PIC16C57-XT/P - 8-Bit 4MHz OTP MCU, 3KB ROM, 28-PDIP | Microchip
MPN: PIC16C57-XT/P ✗ End of Life| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $4.8 | $4.80 |
| 10 | $4.32 | $43.20 |
| 100 | $3.84 | $384.00 |
| 500 | $3.4 | $1,700.00 |
| 1,000 | $2.95 | $2,950.00 |
PIC16C57-XT/P Overview
What is an 8-bit microcontroller? An 8-bit microcontroller (MCU) is a single-chip computer that processes data 8 bits at a time and integrates a CPU core, program memory, data RAM, and peripherals such as timers, I/O ports, and interrupt controllers into one package. The PIC16C family is the baseline of Microchip's PIC16 lineup, employing a 12-bit instruction word and RISC architecture that achieves roughly 2:1 code compression over competing 8-bit MCUs in the same price tier. It sits within the broader hierarchy MCU -> microcontroller -> embedded processor -> semiconductor.
Key features include a two-level deep hardware stack, direct/indirect/relative addressing modes for both data and instructions, seven or eight special function hardware registers, and an 8-bit real-time clock/counter (TMR0) with an 8-bit prescaler. The device operates from 3.0 V to 5.5 V and supports both power-saving Sleep mode and a Watchdog Timer for unattended or remote applications. The 12-bit wide instruction set is highly orthogonal, simplifying assembly programming and compiler porting.
Technically, the PIC16C57 uses a Harvard architecture with separate program and data buses, allowing instruction fetch and operand access in a single cycle for most instructions. The OTP program memory is programmed once with the MPLAB PM3 Universal Device Programmer and cannot be erased or rewritten, which makes the PIC16C57 ideal for high-volume production where unit cost dominates engineering NRE.
Typical applications include legacy industrial controllers, appliance control boards, automotive body electronics (non-safety), consumer white-goods user interfaces, and educational development platforms. The wide DIP package also makes it a popular choice for hobbyist retrocomputing projects and product prototyping where through-hole assembly remains convenient.
When designing with this part, note that OTP memory cannot be field-updated; for field-upgradable firmware select the flash-based PIC16F57 instead. Always provide a proper oscillator stabilization delay after POR or Wake-up before code execution begins, as defined in the device datasheet.
This page synthesizes distributor pricing, verified drop-in alternatives, and practical design notes not found in the manufacturer datasheet alone, helping engineers source, compare, and design with the PIC16C57-XT/P efficiently.
Drop-in alternatives for PIC16C57-XT/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-XT/P (same form factor and footprint) — differing in Package, Operating Temperature, Timers, Program Memory Type, Core Architecture.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC16F57-I/P
✅ Drop-In📋 Reference alternative (not in catalog)
PIC16F57-E/P
✅ Drop-In📋 Reference alternative (not in catalog)
PIC16C57-XT/P
✅ Drop-In✓ In Stock
$2.95 / Unit
View Datasheet →PIC16C57-HS/P
✅ Drop-In✓ In Stock
$4.62 / Unit
View Datasheet →PIC16C57-LP/P
✅ Drop-In✓ In Stock
$1.74 / Unit
View Datasheet →PIC16C57-XT/P Maximum Ratings & Electrical Characteristics
| Core Architecture | PIC16 8-bit RISC (Harvard) |
| Program Memory Type | OTP (One-Time Programmable) EPROM |
| Program Memory Size | 3 KB (2K x 12 words) |
| Data RAM | 72 bytes |
| Data EEPROM | None |
| Instruction Word Width | 12 bits |
| Maximum Clock Frequency | 4 MHz |
| Oscillator Type (XT) | Crystal / Resonator |
| Supply Voltage Range | 3.0 V to 5.5 V (typical 5 V) |
| I/O Pins | 20 |
| Timers | 1 x 8-bit TMR0 with 8-bit prescaler |
| Hardware Stack Depth | 2 levels |
| Watchdog Timer | Yes |
| Package | 28-pin PDIP (Plastic DIP) |
| Mounting Type | Through-Hole |
| Operating Temperature | 0 C to +70 C (commercial) |
| RoHS Status | Non-compliant (legacy part) |
| Lead-Free | No (SnPb finish on original lots) |
PIC16C57-XT/P Pin Configuration
| Pin 1 | MCLR/VPP — Master Clear reset input / programming voltage |
| Pin 2 | RA0 — Port A bit 0 (digital I/O) |
| Pin 3 | RA1 — Port A bit 1 (digital I/O) |
| Pin 4 | RA2 — Port A bit 2 (digital I/O) |
| Pin 5 | RA3 — Port A bit 3 (digital I/O) |
| Pin 6 | RB0 — Port B bit 0 (digital I/O) |
| Pin 7 | RB1 — Port B bit 1 (digital I/O) |
| Pin 8 | VSS — Ground |
| Pin 9 | RB2 — Port B bit 2 (digital I/O) |
| Pin 10 | RB3 — Port B bit 3 (digital I/O) |
| Pin 11 | RB4 — Port B bit 4 (digital I/O) |
| Pin 12 | RB5 — Port B bit 5 (digital I/O) |
| Pin 13 | RB6 — Port B bit 6 (digital I/O) |
| Pin 14 | RB7 — Port B bit 7 (digital I/O) |
| Pin 15 | OSC1 — Crystal oscillator input (XT mode) |
| Pin 16 | OSC2 — Crystal oscillator output (XT mode) |
| Pin 17 | RC0 — Port C bit 0 (digital I/O) |
| Pin 18 | RC1 — Port C bit 1 (digital I/O) |
| Pin 19 | VSS — Ground (secondary) |
| Pin 20 | VDD — Positive supply 3.0-5.5 V |
| Pin 21 | RC2 — Port C bit 2 (digital I/O) |
| Pin 22 | RC3 — Port C bit 3 (digital I/O) |
| Pin 23 | RC4 — Port C bit 4 (digital I/O) |
| Pin 24 | RC5 — Port C bit 5 (digital I/O) |
| Pin 25 | RC6 — Port C bit 6 (digital I/O) |
| Pin 26 | RC7 — Port C bit 7 (digital I/O) |
| Pin 27 | T0CKI — Timer0 clock input (also shared GPIO) |
| Pin 28 | NC — Not connected (per datasheet pinout) |
Typical Applications
PIC16C57-XT/P is suitable for 6 applications: Legacy Industrial Control Boards, Consumer Appliance User Interfaces, Educational Microcontroller Trainers, Automotive Body Electronics (Non-Safety), Simple Sensor Signal Conditioning, Retrocomputing and Hobby Projects.
Legacy Industrial Control Boards
The PIC16C57-XT/P's 20 GPIO and 8-bit TMR0 timer suit legacy industrial relay drivers, sensor-scanning boards, and conveyor controllers where PCB footprints were locked in 1990s designs. Its 4 MHz clock provides adequate instruction throughput for sequencing scan rates up to 1 MHz while consuming minimal standby current. The 28-PDIP package is through-hole, which simplifies field replacement on legacy control panels. Designers can verify timing and I/O behavior against PIC16F57-I/P using identical instruction cycles, easing drop-in migration when PIC16C57 stock runs out.
Recommended
Consumer Appliance User Interfaces
Appliance front-panel controllers - washing machines, microwave ovens, and HVAC thermostats - often use the PIC16C57-XT/P to scan key matrices and drive 7-segment LED displays. The 20 I/O pins can debounce an 8-key matrix (8x1) or multiplex a 4-digit display, while the 3 KB OTP program memory holds menu tables and timing logic without field updates. Brown-out detection plus the integrated Watchdog Timer keep the controller reliable under noisy mains environments typical of appliance installations.
Recommended
Educational Microcontroller Trainers
Universities and self-taught hobbyists use the PIC16C57-XT/P in breadboard-friendly through-hole trainers because the 28-PDIP package mates directly with solderless breadboards and ZIF sockets. The 12-bit RISC instruction set teaches core MCU concepts - accumulator-less architecture, two-level hardware stack, direct/indirect addressing - without overwhelming beginners. Each student programs the chip once via MPLAB PM3 and exercises TMR0, GPIO interrupts, and Watchdog reset, building the foundational skills needed for modern PIC16F1xxx designs.
Recommended
Automotive Body Electronics (Non-Safety)
Pre-CAN automotive body modules - interior lighting controllers, wiper timers, and seat-memory switches - deployed the PIC16C57-XT/P because of its small footprint, OTP cost advantage, and sufficient GPIO count. While the C57 is not AEC-Q100 qualified, factory-programmed OTP units were widely used in sealed body-control ECUs where field reprogramming was never required. New automotive designs now use PIC16F57 or PIC16F1xxx with CAN FD peripherals, but the C57 remains in service in millions of legacy vehicles.
Recommended
Simple Sensor Signal Conditioning
The PIC16C57-XT/P's TMR0 and 20 I/O pins make it a fit for low-speed sensor front-ends that count pulses, measure period, or generate PWM. Examples include tachometer pickups, simple thermistor-reading circuits, and opto-interruptor counters. At 4 MHz the 8-bit counter overflows every 64 microseconds, giving sub-millisecond timing resolution sufficient for HVAC and process-control loops. Because the program is OTP, the calibration coefficients are baked in at production and cannot drift in the field.
Recommended
Retrocomputing and Hobby Projects
Retrocomputing enthusiasts use the PIC16C57-XT/P to build replica 1990s microcontroller trainer boards, programmable LED chasers, and breadboard game consoles. The DIP-28 package is ideal for point-to-point wiring on perfboard, and the obsolete status keeps the part cheap on the secondary market. Its 12-bit instruction set and 2-level hardware stack are deliberately simple, which makes it a fun teaching vehicle for assembly-language programmers who want to understand the PIC16 roots before moving to modern MIPS-based PIC32 parts.
Recommended
Recommended Products Summary
Engineering reference data for PIC16C57-XT/P — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16F57-I/P | PIC16F57-E/P | PIC16C57-HS/P | PIC16C57-LP/P |
|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 28-PDIP (through-hole) | 28-PDIP - same | 28-PDIP - same | 28-PDIP - same | 28-PDIP - same |
| Program Memory Type | OTP EPROM (3 KB) | Flash (3 KB) | Flash (3 KB) | OTP EPROM (3 KB) | OTP EPROM (3 KB) |
| Maximum Clock Frequency | 4 MHz (XT) | 4 MHz (XT, identical) | 4 MHz (XT, identical) | 20 MHz (HS) | 200 kHz (LP) |
| Field Reprogrammable | No (OTP) | Yes (Flash, ICSP) | Yes (Flash, ICSP) | No (OTP) | No (OTP) |
| Operating Temperature | 0 C to +70 C | -40 C to +85 C (industrial) | 0 C to +70 C (commercial) | 0 C to +70 C | 0 C to +70 C |
| Lifecycle Status | Obsolete | Active | Active | Obsolete | Obsolete |
| I/O Pins | 20 | 20 | 20 | 20 | 20 |
| Estimated Unit Price (qty 100) | $3.84 | $2.10 | $2.00 | $3.84 | $3.84 |
Key Differentiators
- True flash-reprogrammable drop-in available from same manufacturer (vs PIC16F57-I/P)
- Higher-speed oscillator mode available in same package (vs PIC16C57-HS/P)
- Lower-power oscillator mode for battery-friendly designs (vs PIC16C57-LP/P)
Design Notes
Estimated: Programming the PIC16C57-XT/P requires the Microchip MPLAB PM3 or equivalent high-voltage OTP programmer; the part has no ICSP and no debug interface. Attempting in-circuit programming via PGC/PGD will fail because those pins do not exist on the C57 family. Plan programming step into the production line before PCB assembly, as a programmed part cannot be erased or recovered.
Keep the external crystal or resonator within 0.5 inch (12 mm) of pins 15 (OSC1) and 16 (OSC2) to minimize stray capacitance and startup problems. Add a 1 M-ohm parallel feedback resistor across the crystal to bias the internal oscillator inverter into its linear region at XT-mode frequencies. Route VDD traces first with a 100 nF decoupling cap placed as close to pin 20 as possible, with a bulk 10 uF tantalum nearby for supply transients.
Estimated: At VDD=5 V and fOSC=4 MHz, the PIC16C57-XT/P draws roughly 2 mA active and 5 uA in Sleep mode (Watchdog disabled), per the PIC16C5X datasheet typical curves. Brown-out conditions are not internally detected by the C57, so add an external voltage supervisor (such as MCP100) tied to MCLR if the design operates from unregulated supplies. Account for the 72 ms oscillator stabilization delay defined in the configuration word after POR or Wake-up before executing code that reads peripherals.
Compliance Information
Legacy OTP part, original lots used SnPb lead finish and are not RoHS-compliant. Not AEC-Q100 qualified; not intended for automotive safety applications. Reach compliance status inferred from standard Microchip declarations, not separately verified for this part number.
