PIC16C56/JW - 8-bit 20MHz 1.5KB EPROM MCU | Microchip | CERDIP-18
MPN: PIC16C56/JW β Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $12.5 | $12.50 |
| 10 | $11.25 | $112.50 |
| 100 | $9.8 | $980.00 |
| 500 | $8.65 | $4,325.00 |
| 1,000 | $7.4 | $7,400.00 |
PIC16C56/JW Overview
Key features include 25 bytes of RAM, 12 I/O pins, 8-bit timer/counter (TMR0), two-level hardware stack, 33 single-word/single-cycle instructions, and a wide operating voltage range that supports both 3.3 V and 5 V rails. The JW suffix denotes a windowed CERDIP package, allowing the EPROM to be erased with ultraviolet light and reprogrammed, which makes this part suitable for engineering development and prototyping rather than high-volume production.
The PIC16C5X architecture is one of the original PIC microcontroller families, employing a Harvard-style RISC design with separate program and data buses, 12-bit wide instructions, and 8-bit wide data path. The device is fully static, allowing the clock to be stopped without losing internal state. This architecture predates the later PIC16F and PIC18 families but remains popular in legacy industrial controls, automotive subsystems, and education markets where long lifecycle support and known behavior are valued.
Typical applications include simple logic replacement, motor and relay control, sensor signal conditioning, LED and seven-segment display driving, and battery-powered instruments. The low part count (no external program memory or data memory required) and inexpensive ceramic package make the PIC16C56/JW a fit for prototypes and small retrofit projects.
When designing with this part, note that the windowed CERDIP package is significantly more expensive than the equivalent OTP plastic DIP variant (PIC16C56-04/P or PIC16C56-20/P). Reserve the JW version for development cycles where code revision is anticipated. Per the Microchip datasheet, all unused I/O pins should be configured as outputs to minimize current consumption.
This page synthesizes distributor pricing, drop-in same-family alternatives, and practical development notes not found in the manufacturer datasheet.
Drop-in alternatives for PIC16C56/JW 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 PIC16C56/JW (same form factor and footprint) β differing in Core Architecture, I/O Pins, Program Memory Size, Program Memory Type, Operating Temperature.
Quick Comparison Tool β Select alternative parts for side-by-side comparison:
PIC16C55/JW
β Drop-Inβ In Stock
$10.4 / Unit
View Datasheet βPIC16C558/JW
β Drop-Inβ In Stock
$4.85 / Unit
View Datasheet βPIC16C554/JW
β Drop-Inβ In Stock
$4.69 / Unit
View Datasheet βPIC16C56-04/P
β Drop-Inπ Reference alternative (not in catalog)
PIC16C56-20/P
β Drop-Inπ Reference alternative (not in catalog)
PIC16C56/JW Maximum Ratings & Electrical Characteristics
| Core Architecture | PIC 8-bit RISC |
| Program Memory Type | EPROM (UV-erasable, windowed) |
| Program Memory Size | 1.5 KB (1K x 12) |
| RAM Size | 25 bytes |
| Maximum CPU Speed | 20 MHz |
| I/O Pins | 12 |
| Timers | 1 x 8-bit (TMR0) |
| Instruction Set | 33 single-word instructions |
| Stack Depth | 2 levels (hardware) |
| Operating Voltage | 2.5 V to 6.25 V (3.3 V / 5 V typical) |
| Package Type | 18-pin CERDIP with quartz window (JW) |
| Through-Hole Pitch | 2.54 mm (0.100 in) |
| Mounting Type | Through-Hole |
| Operating Temperature | 0C to +70C (commercial) |
| RoHS Status | Compliant (Pb-free ceramic) |
| Data EEPROM | None |
PIC16C56/JW Pin Configuration
| Pin 1 | MCLR/VPP β Master clear reset (active low) / programming voltage input |
| Pin 2 | RA0 β Bidirectional I/O port A bit 0 |
| Pin 3 | RA1 β Bidirectional I/O port A bit 1 |
| Pin 4 | RB0 β Bidirectional I/O port B bit 0 / external interrupt |
| Pin 5 | RB1 β Bidirectional I/O port B bit 1 |
| Pin 6 | RB2 β Bidirectional I/O port B bit 2 |
| Pin 7 | RB3 β Bidirectional I/O port B bit 3 |
| Pin 8 | RB4 β Bidirectional I/O port B bit 4 |
| Pin 9 | RB5 β Bidirectional I/O port B bit 5 |
| Pin 10 | GND β Ground reference |
| Pin 11 | RB6 β Bidirectional I/O port B bit 6 |
| Pin 12 | RB7 β Bidirectional I/O port B bit 7 |
| Pin 13 | RC0 β Bidirectional I/O port C bit 0 |
| Pin 14 | RC1 β Bidirectional I/O port C bit 1 |
| Pin 15 | RC2 β Bidirectional I/O port C bit 2 |
| Pin 16 | RC3 β Bidirectional I/O port C bit 3 |
| Pin 17 | RC4 β Bidirectional I/O port C bit 4 / TMR0 clock input |
| Pin 18 | OSC1/CLKIN β Oscillator crystal input / external clock input |
Typical Applications
PIC16C56/JW is suitable for 6 applications: Legacy Industrial Control Retrofit, Automotive Accessory Controllers, Educational Microcontroller Training, Sensor Signal Conditioning Hubs, Battery-Powered Remote Sensor Nodes, Hobby Electronics and Maker Projects.
Legacy Industrial Control Retrofit
The PIC16C56/JW is well suited to replacing obsolete 8-bit controllers in legacy industrial equipment where redesign costs would exceed the value of the upgrade. Its 1.5 KB of EPROM handles typical PLC-style ladder-logic replacement and small sensor-fusion tasks, while the 20 MHz clock provides sufficient throughput for 10 ms scan loops. The windowed CERDIP package lets field engineers revise firmware on-site using a standard UV eraser and programmer, eliminating board rework. With 12 I/O pins, the part can directly interface 24 V opto-isolated inputs and relay outputs through external drivers, and the 2.5-6.25 V supply range tolerates noisy industrial backplanes without additional regulation.
Recommended
Automotive Accessory Controllers
Inside aftermarket automotive accessories such as alarm modules, central-locking controllers, and lighting sequencers, the PIC16C56/JW provides reliable 8-bit control with proven long-term Microchip supply. The 1.5 KB EPROM holds typical accessory logic plus state-machine sequencing, and the 25-byte RAM is adequate for temporary flags and timer variables. The 20 MHz clock supports PWM dimming and debounce routines for mechanical switches. The 18-pin CERDIP package withstands under-hood temperature swings when conformal coating is applied, and the wide 2.5-6.25 V supply tolerates automotive load-dump transients after external TVS protection.
Recommended
Educational Microcontroller Training
The PIC16C56/JW is a standard teaching vehicle in university embedded-systems courses because its 33-instruction RISC core can be mastered in a single lab session, yet it is powerful enough for senior-project work. The windowed JW package allows students to erase and re-flash their code dozens of times per semester, dramatically reducing per-student consumable cost. The 18-pin DIP form factor fits standard breadboards and 0.100 in pitch perfboards used in teaching labs. With a 20 MHz clock and 1.5 KB EPROM, the part supports final projects involving serial communication, ADC read via external chip, and stepper-motor control.
Recommended
Sensor Signal Conditioning Hubs
For distributed sensor networks where a low-cost 8-bit controller performs first-stage filtering and threshold detection, the PIC16C56/JW offers the right balance of capability and cost. The 8-bit TMR0 timer with 1:2 to 1:256 prescaler handles precise sample-rate generation for thermocouple or RTD front-ends, and 12 I/O pins interface multiplexed analog switches and 1-Wire or I2C sensors via bit-banging. The 1.5 KB EPROM supports moving-average and simple Kalman filter implementations, while the wide supply range accepts direct 3.3 V or 5 V transducer power.
Recommended
Battery-Powered Remote Sensor Nodes
In remote or wireless sensor nodes where quiescent current dominates battery life, the PIC16C56/JW's CMOS EPROM process and ability to halt the clock while keeping state allow deep sleep modes below 1 uA typical. The 2.5 V minimum supply voltage enables direct Li-coin-cell operation, and the 25-byte RAM retains wake-up flags and counters during sleep. The 20 MHz wake-up time is short enough for periodic temperature, humidity, or motion-logging applications. The windowed CERDIP is used in development; production builds migrate to the PIC16C56-20/P or PIC16F57 for lower cost.
Recommended
Hobby Electronics and Maker Projects
The PIC16C56/JW remains popular among hobbyists who build PIC-based chiptune synthesizers, retro gaming controllers, model railroad controllers, and animatronic puppet drivers. The windowed package lets makers iterate on firmware without scrapping chips, and the 18-pin DIP through-hole form factor is friendly to point-to-point wiring and stripboard prototyping. The 1.5 KB EPROM holds small lookup tables for sound generation or PWM sequences, and 20 MHz provides enough headroom for software UART emulation. With 12 I/O, makers can directly drive servos, LEDs, and H-bridges.
Recommended
Recommended Products Summary
Engineering reference data for PIC16C56/JW β comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16C55/JW | PIC16C558/JW | PIC16C554/JW | PIC16C56-04/P | PIC16C56-20/P |
|---|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 18-CERDIP (JW, windowed) | 18-CERDIP (JW, windowed) | 18-CERDIP (JW, windowed) | 18-CERDIP (JW, windowed) | 18-PDIP (plastic, OTP) | 18-PDIP (plastic, OTP) |
| Program Memory | 1.5 KB (1K x 12) | 768 B (512 x 12) | 768 B (512 x 14) | 512 B (256 x 14) | 1.5 KB (1K x 12) | 1.5 KB (1K x 12) |
| Instruction Set Width | 12-bit baseline | 12-bit baseline | 14-bit mid-range | 14-bit mid-range | 12-bit baseline | 12-bit baseline |
| Maximum Clock | 20 MHz | 20 MHz | 20 MHz | 20 MHz | 4 MHz | 20 MHz |
| RAM | 25 bytes | 25 bytes | 25 bytes | 25 bytes | 25 bytes | 25 bytes |
| I/O Pins | 12 | 12 | 12 | 12 | 12 | 12 |
| EPROM Window | Yes (UV-erasable) | Yes (UV-erasable) | Yes (UV-erasable) | Yes (UV-erasable) | No (OTP) | No (OTP) |
| Unit Price (qty 1) | $12.50 | $11.80 | $13.20 | $10.50 | $3.40 | $3.95 |
Key Differentiators
- Windowed ceramic package allows UV erasure and reprogramming (vs PIC16C56-20/P (plastic OTP))
- Baseline 12-bit RISC instruction set is simpler to learn (vs PIC16C558/JW (14-bit mid-range))
- 1.5 KB EPROM is sufficient for typical 1K-instruction programs (vs PIC16C55/JW (768 bytes EPROM))
Design Notes
A common mistake is selecting the JW windowed ceramic part for production builds. The windowed CERDIP package is intended only for development and prototyping because each JW part costs 3-4x more than the equivalent OTP plastic-DIP variant (PIC16C56-04/P or PIC16C56-20/P) and the UV-erasable window makes it unsuitable for many end-use environments. Use the JW device for firmware development, then migrate to the OTP or QTP (ROM) variant for volume production. Per the Microchip datasheet, JW parts should be kept in opaque conductive foam when not installed to prevent EPROM corruption from ambient UV.
When laying out the 18-pin CERDIP footprint, route the MCLR/VPP pin (pin 1) with a 10 kohm pull-up to VDD and place a 0.1 uF decoupling capacitor within 5 mm of the VDD pin. Use a 4-pin ceramic resonator or crystal between OSC1 (pin 18) and OSC2 with 22 pF load capacitors to GND. Keep high-current switching traces (LED drivers, relay coils) at least 5 mm away from the OSC traces to prevent injection of supply noise into the clock. Add a 100 uF bulk capacitor near the board power-entry point.
Estimated: at maximum clock (20 MHz), VDD = 5.5 V, and all 12 I/O pins sourcing 20 mA simultaneously, the PIC16C56/JW dissipates approximately (5.5 V x 12 mA quiescent) + (5.5 V x 20 mA x 12 outputs) = approximately 1.33 W. The 18-pin CERDIP has theta_JA of approximately 60 C/W, producing an 80 C junction temperature rise above ambient. At 25 C ambient, junction reaches 105 C, which is within the 150 C maximum. At 70 C ambient, junction reaches 150 C - derate I/O sourcing or reduce clock speed above 60 C ambient.
Compliance Information
RoHS-compliant ceramic DIP package per Microchip product page. Not AEC-Q100 qualified; for automotive applications use AEC-Q100 qualified PIC16F variants. Lead-free and halogen-free construction.
