PIC16C57-RCI/P - 8-Bit 4MHz OTP MCU 3KB | Microchip | DIP-28
MPN: PIC16C57-RCI/P ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $7.17 | $7.17 |
| 10 | $6.45 | $64.50 |
| 100 | $5.74 | $574.00 |
| 500 | $5.16 | $2,580.00 |
| 1,000 | $4.62 | $4,620.00 |
PIC16C57-RCI/P Overview
An OTP microcontroller is a member of the microcontroller family in which the program memory can be written only once by the user using a device programmer, after which the code becomes permanent. The PIC16C57 belongs to the PIC16C5X family, which sits in the broader hierarchy: PIC microcontroller -> 8-bit RISC MCU -> microcontroller unit (MCU) -> embedded controller -> semiconductor. The 12-bit wide instruction word enables compact code density and a 33-instruction RISC instruction set, which historically delivered significantly higher MIPS-per-dollar than competing 8-bit CISC controllers.
Key features include 4 MHz maximum operating frequency, 2K x 12 (3KB) OTP EPROM program memory, 72 bytes of general-purpose RAM, 20 digital I/O pins, an internal RC oscillator option (denoted by the 'RC' in the part number), and a wide 3.0V to 5.5V operating voltage range. The 28-pin PDIP package is widely used for legacy designs, hobbyist prototyping, and educational applications where socketed, hand-solderable parts are preferred over surface-mount alternatives.
The PIC16C57 architecture uses a Harvard-style memory structure with separate program and data buses, which allows instruction fetch and data access to occur in the same instruction cycle. With 4 MHz clock and a 4:1 internal divider, the instruction cycle is 1 microsecond, providing roughly 1 MIPS of throughput. Although modest by modern standards, this is adequate for simple control loops, sensor interfacing, and standalone embedded tasks.
Typical applications include legacy industrial control boards, hobbyist projects, educational microcontroller trainers, simple sensor interface boards, and replacement of older PIC16C5X designs in long-lifecycle equipment. The OTP nature means each unit is programmed once during manufacturing or board bring-up, making it best suited for low-to-medium volume production where firmware is stable and final.
When designing with this device, note that the OTP memory cannot be reprogrammed in-circuit; the MPLAB PM3 Universal Device Programmer is required for code loading. For new designs requiring in-circuit reprogrammability, consider migrating to the flash-based PIC16F57 family, which shares pinout but adds Flash memory and ICSP support.
Drop-in alternatives for PIC16C57-RCI/P — 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 PIC16C57-RCI/P (same form factor and footprint) — differing in Package, Timers, Program Memory Size, Maximum Clock Frequency, Oscillator Type.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC16C57C-20/P
✅ Drop-In✓ In Stock
$2.45 / Unit
View Datasheet →PIC16C57-10I/P
✅ Drop-In✓ In Stock
$1.75 / Unit
View Datasheet →PIC16C57-LPI/P
✅ Drop-In✓ In Stock
$1.95 / Unit
View Datasheet →PIC16C57-HSI/P
✅ Drop-In✓ In Stock
$1.89 / Unit
View Datasheet →PIC16C57-RC/SO
✅ Drop-In✓ In Stock
$4.75 / Unit
View Datasheet →PIC16C57-LPE/P
✅ Drop-In✓ In Stock
$2.7 / Unit
View Datasheet →PIC16C57-RCI/P Maximum Ratings & Electrical Characteristics
| Core | PIC16 8-bit RISC |
| Architecture | Harvard, 12-bit instruction word |
| Program Memory Type | OTP EPROM |
| Program Memory Size | 3KB (2K x 12) |
| RAM Size | 72 bytes |
| EEPROM Size | None |
| Maximum Clock Frequency | 4 MHz |
| Instruction Cycle Time | 1 us @ 4 MHz |
| Operating Voltage | 3.0V to 5.5V |
| I/O Pins | 20 |
| Oscillator Type | External RC (RC variant) |
| Instruction Set | 33 single-word instructions |
| Package | 28-pin PDIP (0.600 inch, 15.24mm) |
| Mounting Type | Through-hole (DIP) |
| Operating Temperature Range | 0C to +70C (commercial) |
| Data Bus Width | 8-bit |
| Program Bus Width | 12-bit |
PIC16C57-RCI/P Pin Configuration
| Pin 1 | RA2 — Port A bit 2 (bidirectional I/O) |
| Pin 2 | RA3 — Port A bit 3 (bidirectional I/O) |
| Pin 3 | RTCC — Real-Time Clock/Counter input |
| Pin 4 | MCLR — Master Clear (active-low reset) |
| Pin 5 | VSS — Ground reference |
| Pin 6 | RB0 — Port B bit 0 (bidirectional I/O) |
| Pin 7 | RB1 — Port B bit 1 (bidirectional I/O) |
| Pin 8 | RB2 — Port B bit 2 (bidirectional I/O) |
| Pin 9 | RB3 — Port B bit 3 (bidirectional I/O) |
| Pin 10 | RB4 — Port B bit 4 (bidirectional I/O) |
| Pin 11 | RB5 — Port B bit 5 (bidirectional I/O) |
| Pin 12 | RB6 — Port B bit 6 (bidirectional I/O) |
| Pin 13 | RB7 — Port B bit 7 (bidirectional I/O) |
| Pin 14 | VDD — Positive supply voltage (3.0V-5.5V) |
| Pin 15 | RC0 — Port C bit 0 (bidirectional I/O) |
| Pin 16 | RC1 — Port C bit 1 (bidirectional I/O) |
| Pin 17 | RC2 — Port C bit 2 (bidirectional I/O) |
| Pin 18 | RC3 — Port C bit 3 (bidirectional I/O) |
| Pin 19 | RC4 — Port C bit 4 (bidirectional I/O) |
| Pin 20 | RC5 — Port C bit 5 (bidirectional I/O) |
| Pin 21 | RC6 — Port C bit 6 (bidirectional I/O) |
| Pin 22 | RC7 — Port C bit 7 (bidirectional I/O) |
| Pin 23 | RD0 — Port D bit 0 (bidirectional I/O) |
| Pin 24 | RD1 — Port D bit 1 (bidirectional I/O) |
| Pin 25 | RD2 — Port D bit 2 (bidirectional I/O) |
| Pin 26 | RD3 — Port D bit 3 (bidirectional I/O) |
| Pin 27 | RD4 — Port D bit 4 (bidirectional I/O) |
| Pin 28 | RD5/OSC1 — Port D bit 5 / oscillator input (RC variant) |
Typical Applications
PIC16C57-RCI/P is suitable for 7 applications: Legacy Industrial Control Boards, Educational Microcontroller Trainers, Hobbyist and Maker Projects, Sensor Interface and Signal Conditioning, Simple Standalone Embedded Controllers, Replacement and Repair of Legacy PIC16C5X Designs, Automotive Sub-Controller Modules.
Legacy Industrial Control Boards
The PIC16C57-RCI/P fits long-lifecycle industrial control boards where the firmware has been stable for decades and a drop-in OTP controller is preferred over redesigning with a flash MCU. With 20 I/O lines it can drive relays, read limit switches, and interface to 7-segment displays via port multiplexing. Its 3KB OTP memory accommodates typical state-machine control code. The 4 MHz clock and 1 us instruction cycle handle sampling loops and debounce timing comfortably, while the 3.0V-5.5V supply range lets it operate from 24V industrial rails via simple linear regulation.
Recommended
Educational Microcontroller Trainers
The PIC16C57-RCI/P is widely used in university and trade-school microcontroller courses because its 28-pin PDIP is easy to breadboard and socket, the 33-instruction RISC set is beginner-friendly, and the 20 I/O pins give students enough resources to drive LEDs, read buttons, and interface simple sensors. The OTP constraint forces proper code pre-verification before burning, reinforcing engineering discipline. Its 1 MIPS throughput is sufficient to demonstrate real-time concepts without overwhelming the educational pace.
Recommended
Hobbyist and Maker Projects
Hobbyists favor the PIC16C57-RCI/P for permanent installations such as custom LED decorations, sensor loggers, and prop controllers where the one-time-programmed nature guarantees the firmware cannot be accidentally overwritten. Its 4 MHz clock, 20 I/O, and 3.0V-5.5V operation cover most hobbyist needs. The PDIP package accepts standard IC sockets, allowing swap-out of pre-programmed chips for project variants. The wide distributor availability and sub-$5 unit pricing keep project costs low.
Recommended
Sensor Interface and Signal Conditioning
The PIC16C57-RCI/P fits simple sensor interface boards reading switches, thermistors, potentiometers, and basic analog signals via on-chip comparators or external ADC front-ends. With 20 I/O and 4 MHz throughput, it can multiplex multiple sensor channels, perform linearization math, and drive indicator LEDs. The 3.0V-5.5V range supports battery-powered sensor nodes. Its low cost makes it attractive for sensor modules deployed in volume where each node needs its own controller.
Recommended
Simple Standalone Embedded Controllers
Standalone controller applications such as washing-machine sub-controllers, vending machine dispensers, HVAC damper actuators, and appliance timers benefit from the PIC16C57-RCI/P's combination of 20 I/O, OTP memory, and through-hole DIP package that field-service technicians can swap without specialized tools. The 1 MIPS throughput handles sequential control loops and LED multiplexing. The OTP memory ensures firmware cannot be corrupted by software bugs once shipped, providing field reliability.
Recommended
Replacement and Repair of Legacy PIC16C5X Designs
The PIC16C57-RCI/P serves as a direct replacement for end-of-life or hard-to-find PIC16C5X-family microcontrollers in field-deployed equipment that must be repaired rather than replaced. Its identical pinout, instruction set, and OTP programming model allow technician-level swap-in without firmware rewrite. With active stock at major distributors and a 28-pin PDIP form factor that matches existing PCB footprints, it minimizes Mean-Time-To-Repair for legacy industrial, medical, and test equipment still in service.
Recommended
Automotive Sub-Controller Modules
The PIC16C57-RCI/P is suitable for non-safety automotive sub-modules such as accessory controllers, interior lighting drivers, and sensor conditioning boards where 20 I/O and 4 MHz throughput are sufficient. Its industrial temperature variant tolerates under-dash environments. The OTP memory ensures firmware stability across the vehicle lifetime. Note that AEC-Q100 qualification is not applicable to the C57 family; for safety-critical automotive ECUs, migrate to PIC16F or dsPIC families with explicit automotive qualification.
Recommended
Recommended Products Summary
Engineering reference data for PIC16C57-RCI/P — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16C57C-20/P | PIC16C57-10I/P | PIC16C57-LPI/P | PIC16C57-HSI/P |
|---|---|---|---|---|---|
| Package | 28-PDIP | 28-PDIP - same | 28-PDIP - same | 28-PDIP - same | 28-PDIP - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Program Memory | 3KB (2K x 12) OTP | 3KB OTP | 3KB OTP | 3KB OTP | 3KB OTP |
| RAM | 72 bytes | 72 bytes | 72 bytes | 72 bytes | 72 bytes |
| Max Clock Frequency | 4 MHz (RC oscillator) | 20 MHz (crystal) | 10 MHz | Low-power variant | High-speed variant |
| I/O Pins | 20 | 20 | 20 | 20 | 20 |
| Operating Voltage | 3.0V to 5.5V | 3.0V to 5.5V | 3.0V to 5.5V | 2.5V to 6.25V (LP) | 3.0V to 5.5V |
| Temperature Range | 0C to +70C (commercial) | 0C to +70C | -40C to +85C (industrial) | -40C to +85C (industrial) | -40C to +85C (industrial) |
| Memory Type | OTP EPROM | OTP EPROM | OTP EPROM | OTP EPROM | OTP EPROM |
Key Differentiators
- External RC oscillator option for low-cost clock generation (vs PIC16C57C-20/P)
- Drop-in pin compatibility across the PIC16C57 family (vs PIC16F57-I/P)
- Widely stocked at major distributors with sub-$5 volume pricing (vs PIC16C57-LPI/P (low-power variant))
Design Notes
The PIC16C57-RCI/P uses OTP (One-Time-Programmable) memory - code can be burned only once. Verify firmware completely in MPLAB X simulator and on a PIC16F57 equivalent before committing to OTP programming. Unlike flash MCUs, there is no second-chance reprogram. Use a socketed DIP footprint in any prototype so the chip can be swapped during development without desoldering.
Estimated: at 5V supply and 4 MHz RC oscillator, the PIC16C57-RCI/P draws approximately 2-5 mA active current depending on I/O loading. For battery-powered designs, use the PIC16C57-LPI/P variant instead, which is specified for sub-mA active currents. Decouple VDD (pin 14) with a 100 nF ceramic capacitor placed within 5 mm of the pin, plus a 10 uF bulk capacitor on the same rail.
Route the MCLR pin (pin 4) directly to a 10 kohm pull-up to VDD with a 100 nF cap to ground for proper reset behavior. The RC oscillator variant requires an external resistor and capacitor on pin 28 (OSC1/RD5); keep these components within 10 mm of the pin to minimize noise pickup. For switching noise immunity, add a 100 nF bypass cap adjacent to each port cluster (port B at pins 6-13, port C at 15-22).
The 28-pin PDIP through-hole footprint uses 0.100 inch (2.54 mm) pin pitch with 0.600 inch (15.24 mm) row spacing - compatible with standard IC sockets, breadboards, and stripboard. When laying out, allow at least 1 mm annular ring around each through-hole pad for reliable hand-soldering. Leave clearance for a programming clip if the design will use a PIC programmer; otherwise use a ZIF socket for production programming.
Compliance Information
RoHS compliance status not confirmed in the verified web data. The PIC16C57 family was originally released before RoHS mandates (1990s), but Microchip's current active parts typically ship in RoHS-compliant packaging. AEC-Q100 is not applicable - PIC16C57 is not automotive-qualified; for AEC-Q100 designs use PIC16F or dsPIC automotive variants.
