PIC16C66T-10E/SO - 8-Bit OTP MCU, 14KB, 10MHz, 28-SOIC
MPN: PIC16C66T-10E/SO ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $8.92 | $8.92 |
| 10 | $8.1 | $81.00 |
| 100 | $7.2 | $720.00 |
| 500 | $6.45 | $3,225.00 |
| 1,000 | $5.8 | $5,800.00 |
PIC16C66T-10E/SO Overview
A microcontroller (MCU) is a single-chip computer that contains a processor core, program and data memory, peripherals, and I/O. Within the broader taxonomy, the PIC16C66 belongs to the 8-bit microcontroller class -> RISC microcontroller sub-class -> PIC16C OTP family, sitting at the intersection of embedded control and general-purpose computation. The PIC16C6X family uses a Harvard architecture with separate program and data buses, 35 single-word instructions, and an instruction set optimized for compiled C and hand-written assembly.
Key features include a maximum 10 MHz external clock (200 ns instruction cycle, except 2-cycle branches), hardware peripherals such as two 8-bit timers, one 16-bit timer, a Watchdog Timer (WDT), PWM module, Brown-out Detect/Reset (BOR), Power-on Reset (POR), a 10-bit ADC, and three serial interfaces (I2C/SPI, USART). The OTP program memory is windowless and is programmed once with a device programmer, suiting cost-sensitive production runs that do not require firmware updates.
Architecturally, the PIC16C66 uses a 14-bit wide program word and an 8-bit data path, with 8-level deep hardware stack and 4 banks of register file. The 22 I/O pins are arranged across PORTA, PORTB, PORTC, and a partial PORTD, each with individually programmable direction registers. The industrial/automotive temperature grade (-40C to +125C) and CMOS low-power design (typical < 2 mA run current at 5 V / 10 MHz) make the part well suited to harsh-environment control loops.
Typical applications include automotive body and chassis control modules, industrial motor drives, sensor signal conditioning, HVAC control, and battery-powered instrumentation. The combination of OTP memory, USART, and PWM is particularly well-matched to closed-loop control of solenoids, valves, and small DC actuators.
When designing with this device, allocate a 5 V +/- 10% rail for VDD and reserve a decoupling ceramic of 0.1 uF within 5 mm of the supply pin. A 4 MHz to 10 MHz crystal with two load capacitors is required for the oscillator; ceramic resonator configurations are also supported per the datasheet.
This page consolidates distributor pricing, same-family and cross-brand drop-in alternatives, application guidance, and engineering design notes that go beyond the manufacturer datasheet to accelerate component selection.
Drop-in alternatives for PIC16C66T-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 PIC16C66T-10E/SO (same form factor and footprint) — differing in Package, ADC, Family, Watchdog Timer, Timers.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC16C66T-10/SO
✅ Drop-In✓ In Stock
$5.2 / Unit
View Datasheet →PIC16C66-10I/SO
✅ Drop-In📋 Reference alternative (not in catalog)
PIC16C66-20I/SO
✅ Drop-In✓ In Stock
$6.42 / Unit
View Datasheet →PIC16C66-04I/SO
✅ Drop-In✓ In Stock
$5.1 / Unit
View Datasheet →PIC16C66-20I/SP
✅ Drop-In✓ In Stock
$6.3 / Unit
View Datasheet →PIC16C66T-10E/SO Maximum Ratings & Electrical Characteristics
| Core Architecture | 8-bit PIC16 RISC, Harvard |
| Family | PIC16C6X |
| Program Memory | 14 KB (8K x 14) OTP |
| Data RAM | 368 bytes |
| Maximum Clock Frequency | 10 MHz |
| Instruction Cycle Time | 200 ns (single-cycle, except branches) |
| Supply Voltage (VDD) | 4.5 V to 5.5 V |
| I/O Pins | 22 |
| Timers | 2 x 8-bit, 1 x 16-bit |
| ADC | None integrated (per data snippet); analog comparator on chip |
| PWM | Yes (1 channel, 10-bit resolution per family datasheet) |
| Watchdog Timer (WDT) | Yes |
| Brown-out Detect / Reset (BOR) | Yes |
| Power-on Reset (POR) | Yes |
| Serial Communication | I2C/SPI, USART |
| Operating Temperature Range | -40C to +125C (Automotive / E grade) |
| Package | 28-pin SOIC (SO), wide-body, tape and reel |
| Pin Count | 28 |
| Mounting Type | Surface Mount |
| MSL Level | 1 |
| RoHS Status | Compliant (per active lifecycle status) |
PIC16C66T-10E/SO Pin Configuration
| Pin 1 | MCLR/VPP — Master Clear (reset) input / programming voltage |
| Pin 2 | RA0 — PORTA bit 0 (digital I/O) |
| Pin 3 | RA1 — PORTA bit 1 (digital I/O) |
| Pin 4 | RA2 — PORTA bit 2 (digital I/O) |
| Pin 5 | RA3 — PORTA bit 3 (digital I/O) |
| Pin 6 | RA4/T0CKI — PORTA bit 4 / Timer 0 clock input (open-drain) |
| Pin 7 | RA5/SS — PORTA bit 5 / SPI slave select |
| Pin 8 | VSS — Ground |
| Pin 9 | OSC1/CLKIN — Oscillator crystal input / external clock in |
| Pin 10 | OSC2/CLKOUT — Oscillator crystal output / clock out |
| Pin 11 | RC0 — PORTC bit 0 (digital I/O) |
| Pin 12 | RC1 — PORTC bit 1 (digital I/O) |
| Pin 13 | RC2/CCP1 — PORTC bit 2 / CCP1 (PWM / capture / compare) |
| Pin 14 | RC3 — PORTC bit 3 (digital I/O) |
| Pin 15 | RC4 — PORTC bit 4 (digital I/O) |
| Pin 16 | RC5 — PORTC bit 5 (digital I/O) |
| Pin 17 | RC6/TX/CK — PORTC bit 6 / USART TX / clock |
| Pin 18 | RC7/RX/DT — PORTC bit 7 / USART RX / data |
| Pin 19 | VSS — Ground |
| Pin 20 | VDD — Positive supply (4.5 V to 5.5 V) |
| Pin 21 | RB0/INT — PORTB bit 0 / external interrupt |
| Pin 22 | RB1 — PORTB bit 1 (digital I/O) |
| Pin 23 | RB2 — PORTB bit 2 (digital I/O) |
| Pin 24 | RB3 — PORTB bit 3 (digital I/O) |
| Pin 25 | RB4 — PORTB bit 4 (digital I/O / interrupt-on-change) |
| Pin 26 | RB5 — PORTB bit 5 (digital I/O / interrupt-on-change) |
| Pin 27 | RB6/PGC — PORTB bit 6 / ICSP clock (also interrupt-on-change) |
| Pin 28 | RB7/PGD — PORTB bit 7 / ICSP data (also interrupt-on-change) |
Typical Applications
PIC16C66T-10E/SO is suitable for 6 applications: Automotive Body and Chassis Control, Industrial Motor Speed Control, HVAC Fan and Damper Control, Smart Sensor Signal Conditioning, Battery-Powered Instrumentation, White Goods and Home Appliance Control.
Automotive Body and Chassis Control
The PIC16C66T-10E/SO is well suited to automotive body and chassis control modules (such as mirror controllers, wiper timing, and interior lighting drivers) because of its -40C to +125C automotive temperature grade, on-chip BOR/POR for safe crank-cold-start behaviour, and 22 I/O lines that can directly drive relay coils and low-side MOSFET switches. The 5 V supply matches the vehicle's regulated accessory rail, and the USART supports LIN-bus slave communication with a small external transceiver. Compared with newer flash PIC16F parts, the OTP memory is acceptable here because the firmware is mature and locked at production. The 10 MHz / 200 ns instruction cycle is fast enough to scan 8-16 input buttons at sub-10 ms latency and run a 100 Hz PID loop on a seat-position actuator without leaving headroom for code.
Recommended
Industrial Motor Speed Control
In low-power industrial motor speed controllers (small DC brush or unipolar stepper drives under 50 W), the PIC16C66T-10E/SO delivers the 10-bit PWM channel plus two 8-bit timers needed to generate complementary drive waveforms, sense back-EMF through the analog comparator, and implement closed-loop speed regulation. The 22 I/O lines are sufficient to drive a 4-phase stepper with a discrete H-bridge and accept quadrature encoder feedback. The 5 V supply and automotive temperature grade give this part an unusually wide environmental envelope for a 14 KB OTP MCU, which simplifies the bill of materials when the same board layout is reused across industrial and automotive product variants.
Recommended
HVAC Fan and Damper Control
The PIC16C66T-10E/SO fits HVAC fan and damper actuators where the controller runs a closed-loop temperature set-point and modulates a 24 VAC damper motor through a triac. The hardware USART supports Modbus RTU over RS-485 with an external transceiver, which is the dominant industrial HVAC fieldbus. Brown-out detect and power-on reset prevent false triac firing during brown-out conditions, an important safety consideration. The automotive temperature grade is more than enough for plenum-mounted controls that may see +85C air, and the 14 KB OTP holds the look-up tables, PID loop, and Modbus handler without needing external EEPROM.
Recommended
Smart Sensor Signal Conditioning
The PIC16C66T-10E/SO functions as a smart-sensor front-end that digitizes a 0-5 V analog signal (via external ADC or internal analog comparator), applies linearization in firmware, and outputs the calibrated value over USART or I2C. With 14 KB of OTP, designers can pack linearization, calibration, and a Modbus or custom protocol handler without an external EEPROM. The wide operating temperature range lets the same hardware serve industrial, agricultural, and automotive sensor modules. USART or I2C at the pins allows direct connection to a host PLC, display, or gateway MCU.
Recommended
Battery-Powered Instrumentation
In battery-powered instrumentation such as portable gas detectors, hand-held multimeters, or wireless remote keyless entry (RKE) transmitters, the PIC16C66T-10E/SO Sleep mode draws < 1 uA, and the WDT wakes the part periodically to read sensors and transmit over USART. The 5 V rail is straightforward to generate from a 9 V battery through an MCP1700 LDO, and the 22 I/O lines can directly drive a piezo buzzer, an LCD, and a 4-button keypad. The 14 KB OTP holds the keypad debouncer, sensor linearization, and a low-duty-cycle RF encoder for sub-GHz transmit.
Recommended
White Goods and Home Appliance Control
The PIC16C66T-10E/SO is a common choice for white-goods control boards (washing machines, dishwashers, microwave ovens, induction cooktops) where the MCU must run a user interface, drive a relay matrix, and time motor sequences. The 22 I/O lines can scan a 4x4 matrix keypad, drive a 7-segment display through external transistors, and switch 8-12 relay coils. The PWM module controls a buzzer for user feedback. With the 14 KB OTP, designers can hold the entire appliance state machine plus factory-test routines in a single chip, and the automotive temperature grade ensures reliability in the high-heat environment behind a dishwasher or oven fascia.
Recommended
Recommended Products Summary
Engineering reference data for PIC16C66T-10E/SO — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16C66T-10/SO | PIC16C66-10I/SO | PIC16C66-20I/SO | PIC16C66-04I/SO |
|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 28-SOIC (wide-body) | 28-SOIC (wide-body) | 28-SOIC (wide-body) | 28-SOIC (wide-body) | 28-SOIC (wide-body) |
| Core / Architecture | 8-bit PIC16 RISC | 8-bit PIC16 RISC | 8-bit PIC16 RISC | 8-bit PIC16 RISC | 8-bit PIC16 RISC |
| Program Memory | 14 KB OTP | 14 KB OTP | 14 KB OTP | 14 KB OTP | 14 KB OTP |
| Data RAM | 368 bytes | 368 bytes | 368 bytes | 368 bytes | 368 bytes |
| Maximum Clock Frequency | 10 MHz | 10 MHz | 10 MHz | 20 MHz | 4 MHz |
| I/O Pins | 22 | 22 | 22 | 22 | 22 |
| Operating Temperature | -40C to +125C (Automotive / E) | 0C to +70C (Commercial) | -40C to +85C (Industrial / I) | -40C to +85C (Industrial / I) | -40C to +85C (Industrial / I) |
| Serial Interfaces | I2C/SPI, USART | I2C/SPI, USART | I2C/SPI, USART | I2C/SPI, USART | I2C/SPI, USART |
| PWM Module | Yes (10-bit, 1 channel) | Yes (10-bit, 1 channel) | Yes (10-bit, 1 channel) | Yes (10-bit, 1 channel) | Yes (10-bit, 1 channel) |
Key Differentiators
- Automotive temperature grade in the 28-SOIC wide-body package (vs PIC16C66T-10/SO)
- 10 MHz instruction throughput at 5 V (vs PIC16C66-04I/SO)
- OTP memory for locked production firmware (vs PIC16F76 (flash alternative))
Design Notes
Estimated: at VDD = 5.0 V, clock = 10 MHz, the PIC16C66T-10E/SO typically draws < 5 mA active and < 1 uA in Sleep. Place a 0.1 uF ceramic decoupling capacitor within 5 mm of pin 20 (VDD) and a 10 uF bulk cap near the supply input. The on-chip Brown-out Reset (BOR) is factory-trimmed and does not require external supervision; ensure VDD rise time is < 50 ms to avoid the BOR-hold window.
OTP memory is one-time programmable. Once a PIC16C66 is programmed, it cannot be erased. Prototype with a windowed PIC16C66 JW part or a flash-based PIC16F76 (pin-compatible) before committing the OTP code. Also, RA4 is open-drain and requires a pull-up to source high - this is the most common schematic bug when migrating from PIC16F to PIC16C.
Route OSC1/OSC2 traces short and parallel with a ground guard on one side to minimize EMI coupling into the system clock. Keep the crystal within 10 mm of the MCU and use the datasheet's load capacitor values (typically 15-33 pF) - high C values slow oscillator startup and may fail at the low end of the operating temperature range.
Pins RC6/RC7 (USART) and RB6/RB7 (ICSP) are also the ICSP programming pins. If a pull-up or pull-down is required on these pins for normal operation, keep the resistance above 10 kohm to avoid contention with the programmer's high-speed ICSP driver. A series 100 ohm on MCLR is recommended to limit programming voltage ringing.
Compliance Information
RoHS and REACH compliance status inferred from Microchip product page (active lifecycle) and industry-standard for this part number. Halogen-free status not explicitly stated in the provided web data and is marked unknown. AEC-Q100 is not specifically stated for this part - the 'E' suffix indicates an extended operating temperature grade but does not on its own confirm AEC-Q100 automotive qualification.
