PIC16C505/JW - 8-Bit 20MHz EPROM MCU 1.5KB | Microchip
MPN: PIC16C505/JW β Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $7.5 | $7.50 |
| 10 | $6.75 | $67.50 |
| 100 | $6 | $600.00 |
| 500 | $5.4 | $2,700.00 |
| 1,000 | $4.85 | $4,850.00 |
PIC16C505/JW Overview
A microcontroller is a single-chip computer that integrates a CPU, memory, and programmable I/O peripherals. The PIC16C505 belongs to the PIC (Peripheral Interface Controller) family, specifically the PIC16 sub-family, which sits within the broader 8-bit RISC microcontroller category and the embedded-system semiconductor hierarchy. Its 12-bit-wide instruction word and Harvard architecture deliver ~2:1 code compression versus typical 8-bit CISC competitors, allowing compact firmware in small program-memory footprints.
Key features of the PIC16C505/JW include: 33 single-word/single-cycle instructions, an integrated 4 MHz internal RC oscillator (with external oscillator support up to 20 MHz), 12 I/O pins, a watchdog timer with on-chip RC oscillator, power-on reset, power-saving Sleep mode, and 8-bit timer/counter with prescaler. The /JW suffix denotes a ceramic DIP package with an erasure window, supporting UV-erase for iterative firmware development rather than the plastic OTP variants.
The device uses CMOS EPROM-based memory (windowed for erasure), a 12-bit instruction word, and an 8-bit data path. Its wide operating voltage (2.5V-5.5V) and low power consumption allow battery-backed or unregulated-supply designs. The EPROM-based UV-erasable memory cell supports hundreds of erase/write cycles, making it well-suited to engineering development where firmware is repeatedly revised.
Typical applications include industrial control logic, sensor signal conditioning, low-cost consumer appliances, hobby/educational microcontroller platforms, prototyping replacements for masked-ROM devices, and any design that benefits from a 14-pin through-hole windowed MCU for in-house reprogramming. The /JW package specifically enables UV erasure so the same silicon can be reused across firmware revisions.
When designing with this device, ensure the UV-erase window remains covered with opaque tape during normal operation to prevent accidental data loss from ambient light. Note that the JW windowed package is intended primarily for development; production builds typically migrate to PIC16F505 (Flash) or PIC16C505-OTP variants for lower cost and no erasure-window handling.
This page synthesizes distributor pricing, parametric alternatives, and practical design notes not found in the manufacturer datasheet.
Drop-in alternatives for PIC16C505/JW β same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Quick Comparison Tool β Select alternative parts for side-by-side comparison:
PIC16C505-20I/JW
β Drop-Inπ Reference alternative (not in catalog)
PIC16C505-04I/JW
β Drop-Inπ Reference alternative (not in catalog)
PIC16C505-20/JW
β Drop-Inπ Reference alternative (not in catalog)
PIC16C505-04/JW
β Drop-Inπ Reference alternative (not in catalog)
PIC16C505-10/JW
β Drop-Inπ Reference alternative (not in catalog)
PIC16C505/JW Maximum Ratings & Electrical Characteristics
| Core | PIC 8-bit RISC |
| Instruction Set Width | 12-bit |
| Number of Instructions | 33 (single-word, single-cycle) |
| Program Memory Type | EPROM (UV-erasable, windowed) |
| Program Memory Size | 1.5 KB (1K x 12) |
| RAM | 72 bytes |
| Maximum CPU Speed | 20 MHz (200 ns instruction cycle) |
| Operating Voltage Range | 2.5 V to 5.5 V |
| I/O Pins | 12 |
| Timers | 1 x 8-bit with prescaler |
| Watchdog Timer | Yes (with on-chip RC oscillator) |
| Internal Oscillator | Yes (4 MHz RC) |
| Package | 14-pin CDIP (Ceramic DIP with window) |
| Mounting Type | Through-Hole |
PIC16C505/JW Pin Configuration
| Pin 1 | VDD β Positive supply voltage (2.5V-5.5V) |
| Pin 2 | OSC1/CLKIN β Oscillator input / external clock input |
| Pin 3 | OSC2/CLKOUT β Oscillator output / 4x clock output |
| Pin 4 | MCLR/VPP β Master clear (reset) / programming voltage input |
| Pin 5 | VSS β Ground reference |
| Pin 6 | GP0 β Bidirectional I/O pin 0 / ICSPDAT |
| Pin 7 | GP1 β Bidirectional I/O pin 1 / ICSPCLK |
| Pin 8 | GP2 β Bidirectional I/O pin 2 / T0CKI timer0 clock input |
| Pin 9 | GP3 β Input-only pin 3 / MCLR alt / VPP alt |
| Pin 10 | GP4 β Bidirectional I/O pin 4 |
| Pin 11 | GP5 β Bidirectional I/O pin 5 |
| Pin 12 | GP6 β Bidirectional I/O pin 6 |
| Pin 13 | GP7 β Bidirectional I/O pin 7 |
| Pin 14 | VSS β Ground reference (or duplicate VSS - [DATA_NEEDED: confirm dual VSS assignment]) |
Typical Applications
PIC16C505/JW is suitable for 6 applications: Industrial Control Logic, Sensor Signal Conditioning, Low-Cost Consumer Appliances, Hobby and Educational Microcontroller Platforms, Prototyping Replacement for Masked-ROM Devices, Field-Reprogrammable Embedded Modules.
Industrial Control Logic
The PIC16C505/JW fits industrial control logic where deterministic 8-bit RISC performance is required in a cost-sensitive, through-hole footprint. Its 33 single-cycle instructions and 20 MHz / 200 ns execution allow real-time handling of discrete I/O such as relay drivers, valve control, and sequencing of conveyor or pump actuators. The 12 I/O pins can directly drive logic-level interfaces or low-side MOSFETs for higher-current loads. The wide 2.5V-5.5V supply range tolerates slightly unregulated industrial 24V->5V rails after a simple linear regulator, and the integrated watchdog timer with on-chip RC oscillator improves fault recovery in unattended machinery. Because the /JW variant uses a windowed ceramic package, design teams can iterate firmware over many UV-erase cycles during product qualification without scrapping silicon.
Recommended
Sensor Signal Conditioning
In sensor signal conditioning front-ends, the PIC16C505/JW provides the timing, calibration, and digital I/O required to drive resistive bridges, thermistors, and simple 4-20 mA loops. Its 12-bit instruction width and Harvard architecture allow compact, deterministic firmware for linearization, averaging, and threshold detection in noisy industrial environments. The integrated 4 MHz RC oscillator simplifies BOM by removing external crystals in non-timing-critical channels, while the option of an external 20 MHz crystal supports higher sampling rates when needed. With 1.5KB of EPROM and 72 bytes of RAM, the device can store calibration constants and run small state machines that drive FETs or relays based on measured thresholds. The windowed /JW package enables iterative refinement of calibration firmware during sensor characterization.
Recommended
Low-Cost Consumer Appliances
The PIC16C505/JW suits low-cost consumer appliances such as small kitchen devices, personal care products, and simple household gadgets where a microcontroller replaces discrete logic for user-interface and timing functions. Its 8-bit RISC core, 33 single-cycle instructions, and 1.5KB EPROM deliver enough headroom for blinking patterns, button debouncing, motor PWM, and timer-driven sequences while keeping unit cost low. The 14-pin DIP footprint simplifies hand-soldered prototypes and short production runs. The 2.5V-5.5V operating range enables single-cell Li-ion (with boost) or 3xAA battery-powered designs, and the integrated watchdog timer improves robustness against brown-outs. Engineering teams can use the /JW windowed package to develop and refine firmware across many UV-erase cycles, then transition to a plastic OTP part for mass production.
Recommended
Hobby and Educational Microcontroller Platforms
The PIC16C505/JW is well-suited for hobbyist and educational microcontroller platforms because the UV-erasable /JW windowed package allows the same chip to be reprogrammed dozens to hundreds of times, perfect for learning assembler, experimenting with peripheral code, and teaching RISC concepts. Its 33 single-word instructions, 12-bit instruction width, and 8-bit data path are simple enough to teach computer-architecture fundamentals yet still useful for real projects. The 14-pin DIP footprint is breadboard-friendly, making it easy for students and hobbyists to wire LED arrays, push buttons, and sensor breakouts. With 1.5KB of EPROM and 72 bytes of RAM, beginners can write meaningful programs for blinking, PWM, and basic state machines. The integrated watchdog and brown-out reset teach good embedded practices from day one.
Recommended
Prototyping Replacement for Masked-ROM Devices
The PIC16C505/JW is the prototyping workhorse for designs that will eventually migrate to lower-cost masked-ROM PIC16C505 variants once firmware is finalized. Engineers use the /JW windowed ceramic package to validate firmware on the exact silicon die, then transition the same firmware to masked-ROM production parts to reduce per-unit cost. This avoids the risk of migrating to a different part number late in development, because the prototype and production silicon share the same core architecture, peripheral set, and electrical characteristics. The 1.5KB program memory and 72 bytes of RAM allow meaningful pre-production code, and the 2.5V-5.5V supply range lets engineers qualify the design against all production voltage conditions. The /JW package supports repeated UV erase cycles for firmware refinement without scrapping silicon.
Recommended
Field-Reprogrammable Embedded Modules
For field-reprogrammable embedded modules where code iteration is expected over the product life, the PIC16C505/JW offers a UV-erasable EPROM-based MCU that can be removed, erased under a UV lamp, and reprogrammed. This is useful in long-lifecycle industrial installations, military prototypes, and legacy equipment retrofits where Flash tooling is not available or EPROM-based toolchains are required for certification reasons. The 20 MHz instruction execution, 12 I/O pins, and 1.5KB program memory support modest real-time control tasks, while the 14-pin ceramic DIP provides mechanical ruggedness. Designers can integrate the /JW part into modules shipped with a UV-erase cover, allowing service technicians to refresh firmware without replacing the silicon. The wide 2.5V-5.5V operating range also tolerates field-supply variability.
Recommended
Recommended Products Summary
Engineering reference data for PIC16C505/JW β comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16C505-20I/JW | PIC16C505-04I/JW | PIC16C505-20/JW | PIC16C505-04/JW | PIC16C505-10/JW |
|---|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 14-CDIP (windowed) | 14-CDIP (windowed) - same | 14-CDIP (windowed) - same | 14-CDIP (windowed) - same | 14-CDIP (windowed) - same | 14-CDIP (windowed) - same |
| Program Memory Type | UV-EPROM (1.5 KB / 1K x 12) | UV-EPROM (1.5 KB) | UV-EPROM (1.5 KB) | UV-EPROM (1.5 KB) | UV-EPROM (1.5 KB) | UV-EPROM (1.5 KB) |
| RAM | 72 bytes | 72 bytes | 72 bytes | 72 bytes | 72 bytes | 72 bytes |
| Maximum CPU Speed | 20 MHz | 20 MHz | 4 MHz | 20 MHz | 4 MHz | 10 MHz |
| Operating Voltage | 2.5V to 5.5V | 2.5V to 5.5V | 2.5V to 5.5V | 2.5V to 5.5V | 2.5V to 5.5V | 2.5V to 5.5V |
| I/O Pins | 12 | 12 | 12 | 12 | 12 | 12 |
| Instruction Set | 33 single-cycle (12-bit) | 33 single-cycle (12-bit) | 33 single-cycle (12-bit) | 33 single-cycle (12-bit) | 33 single-cycle (12-bit) | 33 single-cycle (12-bit) |
Key Differentiators
- UV-erasable windowed ceramic package supports hundreds of erase/reprogram cycles (vs PIC16F505-I/P)
- Single 14-CDIP windowed family covers 4-20 MHz speed grades (vs PIC16C505-04/JW)
- Internal 4 MHz RC oscillator eliminates external crystal for cost-sensitive designs (vs PIC16F505-I/P)
Design Notes
The PIC16C505/JW UV-erasable window must remain covered with opaque tape during normal operation. Ambient sunlight or fluorescent light can erase EPROM contents over hours to days, leading to firmware loss. Use only opaque electrical tape rated for the operating temperature range. For development, erase with a calibrated UV lamp rated for EPROM erasure (typically 254 nm wavelength, ~20 minutes at recommended intensity per the datasheet). Avoid touching the quartz window, which can leave residue that blocks UV light during erasure.
Place a 100 nF decoupling capacitor as close as possible to the VDD pin (pin 1) and a bulk capacitor of at least 10 uF on the same supply trace. The MCLR/VPP pin (pin 4) should be pulled to VDD through a 10 kohm resistor and have a decoupling capacitor (~100 nF) to ground if high-voltage ICSP programming is used. Keep the oscillator traces short, and if using a crystal, place the load capacitors within 5 mm of OSC1 and OSC2 to minimize stray capacitance that could shift the oscillation frequency.
Configuration bits (fuses) for the PIC16C505 must be set correctly to avoid unexpected behavior. Common pitfalls include disabling the watchdog timer unintentionally, leaving the oscillator in an unsupported mode, or enabling code protection on a windowed part (which prevents UV erasure). Always review the __CONFIG register value against the datasheet configuration-word table before programming. Use the Microchip MPLAB X IDE configuration-bit dialog to set oscillator, watchdog, code-protection, and brown-out-reset options safely.
When using GP3 as an input-only pin (per the datasheet), do not drive it as an output. Configure the TRIS register bit appropriately and avoid external pull-up conflicts. The ICSP pins (GP0/GP1) share GP functions; if a peripheral on those pins is critical, isolate them from the ICSP header using jumpers or a separate programming connector to avoid loading during in-circuit programming. Add ESD protection diodes (e.g., PESD5V0L4UG) on external I/O if the device is exposed to user touch or harsh environments.
Compliance Information
RoHS/lead-free status of the ceramic CDIP /JW package is not stated in the verified web data; Microchip documentation should be consulted for current compliance certifications.
