PIC16C66-10E/SO - 8-Bit 10MHz MCU 14KB OTP 28-SOIC | Microchip
MPN: PIC16C66-10E/SO ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $7.1 | $7.10 |
| 10 | $6.4 | $64.00 |
| 100 | $5.55 | $555.00 |
| 500 | $4.95 | $2,475.00 |
| 1,000 | $4.4 | $4,400.00 |
PIC16C66-10E/SO Overview
What is a PIC16C66? The PIC16C66 belongs to the PIC16C6X family of mid-range, low-cost, high-performance CMOS, fully-static 8-bit microcontrollers built on Microchip's RISC architecture. PIC MCUs sit within the broader microcontroller (MCU) hierarchy: microcontroller -> embedded processor -> semiconductor IC. These devices execute 35 single-word instructions, with all instructions completing in a single cycle except program branches, which take two cycles. The PIC16C6X family was one of Microchip's mainstream mid-range architectures before being superseded by the flash-based PIC16F6X line.
Key features of the PIC16C66-10E/SO include 22 I/O pins supporting digital and analog peripheral functions, 3 timer modules, a synchronous/asynchronous serial port (SSP/USART), a 5-channel 8-bit ADC, and 8K x 14 (14KB) OTP program memory. The wide 4V-5.5V supply range and 10MHz operation deliver instruction-cycle throughput suitable for real-time control loops. The 28-SOIC package balances board area and breadboard-friendly pitch while remaining suitable for automated SMT assembly.
Architecturally, the PIC16C66-10E/SO uses a Harvard-style RISC core with separate program and data buses, allowing instruction fetch and operand access to occur in parallel. The OTP program memory is one-time programmable (not re-programmable in-circuit), which is appropriate for volume production where firmware is stable. The "E" suffix designates the extended temperature grade of -40°C to +125°C, suiting the device for harsh automotive and industrial enclosures.
Typical applications include automotive body and chassis subsystems, industrial control panels, appliance motor control, sensor signal conditioning, low-end UART-based communication bridges, and white-goods user-interface controllers. The extended temperature range also suits outdoor signage and HVAC control.
A key design consideration with OTP microcontrollers is that firmware cannot be field-updated. Designers should plan for in-circuit emulation or a flash-based sibling (e.g., PIC16F66) during prototyping, and verify that programming voltage (typically 13V on the Vpp pin) is correctly applied during production programming. For new designs, Microchip generally recommends migrating to the flash-based PIC16F family for code-revision flexibility.
This page synthesizes verified distributor pricing, drop-in compatible alternatives, and practical engineering notes not found on a single manufacturer datasheet, giving procurement and design engineers a one-stop reference.
Drop-in alternatives for PIC16C66-10E/SO — 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 PIC16C66-10E/SO (same form factor and footprint) — differing in Package, Timers, ADC, Core Architecture, Program Memory Type.
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No drop-in alternatives available for this product.
Request AlternativesPIC16C66-10E/SO Maximum Ratings & Electrical Characteristics
| Core Architecture | PIC 8-bit RISC |
| Family | PIC® 16C |
| Sub-family | PIC16C6X |
| Program Memory Type | OTP (One-Time Programmable) |
| Program Memory Size | 14KB (8K x 14) |
| RAM | 368 bytes |
| Maximum Clock Frequency | 10 MHz |
| Supply Voltage (Vdd) | 4.0 V to 5.5 V |
| I/O Pins | 22 |
| ADC | 8-bit, 5 channels |
| Timers | 3 modules |
| Serial Interface | SSP / USART |
| Operating Temperature Grade | Extended (-40°C to +125°C, "E") |
| Package | 28-SOIC (7.50 mm body width) |
| Mounting Type | Surface Mount |
| Terminal Form | Gull Wing |
PIC16C66-10E/SO Pin Configuration
| Pin 1 | RA2/AN2/VREF- — PORTA bit 2 / ADC input 2 / ADC negative reference |
| Pin 2 | RA3/AN3/VREF+ — PORTA bit 3 / ADC input 3 / ADC positive reference |
| Pin 3 | RA4/T0CKI — PORTA bit 4 / Timer0 clock input |
| Pin 4 | RA5/AN4/SS — PORTA bit 5 / ADC input 4 / SPI slave select |
| Pin 5 | Vss — Ground reference |
| Pin 6 | RB0/INT — PORTB bit 0 / external interrupt |
| Pin 7 | RB1 — PORTB bit 1 |
| Pin 8 | RB2 — PORTB bit 2 |
| Pin 9 | RB3 — PORTB bit 3 |
| Pin 10 | RB4 — PORTB bit 4 |
| Pin 11 | RB5 — PORTB bit 5 |
| Pin 12 | RB6/PGC — PORTB bit 6 / ICSP clock |
| Pin 13 | RB7/PGD — PORTB bit 7 / ICSP data |
| Pin 14 | Vss — Ground reference |
| Pin 15 | OSC1/CLKIN — Oscillator input / external clock |
| Pin 16 | OSC2/CLKOUT — Oscillator output / clock out |
| Pin 17 | RC0/T1OSO/T1CKI — PORTC bit 0 / Timer1 oscillator output / Timer1 clock |
| Pin 18 | RC1/T1OSI/CCP2 — PORTC bit 1 / Timer1 oscillator input / CCP2 |
| Pin 19 | RC2/CCP1 — PORTC bit 2 / CCP1 PWM/capture |
| Pin 20 | RC3/SCK/SCL — PORTC bit 3 / SPI clock / I2C clock |
| Pin 21 | RC4/SDI/SDA — PORTC bit 4 / SPI data in / I2C data |
| Pin 22 | RC5/SDO — PORTC bit 5 / SPI data out |
| Pin 23 | RC6/TX/CK — PORTC bit 6 / USART TX / USART clock |
| Pin 24 | RC7/RX/DT — PORTC bit 7 / USART RX / USART data |
| Pin 25 | Vss — Ground reference |
| Pin 26 | VDD — Positive supply |
| Pin 27 | RA0/AN0 — PORTA bit 0 / ADC input 0 |
| Pin 28 | RA1/AN1 — PORTA bit 1 / ADC input 1 |
Typical Applications
PIC16C66-10E/SO is suitable for 6 applications: Automotive Body Electronics, Industrial Control Panels, Appliance Motor Control, Sensor Signal Conditioning, UART Communication Bridges, HVAC and Outdoor Signage.
Automotive Body Electronics
The PIC16C66-10E/SO is well suited for under-hood and body-electronics modules thanks to its extended -40C to +125C operating temperature grade (verified by the "E" suffix). At 10 MHz clock it delivers ~5 MIPS throughput, enough for body controllers, mirror-adjustment logic, lighting multiplexers, and simple sensor read loops. The 22 I/O lines support multiple switch inputs, relay drives, and PWM channels for LED dimming or motor control. The OTP memory suits high-volume automotive programs where firmware is locked at production. Engineers designing CAN/LIN nodes typically pair this MCU with a stand-alone CAN controller; the on-chip USART can drive LIN master/slave stacks at 10.4 kbaud.
Recommended
Industrial Control Panels
In industrial HMI panels and process-control boards, the PIC16C66-10E/SO's 8-bit RISC core, 22 I/O, and 5-channel 8-bit ADC enable direct interface to pushbuttons, rotary encoders, and 0-5V analog sensors. The 4V-5.5V supply range accommodates 5V industrial rails; the extended temperature grade allows placement inside enclosures near heating elements or in unconditioned factory floors. At 10 MHz, instruction cycles execute in 100-200 ns, so PID loops with millisecond update rates fit comfortably. The OTP memory ensures firmware integrity against accidental erasure in the field, while the 28-SOIC package keeps the footprint manageable inside DIN-rail enclosures.
Recommended
Appliance Motor Control
White-goods appliances such as washing machines, dishwashers, and refrigerators use 8-bit MCUs like the PIC16C66-10E/SO to drive TRIAC-commutated AC motors, read water-level sensors, and coordinate user-interface keypads. The 22 I/O pins multiplex triac firing pulses, zero-cross detection, pump relay drives, and buzzer outputs without external glue logic. The on-chip 8-bit ADC monitors thermistor inputs and motor current shunts. The PIC16C6X instruction set simplifies bit-banging protocols for legacy appliance buses. Designers choose the OTP variant over flash for cost-sensitive high-volume production where firmware revisions are infrequent.
Recommended
Sensor Signal Conditioning
The PIC16C66-10E/SO's 5-channel 8-bit ADC, 22 I/O, and USART make it a practical front-end for multi-sensor data acquisition nodes. It can digitize thermocouple-amplified signals, photodiode currents via transimpedance amplifiers, and 4-20 mA loop-derived voltages while averaging out 50/60 Hz line noise through software filtering. Acquired readings can be streamed over RS-232/RS-485 using the USART, or buffered in the 368-byte RAM and burst-uploaded. The extended temperature grade supports outdoor installation in weather stations and HVAC duct sensors where ambient swings exceed 100 K.
Recommended
UART Communication Bridges
With its built-in USART, the PIC16C66-10E/SO excels as a low-cost protocol converter between legacy UART peripherals and modern buses. Common bridge applications include UART-to-I2C, UART-to-SPI, or UART-to-parallel-IO translation. The 10 MHz clock gives instruction cycles short enough to bit-bang I2C at 100/400 kHz while servicing the USART interrupt. The OTP memory ensures field-deployed firmware cannot be corrupted by supply transients. Compared with discrete UART bridges, this MCU provides flexible, programmable protocol mapping for custom industrial buses or proprietary telemetry stacks.
Recommended
HVAC and Outdoor Signage
HVAC control boards, outdoor LED signage drivers, and parking-lot equipment benefit from the PIC16C66-10E/SO's extended temperature grade and 5V operation. The MCU can sequence compressor contactors, monitor return-air temperatures, drive character LCDs, and implement simple scheduling. For LED signage, its 22 I/O channels multiplex row/column scanning of small dot-matrix displays; 10 MHz throughput keeps refresh rates flicker-free. The OTP memory locks in regulatory-certified firmware, a common requirement in HVAC safety standards (UL 1995, IEC 60335).
Recommended
Recommended Products Summary
Engineering reference data for PIC16C66-10E/SO — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16C66-10I/SO | PIC16C66-10/SO | PIC16C66T-10E/SO | PIC16C66T-10/SO | PIC16C66-04E/SO |
|---|---|---|---|---|---|---|
| Package | 28-SOIC (7.50 mm) | 28-SOIC - same | 28-SOIC - same | 28-SOIC - same | 28-SOIC - same | 28-SOIC - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Max Clock Frequency | 10 MHz | 10 MHz | 10 MHz | 10 MHz | 10 MHz | 4 MHz |
| Temperature Grade | Extended (-40C to +125C) | Industrial (-40C to +85C) | Commercial (0C to +70C) | Extended (-40C to +125C) | Commercial (0C to +70C) | Extended (-40C to +125C) |
| Program Memory | 14 KB OTP | 14 KB OTP | 14 KB OTP | 14 KB OTP | 14 KB OTP | 14 KB OTP |
| RAM | 368 bytes | 368 bytes | 368 bytes | 368 bytes | 368 bytes | 368 bytes |
| I/O Pins | 22 | 22 | 22 | 22 | 22 | 22 |
| ADC | 8-bit, 5 ch | 8-bit, 5 ch | 8-bit, 5 ch | 8-bit, 5 ch | 8-bit, 5 ch | 8-bit, 5 ch |
| Supply Voltage | 4.0 V to 5.5 V | 4.0 V to 5.5 V | 4.0 V to 5.5 V | 4.0 V to 5.5 V | 4.0 V to 5.5 V | 4.0 V to 5.5 V |
| Approx Unit Price (qty 1) | USD 7.10 | USD ~6.50 | USD ~6.00 | USD ~7.10 | USD ~6.00 | USD ~6.50 |
Key Differentiators
- Extended operating temperature grade for automotive/industrial (vs PIC16C66-10/SO)
- Higher instruction throughput than slower sibling (vs PIC16C66-04E/SO)
- Industry-standard 28-SOIC footprint with 22 I/O pins (vs PIC16F66-I/SO (flash-based equivalent))
Design Notes
The OTP program memory cannot be erased. Always verify firmware on a flash-based sibling (PIC16F66 in 28-SOIC) or on the PIC16C66 JW windowed CERDIP version before committing to OTP production parts. Programming requires applying ~13V on the MCLR/Vpp pin, distinct from Vdd. Use a Microchip MPLAB PM3 or PICkit 3 programmer with the correct adapter; in-circuit programming requires isolation of MCLR/Vpp from the application circuit to avoid contention.
Add a 100 nF decoupling capacitor as close as possible to the Vdd pin (pin 26) and a bulk 10 uF tantalum or aluminum capacitor on the same supply rail. The PIC16C66-10E/SO can source/sink up to 25 mA per I/O pin with a total package limit of 200 mA; high-current loads (LEDs, relays) must be buffered with transistors or driver ICs. Place a series resistor on the MCLR/Vpp pin to limit programming-voltage inrush during production programming.
Route the crystal or resonator traces (OSC1, OSCC2, pins 15-16) short and symmetric, with a ground guard ring to minimize EMI pickup. Keep analog ADC inputs (RA0-RA5) routed away from switching digital signals; add a small RC filter (1 kohm + 100 nF) on each analog input if the source impedance exceeds 10 kohm to prevent ADC sampling distortion. The 28-SOIC package allows generous routing under the device; use a continuous ground plane under the MCU for thermal dissipation and signal integrity.
Compliance Information
Verified web data confirms automotive temperature grade but does not explicitly state RoHS/REACH compliance for the OTP PIC16C66-10E/SO; refer to Microchip material declaration documents for definitive compliance status.
