PIC16C57-HSI/P - 8-Bit 20MHz OTP MCU, 3KB EPROM | Microchip
MPN: PIC16C57-HSI/P ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $2.95 | $2.95 |
| 10 | $2.66 | $26.60 |
| 100 | $2.36 | $236.00 |
| 500 | $2.12 | $1,060.00 |
| 1,000 | $1.89 | $1,890.00 |
PIC16C57-HSI/P Overview
A microcontroller (MCU) is a single-chip computer that integrates a CPU core, non-volatile program memory, volatile working RAM, and configurable peripheral I/O onto one piece of silicon. The PIC16C5X series uses a 12-bit wide instruction word with an 8-bit data path, achieving roughly 2:1 code compression versus other 8-bit MCUs in its class. Within the broader taxonomy, this part belongs to: microcontroller -> 8-bit MCU -> PIC16 family -> PIC16C5x sub-family -> OTP EPROM variant -> RISC architecture -> CMOS semiconductor. The "HSI" suffix designates a high-speed crystal/oscillator variant rated for 20 MHz operation, while "/P" indicates the PDIP-28 plastic package.
Key features include 33 single-word instructions (single-cycle except branches), a two-level hardware stack, direct/indirect/relative addressing modes, an 8-bit real-time clock/counter (TMR0) with programmable prescaler, power-on reset (POR), watchdog timer (WDT), and a programmable code-protect feature. Operating voltage spans 3.0 V to 5.5 V at industrial temperature range (-40C to +85C). All 20 I/O pins are bidirectional with individually programmable direction registers and high-current sink/source capability.
Typical applications for the PIC16C57-HSI/P include embedded control boards, sensor interface modules, user-interface/keypad controllers, low-cost industrial automation nodes, and legacy system maintenance builds. Its high oscillator frequency makes it suited for applications requiring tighter timing loops than the lower-frequency RC variants (e.g., PIC16C57-RC/P, PIC16C57-LP/P) can deliver.
When designing with this part, note that OTP EPROM cannot be electrically erased - firmware is finalized at programming time. For development cycles, use a windowed CERDIP (-JW) or flash-based PIC16F57 part instead. Decoupling VDD/VSS with 100 nF ceramic caps placed within 5 mm of the pins is recommended; MCLR must be pulled high through a 10 kohm resistor for normal operation.
This page synthesizes distributor pricing, drop-in alternatives, and practical design notes not found in the manufacturer datasheet alone.
Drop-in alternatives for PIC16C57-HSI/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-HSI/P (same form factor and footprint) — differing in Package, Watchdog Timer, Timers, Core Architecture, Program Memory Size.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC16C57C-20I/P
✅ Drop-In📋 Reference alternative (not in catalog)
PIC16C57-HS/P
✅ Drop-In✓ In Stock
$4.62 / Unit
View Datasheet →PIC16C57C-40/P
✅ Drop-In✓ In Stock
$3.82 / Unit
View Datasheet →PIC16C57-10I/P
✅ Drop-In✓ In Stock
$1.75 / Unit
View Datasheet →PIC16F57-I/P
✅ Drop-In📋 Reference alternative (not in catalog)
PIC16C57-HSI/P Maximum Ratings & Electrical Characteristics
| Core Architecture | 8-bit RISC (PIC) |
| Program Memory Type | OTP EPROM |
| Program Memory Size | 3 KB (2K x 12) |
| RAM Size | 72 bytes |
| Maximum CPU Frequency | 20 MHz |
| Instruction Set | 33 instructions, 12-bit wide |
| Operating Voltage (Vdd) | 3.0 V to 5.5 V |
| I/O Pins | 20 |
| Timers | 1 x 8-bit (TMR0 with prescaler) |
| Stack Depth | 2 levels (hardware) |
| Operating Temperature Range | -40C to +85C (industrial) |
| Package | 28-PDIP (DIP-28, 0.600 in) |
| Mounting Type | Through-Hole |
| MSL Level | Not applicable (through-hole) |
| Oscillator Type | HS (high-speed crystal/resonator) |
| Watchdog Timer | Yes (WDT) |
| Power-on Reset | Yes (POR) |
| Code Protection | Programmable |
PIC16C57-HSI/P Pin Configuration
| Pin 1 | RA2 — Bidirectional I/O, bit 2 of PORTA |
| Pin 2 | RA3 — Bidirectional I/O, bit 3 of PORTA |
| Pin 3 | T0CKI — Timer0 clock input / RA4 |
| Pin 4 | MCLR — Master Clear (reset), active low |
| Pin 5 | VSS — Ground reference |
| Pin 6 | RB0 — Bidirectional I/O, bit 0 of PORTB |
| Pin 7 | RB1 — Bidirectional I/O, bit 1 of PORTB |
| Pin 8 | RB2 — Bidirectional I/O, bit 2 of PORTB |
| Pin 9 | RB3 — Bidirectional I/O, bit 3 of PORTB |
| Pin 10 | RB4 — Bidirectional I/O, bit 4 of PORTB |
| Pin 11 | RB5 — Bidirectional I/O, bit 5 of PORTB |
| Pin 12 | RB6 — Bidirectional I/O, bit 6 of PORTB |
| Pin 13 | RB7 — Bidirectional I/O, bit 7 of PORTB |
| Pin 14 | VDD — Positive supply, 3.0 V to 5.5 V |
| Pin 15 | OSC2 — Oscillator output (crystal/HS mode) |
| Pin 16 | OSC1 — Oscillator input (crystal/HS mode) |
| Pin 17 | RC0 — Bidirectional I/O, bit 0 of PORTC |
| Pin 18 | RC1 — Bidirectional I/O, bit 1 of PORTC |
| Pin 19 | RC2 — Bidirectional I/O, bit 2 of PORTC |
| Pin 20 | RC3 — Bidirectional I/O, bit 3 of PORTC |
| Pin 21 | RC4 — Bidirectional I/O, bit 4 of PORTC |
| Pin 22 | RC5 — Bidirectional I/O, bit 5 of PORTC |
| Pin 23 | RC6 — Bidirectional I/O, bit 6 of PORTC |
| Pin 24 | RC7 — Bidirectional I/O, bit 7 of PORTC |
| Pin 25 | RA0 — Bidirectional I/O, bit 0 of PORTA |
| Pin 26 | RA1 — Bidirectional I/O, bit 1 of PORTA |
| Pin 27 | RTCC — Timer0 RTCC signal / RA5 |
| Pin 28 | VDD — Positive supply (secondary pin) |
Typical Applications
PIC16C57-HSI/P is suitable for 6 applications: Embedded Control Boards, Sensor Interface Modules, User Interface / Keypad Controllers, Low-Cost Industrial Automation Nodes, Legacy System Maintenance and Replacement, Educational and Hobby Projects.
Embedded Control Boards
The PIC16C57-HSI/P suits generic 8-bit embedded control tasks where the firmware is finalized and does not require field updates. Its 20 MHz core delivers approximately 5 MIPS, sufficient for state-machine control, simple protocol handling, and timing-sensitive loop tasks. The 20 bidirectional I/O pins comfortably drive seven-segment displays, keypads, relays, and small signal-conditioning chains. Because the device uses OTP EPROM, firmware is committed at programming time, which makes this part ideal for high-volume production boards where cost-per-unit is critical and firmware revision is rare. Industrial temperature grade (-40C to +85C) supports factory-floor and outdoor enclosures.
Recommended
Sensor Interface Modules
For analog and digital sensor front-ends the PIC16C57-HSI/P provides 20 general-purpose I/O plus a hardware 8-bit timer (TMR0) for periodic sampling. With a 20 MHz oscillator, TMR0 can be prescaled to generate precise interrupt-free sample windows up to several kHz. The 3 KB program memory is more than adequate for thermocouple linearization, RTD look-up tables, and calibration constants. Sensor modules built around this part typically run on 5 V rails, which sit comfortably within the 3.0 V to 5.5 V operating range. The 72-byte RAM is sufficient for buffering small sample arrays.
Recommended
User Interface / Keypad Controllers
The 20 I/O pins of the PIC16C57-HSI/P are well-matched to matrix-scanned keypads up to 4x4 plus a small character LCD or LED bank. At 20 MHz the part can debounce keys, drive a 16-character 7-segment display via direct multiplexing, and service a serial back-channel without CPU bottleneck. The PIC16C5X 33-instruction core produces compact scan-loop code, leaving program memory free for menu trees and translation tables. Industrial temperature tolerance allows keypad controllers to be deployed in vehicles, kiosks, and outdoor panels where consumer-grade MCUs would fail.
Recommended
Low-Cost Industrial Automation Nodes
Distributed automation nodes often pair a low-cost MCU with a digital isolator and an RS-485 transceiver. The PIC16C57-HSI/P fits this role with its 20 MHz CPU, 20 I/O, and 3 KB EPROM sufficient for Modbus RTU slave stacks, sensor polling, and local fault handling. Industrial temperature grade and proven reliability over decades of Microchip PIC16C5X deployment make it a trusted choice for safety-adjacent and maintenance-replaceable nodes. OTP EPROM is an asset here because the firmware is fully validated before deployment to the field, eliminating risk of accidental reprogramming.
Recommended
Legacy System Maintenance and Replacement
Many industrial and scientific instruments deployed in the late 1990s and 2000s use PIC16C5X-family MCUs that are now reaching end-of-life or have become hard to source. The PIC16C57-HSI/P is still in active production and provides a direct like-for-like replacement in the 28-pin PDIP footprint. Industrial maintenance engineers keep stock of this part for board-repair operations on legacy automation, medical instrumentation, and laboratory equipment where redesign is uneconomical. The 20 MHz HS oscillator variant matches the original part specification, eliminating the need for crystal retuning or timing recalculation.
Recommended
Educational and Hobby Projects
The PIC16C57-HSI/P is widely used in undergraduate embedded systems courses and hobby projects because the PIC16C5X instruction set is small (33 instructions) and easily learned in assembly. The 28-pin PDIP package is breadboard-friendly and pairs naturally with classic PIC development boards and the MPLAB PM3 programmer. The PIC's RISC architecture and 2:1 code compression over CISC 8-bit MCUs make it ideal for teaching efficient embedded programming. Note that the OTP EPROM is one-time programmable; educational users should buy a few extra parts or use a flash-based PIC16F57 for repeated re-programming during the learning cycle.
Recommended
Recommended Products Summary
Engineering reference data for PIC16C57-HSI/P — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16C57C-20I/P | PIC16C57-HS/P | PIC16C57C-40/P | PIC16C57-10I/P | PIC16F57-I/P |
|---|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 28-PDIP | 28-PDIP - same | 28-PDIP - same | 28-PDIP - same | 28-PDIP - same | 28-PDIP - same |
| Program Memory Type | OTP EPROM | Flash | OTP EPROM | Flash | OTP EPROM | Flash |
| Program Memory Size | 3 KB (2K x 12) | 3 KB | 3 KB | 3 KB | 3 KB | 3 KB |
| Maximum CPU Frequency | 20 MHz | 20 MHz | 20 MHz | 40 MHz | 10 MHz | 20 MHz |
| RAM Size | 72 bytes | 72 bytes | 72 bytes | 72 bytes | 72 bytes | 72 bytes |
| I/O Pins | 20 | 20 | 20 | 20 | 20 | 20 |
| Operating Temperature | -40C to +85C (industrial) | -40C to +85C (industrial) | 0C to +70C (commercial) | 0C to +70C (commercial) | -40C to +85C (industrial) | -40C to +85C (industrial) |
| In-System Reprogramming | No (OTP) | Yes (flash) | No (OTP) | Yes (flash) | No (OTP) | Yes (flash, ICD) |
Key Differentiators
- Industrial temperature grade OTP EPROM in 28-PDIP (vs PIC16C57-HS/P)
- 20 MHz high-speed oscillator variant (vs PIC16C57-LP/P)
- Authentic OTP EPROM for non-reprogrammable production (vs PIC16C57C-20I/P (flash))
Design Notes
Decouple VDD (pin 14) and the secondary VDD (pin 28) with a 100 nF ceramic capacitor placed within 5 mm of each pin; add a bulk 10 uF tantalum or aluminum electrolytic cap on the supply rail near the MCU. The PIC16C5X series is sensitive to supply droop during oscillator startup; if MCLR is held low during power ramp, ensure VDD has reached Vbor (brown-out threshold) before releasing MCLR to guarantee a clean POR. For battery-powered designs, the PIC16C57-10I/P LP variant consumes significantly less power at the cost of CPU speed.
OTP EPROM cannot be electrically erased. Each failed firmware build consumes a device. For development, use a windowed PIC16C57-JW (CERDIP with quartz window) or the flash-based PIC16F57-I/P. Do not assume code protection bit is automatically cleared - per datasheet section 8.4, code protection must be explicitly programmed and is non-reversible. Also note the 2-level hardware stack: nested subroutines deeper than 2 levels will wrap and corrupt the return address - this is a frequent source of bugs ported from 16F-series code.
Keep the 20 MHz crystal traces on OSC1 (pin 16) and OSC2 (pin 15) as short as possible (under 10 mm), surrounded by a ground pour, and place load capacitors (typically 15-33 pF) within 3 mm of the oscillator pins. Avoid routing digital signal traces under or near the crystal traces to prevent coupling. The MCLR pin (pin 4) should be pulled high through a 10 kohm resistor; if a manual reset pushbutton is needed, place it close to the pin with a 100 nF decoupling cap to suppress switch bounce. PORTA pins RA0-RA3, RA4 (T0CKI) and RA5 (RTCC) are particularly sensitive to capacitive loading on the timer functions.
Compliance Information
RoHS and lead-free status not explicitly stated in verified distributor data for this OTP EPROM PDIP variant; confirm with Microchip's latest material declaration before volume orders. Not AEC-Q100 qualified - this is a general-purpose industrial MCU, not automotive grade.
