI) / I2C data |
| Pin 15 | RC5/SDO β PORTC bit 5 / SSP serial data out (SPI) |
| Pin 16 | RC6/TX/CK β PORTC bit 6 / USART transmit / USART clock |
| Pin 17 | RC7/RX/DT β PORTC bit 7 / USART receive / USART data |
| Pin 18 | GND β Ground reference |
| Pin 19 | VDD β Positive supply voltage (2.5V to 5.5V) |
| Pin 20 | RB0/INT β PORTB bit 0 / external interrupt input |
| Pin 21 | RB1 β PORTB bit 1 |
| Pin 22 | RB2 β PORTB bit 2 |
| Pin 23 | RB3 β PORTB bit 3 |
| Pin 24 | RB4 β PORTB bit 4 |
| Pin 25 | RB5 β PORTB bit 5 |
| Pin 26 | RB6/PGC β PORTB bit 6 / ICSP clock input |
| Pin 27 | RB7/PGD β PORTB bit 7 / ICSP data input/output |
| Pin 28 | NC β Not connected (per datasheet) |
Typical Applications
PIC16LC66-04I/SP is suitable for 6 applications: Industrial Control Subsystems, HVAC Actuator Controllers, Appliance Control Boards, Sensor Signal Conditioning Front-Ends, Low-Cost Data Logging Devices, Motor Drive PWM Stages.
Industrial Control Subsystems
The PIC16LC66-04I/SP is a strong fit for industrial control subsystems because its 14 KB OTP memory, 22 I/O lines, and 2.5-5.5 V supply range match the voltage and pin-count requirements of 24 V-tolerant logic interfaces (via external transzorbs or optocouplers). Its three hardware timers allow precise PWM generation for motor speed control and process-variable sampling at deterministic intervals. The industrial temperature grade (-40C to +85C) ensures operation on factory floors without thermal derating, and the LC process variant reduces quiescent current in always-on control cabinets, lowering thermal dissipation versus the standard PIC16C66.
Recommended
HVAC Actuator Controllers
In HVAC damper and valve actuator controllers, the PIC16LC66-04I/SP's SSP (SPI/I2C) interface allows direct connection to digital temperature sensors and EEPROM non-volatile memory without glue logic, while the USART supports Modbus RTU communication to the central building automation controller. Its 4 MHz clock provides adequate throughput for proportional-integral control loops with 10 ms update rates. The OTP memory reduces per-unit cost in high-volume HVAC equipment where firmware is finalized at release, and the DIP package simplifies field service and rework on installed units.
Recommended
Appliance Control Boards
The PIC16LC66-04I/SP is widely deployed in white-goods appliance control boards (washing machines, dishwashers, microwave ovens) where its 22 I/O lines directly drive relay coils, triac gates, and seven-segment LED displays without external drivers. The 14 KB OTP memory accommodates multi-state wash-cycle or cook-profile firmware, while the 368-byte RAM supports buffered user-input debouncing. Industrial-grade temperature rating and the LC low-power process variant ensure reliable cold-start operation in unheated laundry rooms and stable long-term operation in oven-mounted control panels.
Recommended
Sensor Signal Conditioning Front-Ends
For sensor signal conditioning front-ends, the PIC16LC66-04I/SP's integrated 8-channel ADC (datasheet variant) samples analog inputs directly from thermistor bridges, load cells, and pressure transducers without external multiplexer ICs. The 14 KB OTP memory stores calibration lookup tables and linearization coefficients for non-linear sensors, while the USART streams conditioned readings to a host controller at 9600 to 115200 baud. The 2.5-5.5 V range allows direct power from a 3.3 V regulated sensor rail, and the low quiescent current of the LC process minimizes self-heating that would otherwise bias the analog readings.
Recommended
Low-Cost Data Logging Devices
In low-cost data logging devices (temperature/humidity loggers, energy meters, fleet trackers), the PIC16LC66-04I/SP combines a 14 KB OTP firmware image with 368 bytes of RAM to buffer sensor readings before batch transmission via USART. The PIC16LC66-04I/SP's SSP port connects to external serial EEPROM or FRAM for non-volatile log storage without SPI bus contention, and the 4 MHz clock is sufficient for periodic sampling at 1 Hz to 100 Hz while maintaining low active-duty current. The OTP nature prevents accidental firmware tampering in field-deployed loggers and reduces production programming cost.
Recommended
Motor Drive PWM Stages
For DC and stepper motor PWM drive stages in low-voltage motion control, the PIC16LC66-04I/SP generates complementary PWM signals on Timer2 with up to 10-bit resolution at 4 MHz, allowing software-tuned acceleration and deceleration ramps. The 22 I/O pins directly drive H-bridge gate drivers (such as the IR2104) and accept Hall-effect sensor feedback for commutation. The industrial temperature rating supports under-hood automotive auxiliary motor applications, and the DIP package simplifies development-bench prototyping before transitioning to the SOIC variant for SMT production.
Recommended
Recommended Products Summary
Engineering reference data for PIC16LC66-04I/SP β comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16LC66-04I/SO | PIC16LC66-04/SP | PIC16LC63-04I/SP |
|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 28-SPDIP (0.300 in, 7.62 mm) | 28-SOIC (same footprint family, SMT) | 28-SPDIP (same) | 28-SPDIP (same) |
| Program Memory | 14 KB (8K x 14) OTP | 14 KB OTP | 14 KB OTP | 7 KB OTP (-50%) |
| RAM | 368 bytes | 368 bytes | 368 bytes | 192 bytes (-48%) |
| Clock Speed | 4 MHz | 4 MHz | 4 MHz | 4 MHz |
| Supply Voltage | 2.5 V to 5.5 V | 2.5 V to 5.5 V | 2.5 V to 5.5 V | 2.5 V to 5.5 V |
| I/O Pins | 22 | 22 | 22 | 22 |
| Temperature Grade | Industrial (-40C to +85C) | Industrial (-40C to +85C) | Commercial (0C to +70C) | Industrial (-40C to +85C) |
Key Differentiators
- Low-power 'LC' process variant (vs Standard PIC16C66 (non-LC))
- Industrial temperature grade in SPDIP package (vs PIC16C711-04/P (commercial grade, 20-pin DIP))
- Integrated USART peripheral (vs PIC16C711-04/P)
Design Notes
Place a 100 nF ceramic decoupling capacitor within 5 mm of the VDD pin (pin 19) and a bulk 10 uF tantalum or aluminum electrolytic capacitor on the same supply rail. The PIC16LC66-04I/SP's LC process variant draws approximately 2 mA active current at 5 V and 4 MHz; for Sleep-mode designs add a 10 kohm pull-up on MCLR (pin 1) to prevent spurious resets during brown-out events.
The PIC16LC66-04I/SP uses OTP (One-Time-Programmable) memory - verify the firmware image is final before programming, as OTP cells cannot be electrically erased or rewritten. A common pitfall is attempting to use a Flash-based PIC programmer profile; the OTP algorithm requires VPP of 13.0 V on MCLR during programming per the DS30261D programming specification. Confirm your programmer supports the PIC16C6X OTP algorithm.
For 28-SPDIP through-hole layouts, use a 0.100 in (2.54 mm) row pitch with 0.6 mm drill holes and 1.5 mm pads. Route the oscillator traces (OSC1/OSC2, pins 8-9) short and symmetric, with the crystal or resonator placed within 10 mm of the IC to minimize stray capacitance. If using an external clock source, drive OSC1 only and leave OSC2 floating per datasheet guidance.
Compliance Information
RoHS and REACH compliant per Microchip product declarations. AEC-Q100 qualification status not documented on the public product page - contact Microchip factory for automotive-grade assessment. Lead-free (Pb-free) terminal finish confirmed per Microchip material declaration.
