PIC16C67-20/PQ - 8-Bit 20MHz 14KB OTP MCU 44-MQFP | Microchip
MPN: PIC16C67-20/PQ ✗ End of Life| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $14.5 | $14.50 |
| 10 | $12.75 | $127.50 |
| 100 | $10.95 | $1,095.00 |
| 500 | $9.2 | $4,600.00 |
| 1,000 | $7.85 | $7,850.00 |
PIC16C67-20/PQ Overview
A microcontroller (MCU) is a single-chip computer containing a CPU core, program memory, working RAM, and configurable peripherals. The PIC16C family sits within Microchip's classic mid-range 8-bit portfolio, originally launched in the 1990s as the PIC16C6X series of OTP-programmed RISC microcontrollers. These parts predate modern flash-based PIC16F devices and are typically used as replacements for legacy systems where existing firmware was written for the OTP core. The hierarchy is: PIC16C67 -> PIC16C6X family -> PIC16C mid-range 8-bit MCU -> 8-bit microcontroller -> embedded processor -> semiconductor.
Key features of the PIC16C67-20/PQ include the Harvard RISC architecture with 35 single-word instructions (most single-cycle, branches two-cycle), 8-level deep hardware stack, 14-bit instruction word, two 8-bit timers plus one 16-bit timer, a 5-channel 8-bit ADC, synchronous serial port (SSP) supporting SPI and I²C, USART with addressable RS-485 mode, watchdog timer with on-chip RC oscillator, and brown-out reset / power-on reset / power-up timer. The CMOS process delivers low-power operation suitable for battery and industrial embedded systems.
The PIC16C67-20/PQ is designed around Microchip's classic PIC mid-range architecture using a 14-bit program memory bus, separate 8-bit data bus, and dedicated peripheral registers. The 8K x 14 program word ROM is accessed through a 13-bit PC, allowing linear addressing across the 14KB OTP array. Peripherals are memory-mapped and configured through banked SFRs; the core supports hardware multiply assistance in selected derivatives.
Typical applications include industrial control and instrumentation, motor control front-ends, sensor interfacing with on-chip ADC, automotive body and chassis subsystems (when qualified per automotive spec), legacy replacement of older PIC16C55/PIC16C57 designs that require more memory and I/O, and embedded systems requiring parallel slave port expansion. The 33 I/O pins and 5 ADC channels make it well suited for measurement and control panels.
When designing with the PIC16C67-20/PQ, ensure the oscillator configuration matches the application's clock accuracy requirement - crystal, ceramic resonator, or external clock inputs are supported via OSC1/OSC2. Decoupling VDD/VSS pairs with 100 nF ceramic capacitors placed as close to the pins as possible is recommended. Programming via ICSP requires RB6/RB7 and the MCLR pin to be accessible.
This page synthesizes distributor pricing, drop-in same-brand and cross-brand alternatives within the same 44-MQFP footprint, parametric comparison data, and practical design notes that augment the manufacturer datasheet with engineering context for sourcing and selection decisions.
Drop-in alternatives for PIC16C67-20/PQ — 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 PIC16C67-20/PQ (same form factor and footprint) — differing in Maximum Clock Frequency, Core Architecture, Program Memory Size, I/O Pins, Package.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC16C67-20I/PQ
✅ Drop-In✓ In Stock
$3.62 / Unit
View Datasheet →PIC16C67-10/PQ
✅ Drop-In✓ In Stock
$3.2 / Unit
View Datasheet →PIC16C67-10E/PQ
✅ Drop-In✓ In Stock
$9.95 / Unit
View Datasheet →PIC16C66-20/PQ
✅ Drop-In📋 Reference alternative (not in catalog)
PIC16F877A-I/PQ
✅ Drop-In📋 Reference alternative (not in catalog)
PIC18F452-I/PQ
✅ Drop-In📋 Reference alternative (not in catalog)
PIC16C67-20/PQ Maximum Ratings & Electrical Characteristics
| Product Family | PIC16C |
| Core Architecture | 8-bit RISC Harvard |
| CPU | PIC16C mid-range core |
| Maximum Clock Frequency | 20 MHz |
| Program Memory Size | 14 KB (8K x 14) OTP |
| RAM Size | 368 bytes |
| Number of I/O Pins | 33 |
| Number of Timers | 3 (Timer0 8-bit + Timer1 16-bit + Timer2 8-bit) |
| ADC | 5 channels, 8-bit |
| Serial Interface | SSP (SPI / I2C) + USART |
| Operating Voltage | 3.3 V / 5 V |
| Package Type | 44-pin MQFP (Metric Quad Flat Pack) |
| Package Size | 10 mm x 10 mm |
| Program Memory Type | OTP (One-Time Programmable) EPROM |
| Mounting Type | Surface Mount |
PIC16C67-20/PQ Pin Configuration
| Pin 1 | MCLR/VPP — Master clear (reset) input / programming voltage input |
| Pin 2 | RA0/AN0 — Digital I/O / analog input channel 0 |
| Pin 3 | RA1/AN1 — Digital I/O / analog input channel 1 |
| Pin 4 | RA2/AN2 — Digital I/O / analog input channel 2 |
| Pin 5 | RA3/AN3/VREF — Digital I/O / analog input channel 3 / ADC reference voltage |
| Pin 6 | RA4/T0CKI — Digital I/O / Timer0 clock input |
| Pin 7 | RA5/AN4/SS — Digital I/O / analog input channel 4 / SPI slave select |
| Pin 8 | RE0/RD/AN5 — Digital I/O / parallel slave port read / analog input channel 5 |
| Pin 9 | RE1/WR/AN6 — Digital I/O / parallel slave port write / analog input channel 6 |
| Pin 10 | RE2/CS/AN7 — Digital I/O / parallel slave port chip select / analog input channel 7 |
| Pin 11 | VDD — Positive supply voltage (3.3V or 5V) |
| Pin 12 | VSS — Ground reference |
| Pin 13 | OSC1/CLKIN — Oscillator crystal input / external clock input |
| Pin 14 | OSC2/CLKOUT — Oscillator crystal output / clock output |
| Pin 15 | RC0/T1OSO/T1CKI — Digital I/O / Timer1 oscillator output / Timer1 clock input |
| Pin 16 | RC1/T1OSI/CCP2 — Digital I/O / Timer1 oscillator input / Capture-Compare-PWM 2 |
| Pin 17 | RC2/CCP1 — Digital I/O / Capture-Compare-PWM 1 |
| Pin 18 | RC3/SCK/SCL — Digital I/O / SPI clock / I2C clock |
| Pin 19 | RD0/PSP0 — Digital I/O / parallel slave port data bit 0 |
| Pin 20 | RD1/PSP1 — Digital I/O / parallel slave port data bit 1 |
| Pin 21 | RD2/PSP2 — Digital I/O / parallel slave port data bit 2 |
| Pin 22 | RD3/PSP3 — Digital I/O / parallel slave port data bit 3 |
| Pin 23 | RC4/SDI/SDA — Digital I/O / SPI data in / I2C data |
| Pin 24 | RC5/SDO — Digital I/O / SPI data out |
| Pin 25 | RC6/TX/CK — Digital I/O / USART transmit / USART clock |
| Pin 26 | RC7/RX/DT — Digital I/O / USART receive / USART data |
| Pin 27 | RD4/PSP4 — Digital I/O / parallel slave port data bit 4 |
| Pin 28 | RD5/PSP5 — Digital I/O / parallel slave port data bit 5 |
| Pin 29 | RD6/PSP6 — Digital I/O / parallel slave port data bit 6 |
| Pin 30 | RD7/PSP7 — Digital I/O / parallel slave port data bit 7 |
| Pin 31 | VSS — Ground reference |
| Pin 32 | VDD — Positive supply voltage (3.3V or 5V) |
| Pin 33 | RB0/INT — Digital I/O / external interrupt input |
| Pin 34 | RB1 — Digital I/O |
| Pin 35 | RB2 — Digital I/O |
| Pin 36 | RB3/PGM — Digital I/O / LVP programming input |
| Pin 37 | RB4 — Digital I/O |
| Pin 38 | RB5 — Digital I/O |
| Pin 39 | RB6/PGC — Digital I/O / ICSP clock |
| Pin 40 | RB7/PGD — Digital I/O / 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
PIC16C67-20/PQ is suitable for 7 applications: Industrial Control and Instrumentation, Legacy Replacement / Field Maintenance, Sensor Interfacing and Data Acquisition, Motor Control Front-End, Embedded HMI and Keypad Controller, Automotive Body and Chassis Subsystems (Legacy), Educational and Development Boards.
Industrial Control and Instrumentation
The PIC16C67-20/PQ fits industrial control panels because its 33 digital I/O pins, 5-channel 8-bit ADC, USART with RS-485 addressable mode, and 20 MHz RISC core enable real-time monitoring of sensors and actuators. The 14KB OTP program memory accommodates PID control loops, multi-channel scanning, and HMI keypad routines in a single chip. The wide operating voltage (3.3V/5V) tolerance suits 24V-derived industrial rails with on-board regulation. Place between sensor signal-conditioning front-ends and a master PLC or HMI display, with the USART providing isolated RS-485 communication up to several hundred meters.
Recommended
Legacy Replacement / Field Maintenance
The PIC16C67-20/PQ is the canonical replacement target when servicing 1990s-era industrial equipment, HVAC controllers, and process instruments built around PIC16C5X/PIC16C6X designs. Its byte-identical OTP firmware compatibility with the original PIC16C6X family allows direct board swaps without rewriting application code. The 44-MQFP footprint matches the original PCB land pattern so legacy through-production boards can be retrofitted. Engineers should verify MCLR/VPP access for ICSP and confirm the new OTP image matches the original firmware checksum before final programming.
Recommended
Sensor Interfacing and Data Acquisition
The PIC16C67-20/PQ is well-suited for multi-sensor data acquisition panels thanks to its integrated 5-channel 8-bit ADC, 14KB OTP program memory, and 368-byte RAM buffer. The on-chip ADC samples temperature, pressure, or position sensors at rates up to ~20 ksps when clocked at 20 MHz, with the on-chip USART streaming formatted data to a host display. Place near the sensor cluster with 100 nF ceramic decoupling on each VDD/VSS pair; external op-amps (LM358) buffer high-impedance sensor outputs before the ADC channels to maintain measurement linearity.
Recommended
Motor Control Front-End
The PIC16C67-20/PQ serves as a motor-control command processor in low-voltage stepper and brushed DC drives because of its 20 MHz RISC core, three timers (one 16-bit for PWM), 33 I/O pins, and 5-channel ADC for current sensing. The 14KB OTP memory holds trapezoidal commutation tables and soft-start profiles. Place between Hall-effect position sensors (ADC inputs) and gate-driver ICs (IR2104) that drive the power MOSFETs. Note: OTP memory prevents firmware updates; new designs should consider the flash-based PIC16F877A-I/PQ for tunable acceleration curves.
Recommended
Embedded HMI and Keypad Controller
The PIC16C67-20/PQ handles embedded human-machine interface (HMI) functions such as 4x4 keypad scanning, character LCD driving, and LED matrix control. With 33 I/O pins it can directly drive a 16-pin character LCD plus an 8x8 scanning matrix without external logic, and the 14KB OTP memory stores character fonts and menu state machines. The 20 MHz instruction rate delivers fast keypad debounce and smooth LCD updates. Pair with a HD44780-compatible LCD module and use one timer for the keypad scan ISR while the main loop refreshes the LCD.
Recommended
Automotive Body and Chassis Subsystems (Legacy)
Although the standard PIC16C67-20/PQ is commercial-temperature grade, automotive subsystems designed in the late 1990s and early 2000s sometimes used industrial-temperature PIC16C67-20I/PQ variants for body controllers, lighting modules, and seat controllers. The wide operating voltage tolerance handles 12V automotive supply transients, and the USART supports LIN-bus-style communication with external transceivers. Place between automotive sensors (temperature, position) and the BCM, with TVS diodes (P6KE33CA) on supply lines for load-dump protection per ISO 7637-2.
Recommended
Educational and Development Boards
The PIC16C67-20/PQ and its PIC16C6X family siblings are still used in university embedded-systems courses as reference designs for teaching RISC architecture, OTP programming, and assembly language. Its 35-instruction RISC core, 14-bit instruction word, and 8-level hardware stack illustrate classic accumulator-based design without modern compiler overhead. Pair with an MPLAB PM3 programmer and the PICDEM-2 development board for a complete teaching kit. Note: the obsolete OTP status means students must commit firmware before final programming - a deliberate constraint that teaches verification discipline.
Recommended
Recommended Products Summary
Engineering reference data for PIC16C67-20/PQ — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16C67-20I/PQ | PIC16C67-10/PQ | PIC16C67-10E/PQ | PIC16F877A-I/PQ | PIC18F452-I/PQ |
|---|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 44-MQFP (10x10) | 44-MQFP (10x10) - same | 44-MQFP (10x10) - same | 44-MQFP (10x10) - same | 44-MQFP (10x10) - same | 44-MQFP (10x10) - same |
| Max Clock Frequency | 20 MHz | 20 MHz | 10 MHz (-50%) | 10 MHz (-50%) | 20 MHz | 40 MHz (+100%) |
| Program Memory | 14 KB OTP | 14 KB OTP | 14 KB OTP | 14 KB OTP | 14 KB Flash (reprogrammable) | 32 KB Flash (+128%) |
| RAM | 368 bytes | 368 bytes | 368 bytes | 368 bytes | 368 bytes | 1536 bytes (+317%) |
| Number of I/O Pins | 33 | 33 | 33 | 33 | 33 | 33 |
| ADC | 5 ch x 8-bit | 5 ch x 8-bit | 5 ch x 8-bit | 5 ch x 8-bit | 8 ch x 10-bit (upgraded) | 8 ch x 10-bit (upgraded) |
| Memory Type | OTP (one-time) | OTP (one-time) | OTP (one-time) | OTP (one-time) | Flash (reprogrammable) | Flash (reprogrammable) |
| Lifecycle Status | Obsolete | Obsolete | Obsolete | Obsolete | Active | Active |
Key Differentiators
- Industry-standard legacy PIC16C6X OTP pin-compatible ecosystem (vs PIC16C67-20I/PQ)
- Active-production flash-based drop-in successor available (vs PIC16F877A-I/PQ)
- Mature 20 MHz RISC core with 35-instruction set (vs PIC16C67-10/PQ)
Design Notes
The PIC16C67-20/PQ has two VDD/VSS pairs (pins 11/12 and 31/32). Place a 100 nF ceramic decoupling capacitor within 5 mm of each VDD/VSS pair on the PCB to suppress switching noise on the internal logic. For battery-powered designs, the brown-out reset and power-on reset blocks must be enabled via configuration fuses to prevent code execution at low VDD. Bulk decoupling of 10 uF on the supply rail is also recommended. Estimated: at 20 MHz with all peripherals active, typical current draw is 15-25 mA depending on I/O loading.
Place the 44-MQFP land pattern per IPC-7351 with 0.80 mm pitch and a 12 mm x 12 mm pad array; keep oscillator traces short and surround OSC1/OSC2 (pins 13/14) with a ground guard ring to reduce EMI pickup. For crystal operation use a fundamental-mode cut crystal with 20 pF load capacitors tied to VSS. Avoid routing digital signal traces under the oscillator loop area. The MCLR pin (1) requires a 10 kohm pull-up to VDD unless the internal MCLR is enabled via configuration fuses.
Because the PIC16C67-20/PQ uses OTP (one-time programmable) EPROM, a programming error permanently destroys the device - there is no second chance. Always verify the OTP image with a Microchip MPLAB PM3 programmer's verify function before final programming, and use windowed PIC16C67 samples (CERDIP package) for firmware development. Do not exceed 25 mA per I/O pin or 200 mA per port - use external drivers (ULN2003A) for relays and LED matrices. The I2C module requires 4.7 kohm pull-ups on SCL/SDA when used in master or slave mode.
Compliance Information
Compliance status for legacy PIC16C67-20/PQ is not explicitly stated in the verified web data. Because the part was released in the 1990s, lead-based MQFP lead finishes may be present on some date codes. Engineers needing RoHS compliance should request the official compliance letter from Microchip or migrate to the RoHS-compliant flash-based PIC16F877A-I/PQ successor.
