PIC16C505-04/SL - 8-Bit 4MHz OTP MCU 1.5KB | Microchip
MPN: PIC16C505-04/SL β Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $1.64 | $1.64 |
| 10 | $1.48 | $14.80 |
| 100 | $1.32 | $132.00 |
| 500 | $1.18 | $590.00 |
| 1,000 | $1.05 | $1,050.00 |
PIC16C505-04/SL Overview
A microcontroller (MCU) is a single-chip computer that integrates a CPU, memory, and programmable I/O peripherals on one IC. The PIC16C5x family belongs to the PIC16 mid-range 8-bit microcontroller architecture, sitting hierarchically under the broader PIC microcontroller family, which itself falls under Microchip's embedded controller and 8-bit MCU product lines. 8-bit OTP microcontrollers like the PIC16C505 are commonly used in cost-sensitive, low-volume, or fixed-function applications where program memory is programmed once at production and the code never needs updating.
Key features include 33 single-word single-cycle instructions enabling compact code density (typically 2:1 over competing 8-bit MCUs), a 5-channel 8-bit A/D converter absent on this variant (digital-only I/O), and an on-chip watchdog timer with its own dedicated RC oscillator for reliable operation independent of the system clock. The PIC16C505 includes In-Circuit Serial Programming (ICSP), Power-on Reset (POR), Device Reset Timer (DRT), and a programmable code-protection mechanism for IP security. Its RISC architecture and Harvard bus design separate program and data memory paths, allowing instruction fetch and operand access to occur in the same cycle.
Typical applications include low-cost consumer appliances, remote controls, sensor interface front-ends, LED driver controllers, battery-powered toys, and simple industrial timer/counter modules. The wide 2.5V to 5.5V operating range supports both 3.3V and 5V system designs, and 12 I/O pins provide enough headroom for keypad scanning, display multiplexing, and serial-bit-banged communication.
When designing with this device, observe that the OTP memory cannot be re-programmed - choose this part for production-fixed code, or evaluate the flash-based PIC16F505 for development/field-upgradable designs. The PIC16C505 is a member of the legacy PIC16C5x family; for new designs, Microchip generally recommends the PIC16F505 (flash) or PIC10/12F successor families.
Drop-in alternatives for PIC16C505-04/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 PIC16C505-04/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:
PIC16C505-04I/SL
β Drop-Inβ In Stock
$0.6 / Unit
View Datasheet βPIC16C505-04E/SL
β Drop-Inβ In Stock
$1.38 / Unit
View Datasheet βPIC16C505-20/SL
β Drop-In β οΈ εζ°εΎ ιͺθ―π Reference alternative (not in catalog)
PIC16C505-20I/SL
β Drop-In β οΈ εζ°εΎ ιͺθ―π Reference alternative (not in catalog)
PIC16F505-I/SL
β Drop-Inπ Reference alternative (not in catalog)
PIC16C505-04/SL Maximum Ratings & Electrical Characteristics
| Product Type | 8-bit OTP Microcontroller (MCU) |
| Family | PIC16C5x |
| Core Architecture | PIC16 RISC, Harvard |
| Maximum CPU Frequency | 4 MHz |
| Instruction Cycle Time | 200 ns |
| Program Memory (OTP) | 1.5 KB (1K x 12 words) |
| Data RAM | 72 bytes |
| Digital I/O Pins | 12 |
| Instruction Set Size | 33 single-word instructions |
| Watchdog Timer | Yes (with dedicated on-chip RC oscillator) |
| In-Circuit Serial Programming (ICSP) | Yes |
| Power-on Reset (POR) | Yes |
| Device Reset Timer (DRT) | Yes |
| Code Protection | Programmable |
| Package | 14-pin SOIC (SL) |
| Terminal Pitch | 1.27 mm |
| Mounting Type | Surface Mount |
PIC16C505-04/SL Pin Configuration
| Pin 1 | VSS β Ground reference |
| Pin 2 | OSC1/CLKIN β Oscillator crystal input or external clock input |
| Pin 3 | OSC2/CLKOUT β Oscillator crystal output; in RC mode, outputs 1/4 of CLK_IN |
| Pin 4 | /MCLR/VPP β Master clear (reset) input / programming voltage input |
| Pin 5 | GP0 β Bidirectional digital I/O pin 0 |
| Pin 6 | GP1 β Bidirectional digital I/O pin 1 |
| Pin 7 | GP2/T0CKI β Bidirectional digital I/O pin 2; Timer0 clock input |
| Pin 8 | GP3 β Bidirectional digital I/O pin 3 (input-only on this pin) |
| Pin 9 | GP4 β Bidirectional digital I/O pin 4 |
| Pin 10 | GP5 β Bidirectional digital I/O pin 5 |
| Pin 11 | NC β Not connected (no internal bond) |
| Pin 12 | NC β Not connected (no internal bond) |
| Pin 13 | VDD β Positive power supply |
| Pin 14 | VDD β Positive power supply (tied to pin 13 internally) |
Typical Applications
PIC16C505-04/SL is suitable for 6 applications: Remote Control Handsets, Battery-Powered Consumer Toys, Industrial Timer and Counter Modules, LED Lighting Controllers, Sensor Interface Front-Ends, Smart Home Edge Nodes.
Remote Control Handsets
The PIC16C505-04/SL fits IR remote control designs because its 1.5 KB OTP program memory is more than adequate for IR protocols (RC5, NEC, SIRC), its 12 I/O pins support 8-10 button matrix keypads plus an IR LED driver output, and the 200 ns instruction cycle handles modulation timing with no timing jitter. Its 4 MHz internal-execution capability ensures consistent 38 kHz carrier generation. The 14-pin SOIC footprint keeps the PCB compact inside a slim handset housing, and the OTP memory prevents code theft at production volume.
Recommended
Battery-Powered Consumer Toys
Low-cost toys with blinking LEDs, sound effects, or simple motor sequencing are an ideal fit for the PIC16C505-04/SL. The 12 digital I/O pins can directly drive multiple LEDs, piezo buzzers, or small DC motor bridges without external drivers, and the wide operating voltage range supports 2-3 cell battery packs. OTP memory keeps unit cost low for high-volume toy manufacturing, while the integrated watchdog timer with its own RC oscillator ensures the toy recovers from battery brown-out conditions.
Recommended
Industrial Timer and Counter Modules
The PIC16C505-04/SL is well suited for industrial relay-timer, event-counter, or process-interval modules in factory automation environments. Its 12 I/O pins accept digital sensor inputs (photoelectric sensors, proximity switches, dry contacts) and drive relay coils, SSR triggers, or indicator LEDs. The hardware watchdog timer with dedicated RC oscillator provides failsafe operation even if the system clock is disturbed by EMI, and code-protection prevents unauthorized firmware cloning of the timer IP.
Recommended
LED Lighting Controllers
LED controllers for decorative lighting, channel-letter drivers, or simple architectural dimmers benefit from the PIC16C505-04/SL's 12 I/O pins, which can PWM-drive 4-6 LED channels via bit-banged software PWM at the 200 ns instruction cycle, or hard-multiplex larger LED matrices. The OTP memory locks in the lighting sequence to prevent tampering or warranty invalidation in commercial lighting installations. Operating temperature range supports both indoor and semi-outdoor fixtures.
Recommended
Sensor Interface Front-Ends
The PIC16C505-04/SL serves as a low-cost digital front-end that reads digital sensors and transmits results via bit-banged serial protocols (UART, SPI, I2C slave). With 12 I/O pins, the device can handle multiple sensor inputs, status LEDs, and a single serial output simultaneously. The 4 MHz instruction cycle provides sufficient throughput to debounce mechanical switches, time-window sample inputs, and format serial frames without overrun. OTP memory makes the firmware immutable for safety-critical sensor modules.
Recommended
Smart Home Edge Nodes
Discrete IoT edge nodes such as smart switches, plug-in relay modules, or simple door/window sensor transmitters benefit from the PIC16C505-04/SL's compact 14-pin SOIC footprint and low component count. The MCU wakes up on a digital interrupt, reads the sensor state, transmits via a companion RF IC over a bit-banged SPI/UART, and returns to sleep. Code-locked OTP memory secures the device identity in deployed smart-home installations where unauthorized firmware replacement is a security concern.
Recommended
Recommended Products Summary
Engineering reference data for PIC16C505-04/SL β comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16C505-04I/SL | PIC16C505-04E/SL | PIC16C505-20/SL | PIC16C505-20I/SL | PIC16F505-I/SL |
|---|---|---|---|---|---|---|
| Package | 14-pin SOIC (SL) | 14-pin SOIC (SL) - same | 14-pin SOIC (SL) - same | 14-pin SOIC (SL) - same | 14-pin SOIC (SL) - same | 14-pin SOIC (SL) - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Maximum Clock Frequency | 4 MHz | 4 MHz | 4 MHz | 20 MHz | 20 MHz | 20 MHz |
| Program Memory Type | OTP (1.5 KB / 1K x 12) | OTP (1.5 KB / 1K x 12) | OTP (1.5 KB / 1K x 12) | OTP (1.5 KB / 1K x 12) | OTP (1.5 KB / 1K x 12) | Flash (1.5 KB / 1K x 12) |
| Data RAM | 72 bytes | 72 bytes | 72 bytes | 72 bytes | 72 bytes | 72 bytes |
| Digital I/O Pins | 12 | 12 | 12 | 12 | 12 | 12 |
| Temperature Grade | Commercial (0C to +70C) | Industrial (-40C to +85C) | Extended (-40C to +125C) | Commercial (0C to +70C) | Industrial (-40C to +85C) | Industrial (-40C to +85C) |
| Watchdog Timer | Yes (dedicated RC osc) | Yes (dedicated RC osc) | Yes (dedicated RC osc) | Yes (dedicated RC osc) | Yes (dedicated RC osc) | Yes (dedicated RC osc) |
| ICSP Programming | Yes | Yes | Yes | Yes | Yes | Yes (flash allows in-system reprogram) |
Key Differentiators
- Industrial temperature grade drop-in (vs PIC16C505-04I/SL)
- Higher speed grade option (vs PIC16C505-20/SL)
- Flash-based alternative for development (vs PIC16F505-I/SL)
Design Notes
The PIC16C505-04/SL operates across a wide voltage range but lacks an internal brown-out reset on older silicon revisions; design with an external voltage supervisor IC (e.g., MCP100 or MCP809) on the /MCLR line for fail-safe operation in battery or industrial environments where VDD can droop below safe thresholds during motor or relay switching events. Use a 100 nF decoupling capacitor within 5 mm of the VDD pin and a bulk 10 uF tantalum or ceramic on the supply rail.
OTP (one-time programmable) memory cannot be re-programmed or erased. Engineers must burn a working code image with no remaining bugs; for development, prototype with the flash-based PIC16F505-I/SL (same 14-pin SOIC, same PIC16 core), then migrate to PIC16C505-04/SL only after firmware is fully validated. Programming must use Microchip's ICSP protocol with VPP applied to /MCLR; applying 12V to a non-ICSP-capable pin will damage the device.
Keep the clock oscillator traces short (less than 5 mm from OSC1/OSC2 to the crystal or resonator). For RC oscillator mode (lowest cost), place the timing resistor and capacitor adjacent to OSC1 with the capacitor ground return going directly to the VSS pin. Route high-current switching signals (relay coils, LED strings) away from the clock traces and use a ground-plane stitch of vias around the SOIC to minimize radiated EMI into the oscillator circuit.
The 12 I/O pins share a common ground reference; when driving inductive loads (relays, solenoids), add flyback diodes directly across each coil and separate the relay-supply ground return from the digital ground. For sensor inputs more than 50 mm from the MCU, add a 100 nF bypass capacitor and a 1-10 kohm series resistor at the input pin to suppress ringing and ESD. Avoid long parallel traces between I/O and the clock pins to prevent capacitive coupling.
Compliance Information
Compliance status for RoHS, REACH, lead-free, halogen-free not stated in the provided distributor or datasheet excerpts; Microchip product page should be consulted for authoritative compliance data.
