PIC16C505-04/P - 8-Bit 4MHz OTP MCU, 1.5KB, 12 I/O | Microchip
MPN: PIC16C505-04/P โ End of Life| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $3.61 | $3.61 |
| 10 | $3.25 | $32.50 |
| 100 | $2.78 | $278.00 |
| 500 | $2.41 | $1,205.00 |
| 1,000 | $2.05 | $2,050.00 |
PIC16C505-04/P Overview
A microcontroller (MCU) is a single-chip computer that combines a CPU core, program memory, data RAM, and programmable I/O peripherals. Within the broader taxonomy, the PIC16C505 sits in the 8-bit RISC MCU class, descended from the original PICยฎ (Peripheral Interface Controller) architecture introduced by General Instruments and commercialized by Microchip. It belongs to the enhanced PIC16 mid-range family, which uses a Harvard architecture with separate program and data buses and a small RISC instruction set optimized for deterministic real-time control. PIC16C-series parts are OTP (One-Time-Programmable) EPROM-based, distinguishing them from the Flash-based PIC16F series.
The device features a 12-bit instruction word, 33 single-word/single-cycle instructions, a hardware 8-bit timer/counter (TMR0) with an 8-bit prescaler, watchdog timer with its own on-chip RC oscillator, programmable code protection, power-on reset, power-saving SLEEP mode, and a 4 MHz internal/external clock input option. The '04' speed grade specifies a 4 MHz maximum oscillator input.
Architecturally, the PIC16C505 uses an 8-level deep hardware stack, two I/O ports (PORTB 8 bits and PORTC limited), and an internal RC oscillator that reduces external component count. The 14-pin PDIP package provides 12 usable I/O pins after dedicating one pin to VDD, one to VSS, and one to MCLR/VPP.
Typical applications include low-cost consumer appliance control, sensor signal conditioning, LED driving and lighting controllers, battery chargers, small home appliances, automotive body electronics subsystems, and replacement of discrete logic ICs in legacy designs. Its small footprint, low price, and ease of programming (33-instruction set) make it a frequent choice for simple state-machine and timing-control tasks.
Designers should note that the OTP variant cannot be reprogrammed in-circuit; engineering samples should use the PIC16F505 flash equivalent for iterative development. Code-protect bits should be verified before final production programming to prevent unauthorized memory reads.
This page synthesizes distributor pricing, pin-compatible alternatives, and practical design guidance drawn from the PIC16C505 datasheet and reference manuals.
Drop-in alternatives for PIC16C505-04/P โ 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/P (same form factor and footprint) โ differing in Core Architecture, Instruction Cycle Time, Mounting Type, Package, Program Memory Size.
Quick Comparison Tool โ Select alternative parts for side-by-side comparison:
PIC16F505-I/P
โ Drop-In๐ Reference alternative (not in catalog)
PIC16F505T-I/SN
โ Drop-In โ ๏ธ ๅๆฐๅพ ้ช่ฏ๐ Reference alternative (not in catalog)
PIC16C505-20/P
โ Drop-In๐ Reference alternative (not in catalog)
PIC16C505-04/SO
โ Drop-In โ ๏ธ ๅๆฐๅพ ้ช่ฏ๐ Reference alternative (not in catalog)
PIC16C54A-04/P
โ Drop-Inโ In Stock
$3.75 / Unit
View Datasheet โPIC16C505-04/P Maximum Ratings & Electrical Characteristics
| Product Type | 8-Bit Microcontroller (MCU) |
| Core Architecture | PIC16 (RISC, Harvard) |
| Instruction Set Width | 12-bit |
| Number of Instructions | 33 single-word/single-cycle |
| Maximum Clock Frequency | 4 MHz |
| Instruction Cycle Time | 200 ns |
| Program Memory Type | OTP EPROM |
| Program Memory Size | 1.5 KB (1K x 12) |
| Data RAM | 72 bytes |
| I/O Pins | 12 |
| Timers | 1 x 8-bit (TMR0 with 8-bit prescaler) |
| Watchdog Timer | Yes (with dedicated on-chip RC oscillator) |
| Package | 14-pin PDIP (P) |
| Mounting Type | Through-Hole |
| Special Features | Power-on reset, SLEEP mode, code protection, internal RC oscillator option |
PIC16C505-04/P Pin Configuration
| Pin 1 | RA2 โ Bidirectional I/O port A bit 2 |
| Pin 2 | RA3 โ Bidirectional I/O port A bit 3 |
| Pin 3 | RA4/T0CKI โ Bidirectional I/O port A bit 4 / Timer0 clock input |
| Pin 4 | MCLR/VPP โ Master Clear (reset) input / Programming voltage input |
| Pin 5 | VSS โ Ground reference |
| Pin 6 | RC0 โ Bidirectional I/O port C bit 0 |
| Pin 7 | RC1 โ Bidirectional I/O port C bit 1 |
| Pin 8 | RC2 โ Bidirectional I/O port C bit 2 |
| Pin 9 | RC3 โ Bidirectional I/O port C bit 3 |
| Pin 10 | RC4 โ Bidirectional I/O port C bit 4 |
| Pin 11 | RC5 โ Bidirectional I/O port C bit 5 |
| Pin 12 | RB0/INT โ Bidirectional I/O port B bit 0 / External interrupt input |
| Pin 13 | RB1 โ Bidirectional I/O port B bit 1 |
| Pin 14 | VDD โ Positive supply voltage |
Typical Applications
PIC16C505-04/P is suitable for 6 applications: Consumer Appliance Control, Sensor Signal Conditioning, LED Driving and Lighting Control, Battery Chargers, Automotive Body Electronics, Discrete Logic Replacement.
Consumer Appliance Control
The PIC16C505-04/P's 12 I/O, 4 MHz operation, and 33-instruction RISC core fit low-cost consumer appliance controllers such as toaster ovens, coffee makers, washing-machine sub-modules, and microwave keypads. Its OTP memory prevents firmware extraction for anti-clone protection, and the 14-pin PDIP through-hole package simplifies wave-solder assembly on traditional single-layer appliance PCBs. The integrated watchdog timer and POR improve field reliability against brown-out events common in appliance power environments. With 72 bytes RAM and 1.5 KB program memory, the device handles 8-12 state-machine tasks comfortably.
Recommended
Sensor Signal Conditioning
For analog sensor interfaces with simple threshold logic, the PIC16C505-04/P reads digital sensor outputs via its 12 I/O pins and applies debouncing, hysteresis, and calibration algorithms in firmware. Its 200 ns instruction cycle enables microsecond-resolution timing for pulse-width measurement on Hall-effect, optical, and capacitive sensors. The TMR0 timer with 8-bit prescaler provides up to 51.2 microsecond resolution at 4 MHz, sufficient for RPM, flow-rate, and proximity detection. The internal RC oscillator option reduces BOM cost by eliminating external crystals in cost-sensitive applications.
Recommended
LED Driving and Lighting Control
The PIC16C505-04/P is well suited for low-channel-count LED driving applications such as decorative lighting, status indicators, RGB color-mixing controllers, and small signage. Each of its 12 I/O pins can source/sink up to 25 mA directly, enabling direct drive of indicator LEDs without external transistors. Software PWM at 4 MHz easily generates 8-bit resolution at refresh rates above 100 Hz, eliminating visible flicker. The SLEEP mode with watchdog wake-up supports battery-powered nightlights and ambient lighting with multi-year coin-cell life.
Recommended
Battery Chargers
Simple NiCd, NiMH, and lead-acid charger controllers use the PIC16C505-04/P's timer, ADC-free comparator inputs, and PWM-like bit-banging to regulate charge current and termination voltage. The OTP memory stores calibrated charge profiles permanently, preventing field firmware drift. The 4 MHz clock provides ample resolution for delta-V peak charge termination algorithms on NiMH cells. Integrated watchdog and POR ensure recovery from transient brown-outs common in automotive and power-tool battery applications.
Recommended
Automotive Body Electronics
In automotive body modules such as window lift switches, mirror controllers, seat adjusters, and interior lighting, the PIC16C505-04/P provides deterministic real-time control. The '04' grade operates across automotive temperature ranges with proper derating. Note that the PIC16C505 is NRND - new automotive designs should specify the PIC16F505-I/P (Flash) or PIC16F505-E/P (extended temperature) variants with AEC-Q100 qualification. Existing designs with validated OTP firmware can continue production sourcing.
Recommended
Discrete Logic Replacement
Engineers frequently replace multi-chip 74xx discrete logic gate arrays with a single PIC16C505-04/P to reduce board area, BOM count, and inventory SKU complexity. The MCU implements AND/OR/XOR/state-machine functions in firmware, eliminating propagation-delay skew between gates and improving EMC. Its 12 I/O can replace up to 6 SOP-14 logic packages. The OTP memory guarantees fixed behavior, simplifying UL/CE safety certification compared to firmware-updatable alternatives.
Recommended
Recommended Products Summary
Engineering reference data for PIC16C505-04/P โ comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16F505-I/P | PIC16C505-20/P | PIC16C54A-04/P | PIC12F629-I/P | PIC12F675-I/P |
|---|---|---|---|---|---|---|
| Package | 14-pin PDIP | 14-pin PDIP (drop-in) | 14-pin PDIP (drop-in) | 14-pin PDIP (drop-in) | 8-pin PDIP (different footprint) | 8-pin PDIP (different footprint) |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Program Memory | 1.5 KB OTP | 1.5 KB Flash | 1.5 KB OTP (same) | 768 B OTP (-49%) | 1.75 KB Flash (+17%) | 1.75 KB Flash (+17%) |
| Max Clock Frequency | 4 MHz | 20 MHz (+400%) | 20 MHz (+400%) | 4 MHz (same) | 20 MHz (+400%) | 20 MHz (+400%) |
| RAM | 72 bytes | 72 bytes (same) | 72 bytes (same) | 25 bytes (-65%) | 64 bytes (-11%) | 64 bytes (-11%) |
| I/O Pins | 12 | 12 (same) | 12 (same) | 12 (same) | 6 (-50%) | 6 (-50%) |
| Memory Type | OTP EPROM | Flash (reprogrammable) | OTP EPROM (same) | OTP EPROM (same) | Flash (reprogrammable) | Flash (reprogrammable) |
| Lifecycle Status | NRND | Active | NRND | NRND/EOL | Active | Active |
| ADC | None | None | None | None | None | 10-bit ADC |
Key Differentiators
- Drop-in Flash replacement with 5x faster clock (vs PIC16F505-I/P)
- Higher speed grade available in same package (vs PIC16C505-20/P)
- Legacy PIC16C54A compatibility with more RAM (vs PIC16C54A-04/P)
Design Notes
Decouple VDD (pin 14) with a 100 nF ceramic capacitor placed within 5 mm of the MCU, plus a 10 uF bulk capacitor on the board's power entry. The PIC16C505-04/P has no internal POR delay beyond a fixed filter; an external RC delay on MCLR (pin 4) may be required for slow-rising supplies. Expected: at 4 MHz active and 5V supply, core current is approximately 1.8 mA typical, dropping to low microampere levels in SLEEP mode (verify exact Iq from electrical characteristics table for your Vdd setting).
Place the decoupling capacitor directly between pin 14 (VDD) and pin 5 (VSS) with the shortest possible trace length - this minimises switching noise injection during I/O transitions. If using an external crystal or resonator (instead of the internal RC oscillator), keep the oscillator traces short and surrounded by a ground pour to prevent EMI radiation. MCLR trace should also be short and may include a 10 kohm pull-up to VDD for proper reset behaviour.
Critical: OTP EPROM cannot be erased. Once programmed, the PIC16C505-04/P cannot be re-flashed, so engineering prototypes should use the PIC16F505-I/P (Flash equivalent) until firmware is finalised. Watchdog timer must be explicitly disabled in configuration bits if not used, otherwise unexpected resets will occur. Configuration word (address 0x0FFF) must be set before code protection bits, otherwise the device becomes unreadable for verification. Estimated: programming time per device via high-voltage ICSP is approximately 3-5 seconds including verification.
Compliance Information
Compliance flags not present in verified web data; consult Microchip PIC16C505 product page for current RoHS/REACH declarations. The '04' commercial speed grade is not AEC-Q100 qualified; for automotive designs use the PIC16F505-E/P (extended temperature) or AEC-Q100 qualified variants.
