PIC16C505-20I/P - 8-bit OTP MCU, 1.5KB, 12 I/O, 20MHz | Microchip
MPN: PIC16C505-20I/P β Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $2.27 | $2.27 |
| 10 | $2.04 | $20.40 |
| 100 | $1.81 | $181.00 |
| 500 | $1.59 | $795.00 |
| 1,000 | $1.36 | $1,360.00 |
PIC16C505-20I/P Overview
A microcontroller (MCU) is a single-chip computer that combines a CPU core, program memory, working RAM, I/O peripherals and interrupt/timer subsystems on one die. The PIC16 family belongs to the 8-bit microcontroller class, sitting below 16-bit and 32-bit MCUs in compute density but offering the lowest cost, simplest toolchain, and smallest footprint for embedded control tasks. PIC16C505 specifically targets cost-sensitive, deterministic control loops where 33 single-word instructions and a 12-bit-wide opcode are sufficient.
Key features of the PIC16C505-20I/P include an internal oscillator, a Watchdog Timer (WDT) backed by a dedicated on-chip RC oscillator for reliable operation, a Device Reset Timer (DRT), Power-on Reset (POR), and In-Circuit Serial Programming (ICSP) that lets you re-flash the OTP part in place. The 12-bit instruction width yields roughly 2:1 code compression versus competing 8-bit MCUs, which lets many applications fit inside the 1 K-word OTP budget.
Architecturally, the part uses a Harvard-style bus with separate program and data paths, a 2-level hardware stack, and 8-bit-wide register file operations. The 20 MHz oscillator combined with a 4-cycle-per-instruction core produces 5 MIPS sustained throughput, more than enough for sensor polling, relay/keypad scanning, and simple PWM or timing tasks. Brown-out and power-on reset are managed internally, reducing external component count.
Typical applications include white-goods and appliance control, low-end remote-control transmitters, battery chargers with discrete analog front-ends, HVAC damper/valve actuators, simple sensor interfaces, and replacement of discrete logic in legacy industrial boards. The 14-pin PDIP form factor is convenient for prototyping, hobby projects, and through-hole assembly lines.
When designing with this part, keep VDD between 3.0 V and 5.5 V and respect the industrial temperature window. Choose the PIC16F505-I/P if you need Flash memory for re-programming during development, or PIC16C505-04I/P if your design only needs 4 MHz. This page consolidates distributor pricing, drop-in alternatives, and practical design notes that are not found in the manufacturer datasheet alone.
Drop-in alternatives for PIC16C505-20I/P 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 PIC16C505-20I/P (same form factor and footprint) β differing in Core Architecture, Package, Supply Voltage (VDD), Watchdog Timer.
Quick Comparison Tool β Select alternative parts for side-by-side comparison:
PIC16F505-I/P
β Drop-Inπ Reference alternative (not in catalog)
PIC16C505-04I/P
β Drop-Inπ Reference alternative (not in catalog)
PIC16C505-20I/P Maximum Ratings & Electrical Characteristics
| Core Architecture | PIC16 (8-bit RISC) |
| Program Memory Size | 1.5 KB (1K x 12) OTP |
| RAM Size | 72 bytes |
| Maximum Clock Frequency | 20 MHz |
| Instruction Cycle Time | 200 ns |
| Number of I/O Pins | 11 (12 per datasheet summary; 11 GPIO + 1 MCLR/RA5 multiplexed) |
| Instruction Set Size | 33 single-word instructions |
| Instruction Width | 12 bits |
| Supply Voltage (VDD) | 3.0 V to 5.5 V |
| Operating Temperature Range | -40 Β°C to +85 Β°C (industrial) |
| Oscillator Type | Internal |
| Watchdog Timer | Yes, dedicated on-chip RC oscillator |
| Reset Features | Power-on Reset (POR), Device Reset Timer (DRT) |
| Programming Interface | In-Circuit Serial Programming (ICSP) |
| Package | 14-pin PDIP (0.300", 7.62 mm) |
| Mounting Type | Through-Hole |
| RoHS Status | Compliant |
PIC16C505-20I/P Pin Configuration
| Pin 1 | VDD β Positive supply voltage (3.0 V to 5.5 V) |
| Pin 2 | OSC1/CLKIN β Oscillator input or external clock input |
| Pin 3 | OSC2/CLKOUT β Oscillator output or clock output |
| Pin 4 | MCLR/VPP/RA5 β Master Clear (reset) input / programming voltage / GPIO RA5 |
| Pin 5 | RA0 β Bidirectional I/O port A bit 0 |
| Pin 6 | RA1 β Bidirectional I/O port A bit 1 |
| Pin 7 | RA2 β Bidirectional I/O port A bit 2 |
| Pin 8 | RA3 β Bidirectional I/O port A bit 3 |
| Pin 9 | RA4 β Bidirectional I/O port A bit 4 (also T0CKI) |
| Pin 10 | VSS β Ground reference |
| Pin 11 | RB0 β Bidirectional I/O port B bit 0 (interrupt-on-change) |
| Pin 12 | RB1 β Bidirectional I/O port B bit 1 (interrupt-on-change) |
| Pin 13 | RB2 β Bidirectional I/O port B bit 2 (interrupt-on-change) |
| Pin 14 | RB3 β Bidirectional I/O port B bit 3 (interrupt-on-change) |
Typical Applications
PIC16C505-20I/P is suitable for 7 applications: White Goods and Appliance Control, Battery-Powered Remote Controls, Industrial Sensor Interface Modules, HVAC Damper and Valve Actuators, Smart Lighting and LED Drivers, Replacement of Discrete Logic in Legacy Boards, Toy and Hobby Electronics.
White Goods and Appliance Control
The PIC16C505-20I/P fits white-goods control boards because its 20 MHz core and 200 ns instruction cycle are fast enough to scan keypads, drive triac-based load switches, and run discrete PID loops for washers, dishwashers and microwave ovens. The 1.5 KB OTP program memory holds typical appliance state machines while the 11 GPIO pins are sufficient to interface relays, LEDs, and sensor inputs without external mux logic. Industrial temperature rating (-40 Β°C to +85 Β°C) tolerates under-cabinet and garage-installation environments, and the 14-pin PDIP package is friendly to high-volume through-hole assembly lines.
Recommended
Battery-Powered Remote Controls
The PIC16C505-20I/P suits low-end RF and IR remote controls thanks to its internal oscillator (no external resonator), 3.0 V minimum VDD, and PIC16 SLEEP mode that drops current draw to a few microamps between button presses. The 33-instruction PIC16 ISA lets a small 1 K-word OTP image encode long button-press, repeat, and learning sequences for TV/STB/smart-lighting remotes. 12-bit instructions compress scan-table data efficiently so debounce, IR protocol encoding (RC5/ NEC), and pairing codes all fit inside the 1.5 KB program budget.
Recommended
Industrial Sensor Interface Modules
The PIC16C505-20I/P is well-matched to 4-20 mA loop sensor transmitters, thermistor/RTD conditioning boards, and limit-switch aggregators because its 11 GPIO pins can host SPI/I2C sensor buses plus discrete alert outputs. Industrial -40 Β°C to +85 Β°C operation tolerates factory floor thermal swings, and the internal oscillator eliminates a quartz crystal that would otherwise be a vibration-failure risk on rotating equipment. The Harvard bus and deterministic interrupt latency are ideal for time-stamping sensor events at consistent intervals.
Recommended
HVAC Damper and Valve Actuators
The PIC16C505-20I/P drives HVAC zone damper and valve actuators where it interprets analog temperature input via on-chip comparator, runs a small PI control loop, and commutates a low-voltage DC motor or stepper via PWM. The 20 MHz core closes the control loop in well under 10 ms, while 11 GPIO lines provide sufficient headroom for end-stop switches, position feedback, and a 1-Wire or I2C interface to the room thermostat. Industrial temperature grade handles plenum-box ambient temperatures near 85 Β°C.
Recommended
Smart Lighting and LED Drivers
The PIC16C505-20I/P can replace discrete 555-timer-based circuits in LED controllers, decorative light chasers, and emergency-fixture self-test managers. Its PWM capability combined with 11 GPIO lets it drive multiple LED channels via external MOSFETs while reading ambient-light sensors and push-buttons. The OTP-only memory locks the firmware against unauthorized pattern copy in commercial lighting products, and the 3.0 V minimum VDD lets it run from small buck converters fed by the LED driver supply rail.
Recommended
Replacement of Discrete Logic in Legacy Boards
The PIC16C505-20I/P is a popular retrofit for legacy 74HC-series glue-logic boards because it consolidates dozens of gates, flip-flops, and timer ICs into one 14-pin part, simplifying board layout and improving reliability. Its 200 ns instruction cycle matches the propagation delays of older CMOS logic, so it can emulate debounce circuits, monostables, frequency dividers, and shift-register scan chains in software. Industrial temperature rating and PDIP package make it a clean drop-in for older through-hole equipment still in field service.
Recommended
Toy and Hobby Electronics
The PIC16C505-20I/P fits hobby robotics, model-train controllers, and educational electronics kits because the 14-pin PDIP is breadboard-friendly and Microchip's MPLAB X IDE with free XC8 C compiler supports the PIC16C family. The 33-instruction ISA is small enough to teach assembly fundamentals, while C code on the 5 MIPS core handles sensor reads, motor PWM, and serial debug output. The industrial temperature grade tolerates outdoor and garage workshop environments encountered in hobby use.
Recommended
Recommended Products Summary
Engineering reference data for PIC16C505-20I/P β comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16F505-I/P | PIC16C505-04I/P | PIC16C505-20I/SL | PIC12F629-I/P |
|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 14-pin PDIP | 14-pin PDIP (same) | 14-pin PDIP (same) | 14-pin SOIC-14 (different) | 8-pin PDIP (different) |
| Program Memory | 1.5 KB OTP | 1.5 KB Flash | 1.5 KB OTP | 1.5 KB OTP | 1 KB Flash |
| RAM Size | 72 bytes | 72 bytes | 72 bytes | 72 bytes | 64 bytes |
| Max Clock Frequency | 20 MHz | 20 MHz | 4 MHz | 20 MHz | 20 MHz |
| I/O Pins | 11 (+ 1 multiplexed MCLR) | 11 (+ 1 multiplexed MCLR) | 11 (+ 1 multiplexed MCLR) | 11 (+ 1 multiplexed MCLR) | 6 (+ GP3/MCLR) |
| Memory Type | OTP (one-time programmable) | Flash (re-programmable) | OTP | OTP | Flash |
| Operating Temperature | -40 Β°C to +85 Β°C (industrial) | -40 Β°C to +85 Β°C (industrial) | -40 Β°C to +85 Β°C (industrial) | -40 Β°C to +85 Β°C (industrial) | -40 Β°C to +85 Β°C (industrial) |
| Unit Price (1-pc, as of 2026-09-16) | $2.27 | Slightly higher (Flash die) | Similar to 20 MHz part | Similar to PDIP | Lower (smaller die) |
Key Differentiators
- Industrial-grade OTP at 20 MHz in 14-pin PDIP (vs PIC16C505-04I/P)
- OTP die with locked firmware vs Flash reprogrammability (vs PIC16F505-I/P)
- Through-hole PDIP-14 package (vs PIC16C505-20I/SL)
Design Notes
PIC16C505-20I/P operates from 3.0 V to 5.5 V on VDD. Place a 100 nF decoupling capacitor as close as possible to the VDD pin (pin 1) with a short trace to VSS (pin 10). For designs with high dI/dt loads (relay coils, LEDs), add a 10 Β΅F bulk capacitor on the same rail. The internal oscillator eliminates the external resonator and its associated start-up current, simplifying power-supply design versus crystal parts. Estimated: at 20 MHz with all I/O static and SLEEP disabled, core current is roughly 2-3 mA at 5 V.
Use a star-ground topology tying VSS pin 10 to a single ground pour to keep digital switching currents out of analog reference paths. Keep the MCLR/VPP/RA5 pin (pin 4) trace short; if you do not need external reset, tie it directly to VDD through a 10 kΞ© resistor. Route OSC1 and OSC2 with matched lengths if you add an external resonator or canned oscillator, and keep oscillator traces away from RB port switching lines to avoid injection-locking or EMI coupling.
Do not confuse the -20I/P suffix: "20" means 20 MHz maximum clock, "I" means industrial -40 Β°C to +85 Β°C, and "/P" means PDIP-14 package. Using the part above 20 MHz violates AC timing specs and may cause intermittent failures. The OTP memory cannot be erased - once you commit code in production, every code change requires a new mask or a Flash-based sibling (PIC16F505-I/P). Always reserve the MCLR/VPP pin for in-circuit serial programming access during development.
The PIC16C505-20I/P in PDIP-14 has no significant self-heating; power dissipation is dominated by I/O sink/source current rather than core consumption. Estimated: with all 11 GPIO sourcing 5 mA at 5 V into LEDs, total dissipation is roughly 275 mW. This stays well below the 14-pin PDIP thermal limit even at 85 Β°C ambient, but you should still de-rate I/O current to 4 mA per pin if multiple pins switch simultaneously per Microchip's absolute maximum ratings.
Compliance Information
RoHS and REACH compliance per Microchip product page. AEC-Q100 qualification not offered for PIC16C505 family. Lead finish confirmed lead-free per Microchip packaging information; halogen-free status not stated in available data.
