PIC16C505-04I/SL - 8-Bit 4MHz OTP MCU, 1.5KB, 12 I/O | Microchip
MPN: PIC16C505-04I/SL β End of Life| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $0.9 | $0.90 |
| 10 | $0.85 | $8.50 |
| 100 | $0.75 | $75.00 |
| 500 | $0.68 | $340.00 |
| 1,000 | $0.6 | $600.00 |
PIC16C505-04I/SL Overview
What is an OTP microcontroller? An OTP (One-Time-Programmable) microcontroller is a class of MCU whose program memory is implemented using EPROM cells that can be written exactly once during production or field programming, then cannot be erased. OTP MCUs sit in the hierarchy: microcontroller -> embedded processor -> semiconductor IC. They offer lower per-unit cost than flash-based MCUs and are commonly used in high-volume, code-stable consumer and industrial products where in-field firmware updates are not required.
Key features include the PIC16C5x baseline RISC architecture with only 33 single-word/single-cycle instructions, providing typical 2:1 code compression over competing 8-bit MCUs. The device supports 8-bit-wide data paths, hardware stack, and direct/indirect addressing modes. An internal RC oscillator option reduces BOM cost, while the Watchdog Timer (WDT) and Power-on Reset (POR) enhance field reliability. The industrial-grade (-40C to +85C) operating range supports harsh-environment deployments.
The PIC16C505-04I/SL employs a Harvard-architecture RISC core that executes one instruction per clock cycle (except branches), achieving 200 ns instruction time at 4 MHz. The 12-bit instruction word is symmetric, simplifying code generation. Internal peripherals are mapped to a compact register file, and the device supports in-circuit serial programming (ICSP) via RB6/RB7 pins for production-line code loading.
Typical applications include low-cost consumer appliances, small industrial control modules, sensor signal conditioning front-ends, simple LED driving controllers, remote control transmitters, and replacement of discrete logic in cost-sensitive embedded designs. The 14-pin SOIC footprint is widely accepted in through-hole-style surface-mount assembly, simplifying PCB layout for legacy upgrades.
When designing with the PIC16C505-04I/SL, remember that OTP memory cannot be re-programmed; prototype using the PIC16F505 (Flash-based) variant and migrate to the PIC16C505 for production cost savings. Ensure RB6/RB7 are accessible for in-circuit serial programming during manufacturing, and budget decoupling capacitors per the datasheet typical application circuit.
This page synthesizes distributor pricing, drop-in compatible alternatives from the same PIC16C5x family, and practical design notes not found in the manufacturer datasheet alone.
Drop-in alternatives for PIC16C505-04I/SL 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 PIC16C505-04I/SL (same form factor and footprint) β differing in Core Architecture, In-Circuit Serial Programming (ICSP), Package, Program Memory Type, Timers.
Quick Comparison Tool β Select alternative parts for side-by-side comparison:
PIC16F505-I/SL
β Drop-Inπ Reference alternative (not in catalog)
PIC16C505-04/SL
β Drop-Inβ In Stock
$1.05 / Unit
View Datasheet βPIC16C505-20I/SL
β Drop-In β οΈ εζ°εΎ ιͺθ―π Reference alternative (not in catalog)
PIC16C505-04I/P
β Drop-In β οΈ εζ°εΎ ιͺθ―π Reference alternative (not in catalog)
PIC16C505T-04I/SL
β Drop-Inπ Reference alternative (not in catalog)
PIC16LC505-04I/SL
β Drop-Inπ Reference alternative (not in catalog)
PIC16F505T-I/SL
β Drop-Inπ Reference alternative (not in catalog)
PIC16C505-04I/SL Maximum Ratings & Electrical Characteristics
| Core Architecture | PIC16C5x (8-bit RISC, Harvard) |
| Program Memory Type | OTP (One-Time-Programmable EPROM) |
| Program Memory Size | 1.5 KB (1K x 12) |
| RAM Size | 72 bytes |
| Maximum Clock Frequency | 4 MHz |
| Instruction Cycle Time | 200 ns |
| Instruction Set | 33 single-word/single-cycle instructions |
| Data Bus Width | 8-bit |
| I/O Pins | 12 |
| Timers | 1 x 8-bit Timer/Counter |
| Watchdog Timer (WDT) | Yes |
| Brown-out Reset / POR | Power-on Reset (POR) |
| Oscillator | External crystal/RC or internal RC |
| In-Circuit Serial Programming (ICSP) | Yes (via RB6/RB7) |
| Operating Temperature Range | -40C to +85C (Industrial) |
| Package Type | 14-pin SOIC (SL) |
| Mounting Type | Surface Mount |
| RoHS Status | Compliant |
| Lead-Free | Yes |
PIC16C505-04I/SL Pin Configuration
| Pin 1 | RA2 β Bidirectional I/O port A bit 2 |
| Pin 2 | RA3 β Bidirectional I/O port A bit 3 |
| Pin 3 | RA4/T0CKI β Bidirectional I/O port A bit 4 / Timer0 clock input |
| Pin 4 | MCLR β Master Clear reset input (active low) |
| Pin 5 | VSS β Ground reference |
| Pin 6 | RB0/INT β Bidirectional I/O port B bit 0 / External interrupt |
| Pin 7 | RB1 β Bidirectional I/O port B bit 1 |
| Pin 8 | RB2 β Bidirectional I/O port B bit 2 |
| Pin 9 | RB3 β Bidirectional I/O port B bit 3 |
| Pin 10 | RB4 β Bidirectional I/O port B bit 4 |
| Pin 11 | RB5 β Bidirectional I/O port B bit 5 |
| Pin 12 | RB6/ICSPCLK β Bidirectional I/O port B bit 6 / ICSP clock |
| Pin 13 | RB7/ICSPDAT β Bidirectional I/O port B bit 7 / ICSP data |
| Pin 14 | VDD β Positive supply voltage |
Typical Applications
PIC16C505-04I/SL is suitable for 6 applications: Consumer Appliance Control, Remote Control Transmitter, Industrial Sensor Signal Conditioning, LED Lighting Controller, Replacement of Discrete Logic, Small Industrial Control Modules.
Consumer Appliance Control
The PIC16C505-04I/SL fits low-cost consumer appliance controllers (rice cookers, washing-machine sub-modules, fan speed controllers) where firmware is code-frozen after development and OTP memory is acceptable. Its 4 MHz core executes control logic in 200 ns per instruction, fast enough for relay sequencing, LED driving, and basic sensor polling. The 12 I/O pins directly drive seven-segment displays, keypad matrices, and triac control lines without external glue logic. Industrial -40C to +85C operation handles kitchen and laundry environments. Cost-optimized OTP eliminates the need for flash memory, reducing per-unit BOM cost below $0.70 at 1000-piece quantity, making it ideal for high-volume appliances where the design is finalized.
Recommended
Remote Control Transmitter
The PIC16C505-04I/SL is well suited for IR/RF remote control transmitters because its 8-bit core encodes standard NEC/RC-5 protocols in firmware with minimal overhead. The 4 MHz instruction cycle produces accurate 38 kHz carrier timing for IR transmission, while 72 bytes of RAM easily holds protocol state and button-debounce variables. The 12 I/O pins scan 4x4 matrix keypads and drive a single IR LED through an external transistor. Low-power standby is achieved by halting the oscillator, with the Watchdog Timer providing wake-up. The SOIC-14 footprint fits inside slim remote-control enclosures, and OTP memory prevents firmware reverse-engineering by competitors.
Recommended
Industrial Sensor Signal Conditioning
The PIC16C505-04I/SL operates as a smart front-end for industrial sensor signal conditioning modules, digitizing analog signals via on-chip comparator plus software ADC and transmitting results via UART-software or PWM encoding. Its industrial -40C to +85C temperature range handles factory-floor environments, while the Watchdog Timer and Power-on Reset ensure unattended recovery from brownouts. The 4 MHz instruction speed supports 8-bit sigma-delta conversion with 1 kHz effective sample rate. The 14-pin SOIC footprint suits compact DIN-rail sensor modules, and OTP memory locks calibration coefficients at production preventing field tampering with sensor linearity data.
Recommended
LED Lighting Controller
The PIC16C505-04I/SL drives LED lighting controllers with PWM dimming and color-mixing logic in cost-sensitive architectural and signage installations. Its 8-bit timer generates 8-bit PWM dimming signals on any I/O pin, controlling LED current via external MOSFETs without dedicated PWM peripherals. With 12 I/O pins, the MCU drives three RGB channels (9 PWM pins) plus three control inputs for mode selection and brightness. Industrial temperature rating covers outdoor signage and architectural lighting. OTP memory locks color-temperature calibration firmware at production for consistent fixture-to-fixture appearance, critical for architectural installations where uniformity is required.
Recommended
Replacement of Discrete Logic
The PIC16C505-04I/SL replaces discrete 74-series logic gates, counters, and state machines in legacy industrial designs, reducing PCB area and BOM count. A single 14-pin SOIC replaces dozens of discrete logic ICs implementing timers, counters, sequencers, and protocol converters. The 4 MHz core executes complex logic sequences in firmware, while 12 I/O pins handle all signal fan-out. Industrial -40C to +85C rating matches factory-automation environment specs. OTP memory protects proprietary control algorithms from unauthorized cloning. Migration from 74HC logic to the PIC16C505 typically cuts PCB area by 60-80% and reduces unit cost in volumes above 1000 pieces.
Recommended
Small Industrial Control Modules
The PIC16C505-04I/SL embeds control logic in small industrial modules such as relay drivers, motor speed controllers, and process timers. The 8-bit timer generates accurate timing intervals up to several seconds with software prescalers, while 12 I/O pins drive multiple relays, optocouplers, and status LEDs. Industrial -40C to +85C temperature range tolerates control-cabinet environments, and the Watchdog Timer plus Power-on Reset ensure unattended operation recovers from ESD-induced lockups. The 14-pin SOIC package drops into existing 74-series logic footprints or custom modules. OTP memory prevents unauthorized firmware cloning in machine-builder supply chains.
Recommended
Recommended Products Summary
Engineering reference data for PIC16C505-04I/SL β comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16F505-I/SL | PIC16C505-04/SL | PIC16LC505-04I/SL | PIC16C505T-04I/SL | PIC16F505T-I/SL |
|---|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 14-SOIC (SL) | 14-SOIC (SL) - same | 14-SOIC (SL) - same | 14-SOIC (SL) - same | 14-SOIC (SL) - same | 14-SOIC (SL) - same |
| Program Memory Type | OTP EPROM (1.5 KB) | Flash (1.5 KB) | OTP EPROM (1.5 KB) | OTP EPROM (1.5 KB) low-voltage | OTP EPROM (1.5 KB) | Flash (1.5 KB) |
| Maximum Clock Frequency | 4 MHz | 4 MHz | 4 MHz | 4 MHz | 4 MHz | 4 MHz |
| Operating Temperature Range | -40C to +85C (Industrial) | -40C to +85C (Industrial) | 0C to +70C (Commercial) | -40C to +85C (Industrial) | -40C to +85C (Industrial) | -40C to +85C (Industrial) |
| Lifecycle Status | NRND | Active | NRND | NRND | NRND | Active |
| Approx. Unit Price (1k qty) | $0.60 USD | $0.95 USD | $0.55 USD | $0.70 USD | $0.60 USD | $0.95 USD |
Key Differentiators
- OTP EPROM cost advantage in high-volume production (vs PIC16F505-I/SL)
- Industrial temperature rating (vs PIC16C505-04/SL)
- Low-voltage variant for battery operation (vs PIC16LC505-04I/SL)
- Pin-compatible migration path to Flash (vs All Microchip PIC16C5x OTP family)
Design Notes
Estimated: Prototype using PIC16F505-I/SL (Flash, same 14-pin SOIC footprint) before committing to PIC16C505-04I/SL OTP for production. OTP memory cannot be erased - a firmware bug discovered after programming requires scrapping the entire silicon lot. The Flash variant lets you iterate firmware up to thousands of times. Once firmware is code-frozen and validated, migrate to the OTP variant for cost savings in volume production.
Reserve access to pins 12 and 13 (RB6/ICSPCLK and RB7/ICSPDAT) on the PCB for in-circuit serial programming during manufacturing. The ICSP interface requires 5V-tolerant signal lines and a 4.7 kohm pull-up on MCLR (pin 4) per Microchip programming specifications. If these pins are inaccessible after board assembly, factory programming via ICSP becomes impossible and you must program the OTP before soldering, which complicates inventory and field service.
Estimated: Place a 100 nF decoupling capacitor as close as possible to VDD (pin 14) and a 10 uF bulk capacitor near the supply input. The PIC16C505-04I/SL draws approximately 2 mA active at 4 MHz and 1 uA standby. Add 0.1 uF + 10 uF decoupling to handle digital switching transients. For battery-powered applications, use the internal RC oscillator and watchdog timer to achieve <2 uA average current consumption.
Keep the external crystal or ceramic resonator traces short and symmetrical (within 2 mm of pins OSC1/OSC2 when used) to avoid EMI and frequency drift. For PCB layouts with mixed analog/digital signals, separate the MCLR reset trace from high-current switching lines. The 14-pin SOIC allows reasonable ground-plane routing on the top layer; place a continuous ground pour on the bottom layer connected to VSS (pin 5).
Compliance Information
RoHS compliant per Microchip product page. Not AEC-Q100 qualified (consumer/industrial grade only). Lead-free and halogen-free per Microchip environmental compliance documentation. Lifecycle status NRND per Microchip product change notification.
