PIC16C57-XTI/P - 8-Bit 4MHz 3KB OTP MCU 28-PDIP | Microchip
MPN: PIC16C57-XTI/P ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $8.62 | $8.62 |
| 10 | $7.75 | $77.50 |
| 100 | $6.8 | $680.00 |
| 500 | $6.1 | $3,050.00 |
| 1,000 | $5.55 | $5,550.00 |
PIC16C57-XTI/P Overview
An 8-bit microcontroller (MCU) is a single-chip computer containing a CPU, program memory, data RAM, and peripheral interfaces on one die. Within the broader taxonomy, the PIC16C57 belongs to the 8-bit MCU hypernym -> microcontroller family -> embedded IC -> semiconductor. The 'C' suffix indicates CMOS EPROM/OTP program memory (versus 'F' for Flash and 'CR' for ROM), and the PIC16C5X series is one of Microchip's foundational mid-range architectures predating the later PIC16F and PIC18 families. OTP memory is programmed once and is non-erasable, which makes the part cost-effective for high-volume production but unsuitable for firmware revision.
Key features of the PIC16C57-XTI/P include 12-bit instruction width, 33 single-cycle instructions (excluding branches), two 8-bit timer/counters (TMR0 with 8-bit programmable prescaler, TMR1), a watchdog timer with on-chip RC oscillator, and a power-on reset (POR) circuit. The device operates over a 2.5V to 6.25V VDD range and consumes very low operating current thanks to its CMOS design. The -XTI suffix designates a 4 MHz crystal/oscillator industrial-temperature-grade variant in PDIP packaging.
Architecturally, the PIC16C57 uses a 2-stage pipeline with an 8-bit data path and a separate 12-bit program path (Harvard architecture). Its 8-level deep hardware stack limits subroutine nesting to 8 levels, which constrains complex C compilers but suits compact assembly-level firmware. The device has four interrupt sources with a fixed interrupt vector and supports direct, indirect, and relative addressing modes.
Typical applications include consumer appliance controls, automotive body electronics (non-safety), industrial sensor front-ends, low-cost remote controls, and battery-powered metering. The 20 available I/O pins make it well-suited to small user-interface boards and LED/keypad scan matrices. Because the PIC16C57 is mature and well-documented, it remains popular in maintenance-of-existing-design and legacy industrial equipment scenarios.
When designing with the PIC16C57-XTI/P, engineers should use the MPLAB PM3 Universal Device Programmer (or a compatible gang programmer) and the MPLAB IDE v8.x or earlier for assembly development. Designers must budget the 8-level hardware stack carefully and avoid C compilers that require deep call nesting. For new designs, the PIC16F57 or PIC16F57 Flash variant offers in-circuit reprogrammability with pin-compatible migration paths.
This page synthesizes distributor pricing, drop-in alternatives, and practical design notes not found on a single manufacturer or distributor datasheet page.
Drop-in alternatives for PIC16C57-XTI/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-XTI/P (same form factor and footprint) — differing in Package, Program Memory Size, Operating Temperature, Program Memory Type, Timers.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC16F57-I/P
✅ Drop-In📋 Reference alternative (not in catalog)
PIC16C57-XT/P
✅ Drop-In✓ In Stock
$2.95 / Unit
View Datasheet →PIC16C57C-20I/P
✅ Drop-In✓ In Stock
$2.18 / 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 →PIC16C57-XTI/P Maximum Ratings & Electrical Characteristics
| Core Architecture | PIC 8-bit RISC (Harvard) |
| Instruction Set Width | 12-bit |
| Number of Instructions | 33 (excluding branches) |
| Program Memory Type | OTP EPROM (One-Time-Programmable) |
| Program Memory Size | 3 KB (2K x 12) |
| Data RAM | 72 bytes |
| Maximum CPU Frequency | 4 MHz |
| I/O Pins | 20 |
| Timers | TMR0 (8-bit with prescaler), TMR1 (8-bit) |
| Watchdog Timer | Yes (with on-chip RC oscillator) |
| Hardware Stack Depth | 8 levels |
| Supply Voltage (VDD) | 2.5 V to 6.25 V |
| Operating Temperature | -40 C to +85 C (Industrial) |
| Package | 28-pin PDIP (0.600", 15.24 mm) |
| Mounting Type | Through-Hole (DIP) |
PIC16C57-XTI/P Pin Configuration
| Pin 1 | RA2 — Port A bit 2 (digital I/O) |
| Pin 2 | RA3 — Port A bit 3 (digital I/O) |
| Pin 3 | RA4/T0CKI — Port A bit 4 / Timer 0 clock input |
| Pin 4 | RA0 — Port A bit 0 (digital I/O) |
| Pin 5 | RA1 — Port A bit 1 (digital I/O) |
| Pin 6 | OSC1/CLKIN — Crystal oscillator input / external clock input |
| Pin 7 | RB0 — Port B bit 0 (digital I/O, interrupt-on-change capable) |
| Pin 8 | RB1 — Port B bit 1 (digital I/O) |
| 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 | VSS — Ground reference |
| Pin 15 | RC0 — Port C bit 0 (digital I/O) |
| Pin 16 | RC1 — Port C bit 1 (digital I/O) |
| Pin 17 | RC2 — Port C bit 2 (digital I/O) |
| Pin 18 | RC3 — Port C bit 3 (digital I/O) |
| Pin 19 | RC4 — Port C bit 4 (digital I/O) |
| Pin 20 | RC5 — Port C bit 5 (digital I/O) |
| Pin 21 | RC6 — Port C bit 6 (digital I/O) |
| Pin 22 | RC7 — Port C bit 7 (digital I/O) |
| Pin 23 | VSS — Ground reference (auxiliary) |
| Pin 24 | VDD — Positive supply voltage |
| Pin 25 | VDD — Positive supply voltage (auxiliary) |
| Pin 26 | OSC2/CLKOUT — Crystal oscillator output / clock output |
| Pin 27 | NC — Not connected (per datasheet) |
| Pin 28 | /MCLR — Master clear reset (active-low) |
Typical Applications
PIC16C57-XTI/P is suitable for 7 applications: Consumer Appliance Control, Automotive Body Electronics (Non-Safety), Industrial Sensor Front-End, Remote Control and IR Transmitter, Battery-Powered Metering, Legacy Industrial Equipment Maintenance, Educational and Hobbyist Embedded Projects.
Consumer Appliance Control
The PIC16C57-XTI/P fits consumer appliance control boards because of its 20 I/O pins, low-cost OTP memory, and 4 MHz CPU clock which is sufficient for keypad scan, LED multiplexing, and relay/triac drive sequencing. The 33-instruction 12-bit core executes typical appliance logic in roughly 1-2 KB of code, fitting inside the 3 KB OTP budget with margin for state-machine extensions. Industrial temperature rating (-40C to +85C) supports kitchen and laundry environments where ambient can exceed 70C behind the control panel. Compared to Flash-based PIC16F57, the OTP variant offers lower unit cost at volumes above 10K pieces where field firmware updates are not required.
Recommended
Automotive Body Electronics (Non-Safety)
The PIC16C57-XTI/P is suitable for automotive body-control modules such as interior lighting, mirror adjust, and seat-position controllers, where the industrial -40C to +85C temperature range handles cabin environments and 20 I/O pins cover keypad input plus H-bridge enable outputs. The 4 MHz CPU clock is adequate for LIN-bite software-UART or simple PWM-based motor control at modest update rates. Note: this part is NOT AEC-Q100 qualified - for safety-critical or under-hood ECUs, designers must select AEC-Q100 grade PIC16F counterparts instead. The 72-byte RAM limits LIN message buffering, so the PIC16C57 fits best in slave-node body controllers with short frame handling.
Recommended
Industrial Sensor Front-End
The PIC16C57-XTI/P serves industrial 4-20 mA loop-powered sensor transmitters and remote sensor-conditioning modules that need only a handful of I/O and modest compute. The 8-bit ADC-free architecture pairs naturally with external sigma-delta ADCs (e.g., MCP3551) over SPI, and the 4 MHz clock provides 1 MIPS execution speed which is sufficient for linearization and HART-state-machine emulation in loop-powered heads. The wide 2.5V-6.25V VDD range allows direct connection to unregulated 5V industrial rails without an additional LDO. The -40C to +85C temperature range covers ISA-71.04 Class G3 industrial environments and most outdoor enclosures.
Recommended
Remote Control and IR Transmitter
The PIC16C57-XTI/P is well-matched to low-cost IR/RF remote control handsets where the 20 I/O pins drive a 4x5 keypad matrix plus an IR LED PWM output, and the 4 MHz clock generates 38 kHz / 56 kHz carrier frequencies with software PWM. The 3 KB OTP memory holds large IR-code libraries (NEC, RC5, RC6, SIRC) comfortably. The low operating current (CMOS, <2 mA active at 4 MHz / 5V) extends battery life in coin-cell or AAA-powered handsets. Watchdog timer with on-chip RC oscillator provides brown-out protection without external components.
Recommended
Battery-Powered Metering
The PIC16C57-XTI/P suits battery-powered metering devices like water/gas meters, electronic thermostats, and small portable instruments where its low-power CMOS design and 2.5V minimum VDD enable direct Li-coin-cell operation. The watchdog timer with internal RC oscillator lets the MCU wake from sleep every 2-3 seconds, take a sensor reading, and return to sleep with average current below 10 uA. The 4 MHz CPU clock handles BCD-to-binary conversion, LCD multiplexing for 4-digit displays, and pulse-counting for meter flow sensors. Industrial temperature range ensures operation in outdoor metering cabinets.
Recommended
Legacy Industrial Equipment Maintenance
The PIC16C57-XTI/P is most commonly sourced today for maintenance-of-existing-equipment (MROE) scenarios in industrial automation where decades-old PLCs, motor drives, and textile machinery still operate on PIC16C5X-based controller boards. Its mature, stable silicon avoids the redesign risk of cross-package migration, and the 28-PDIP through-hole package suits older wave-soldered assemblies where SMD migration would require a full board re-spin. Distributors continue to stock this part precisely because field failures of 1990s-era equipment require exact-form-factor replacements, not pin-compatible upgrades.
Recommended
Educational and Hobbyist Embedded Projects
The PIC16C57-XTI/P is widely used in educational settings and hobbyist electronics because the PIC16C5X architecture is the canonical introduction to Microchip's instruction set and the datasheet is a model of clarity for learning register-level programming. The 28-PDIP package fits standard 0.1" pitch breadboards without SMD adapters, and the 4 MHz clock is slow enough to debug with LED-based step indicators. While OTP prevents iterative reprogramming in lab use, the low per-unit cost makes the part viable for one-shot class projects. The MPLAB PM3 and ICD-like debuggers from Microchip support the PIC16C5X family fully.
Recommended
Recommended Products Summary
Engineering reference data for PIC16C57-XTI/P — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16F57-I/P | PIC16C57-XT/P | PIC16C57C-20I/P | PIC16C57C-40/P | PIC16C57-10I/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) |
| Maximum CPU Frequency | 4 MHz | 4 MHz | 4 MHz | 20 MHz | 40 MHz | 10 MHz |
| Program Memory Type | OTP EPROM (3 KB) | Flash (3 KB) | OTP EPROM (3 KB) | OTP EPROM (3 KB) | OTP EPROM (3 KB) | OTP EPROM (3 KB) |
| Data RAM | 72 bytes | 72 bytes | 72 bytes | 72 bytes | 72 bytes | 72 bytes |
| I/O Pins | 20 | 20 | 20 | 20 | 20 | 20 |
| Operating Temperature Range | -40 C to +85 C (Industrial) | -40 C to +85 C (Industrial) | 0 C to +70 C (Commercial) | -40 C to +85 C (Industrial) | 0 C to +70 C (Commercial) | -40 C to +85 C (Industrial) |
| Supply Voltage (VDD) | 2.5 V to 6.25 V | 2.0 V to 5.5 V | 2.5 V to 6.25 V | 2.5 V to 6.25 V | 2.5 V to 6.25 V | 2.5 V to 6.25 V |
Key Differentiators
- Industrial temperature grade in 28-PDIP at commercial cost (vs PIC16C57-XT/P)
- Pin-compatible migration path to Flash memory (vs PIC16F57-I/P)
- 5x higher CPU clock available in same package (vs PIC16C57C-20I/P)
Design Notes
The PIC16C57-XTI/P in 28-PDIP packaging has very low power dissipation, typically under 25 mW at 4 MHz / 5V, and requires no thermal management beyond standard PCB layout. Designers should ensure the /MCLR pull-up resistor (typically 10 kohm) is placed within 1 inch of the /MCLR pin to avoid spurious resets from switching transients coupling into the reset line.
When laying out the 28-PDIP footprint, allow 0.1 inch (2.54 mm) row spacing and 0.6 inch (15.24 mm) row-to-row pitch to accept standard DIP sockets and clip-on programmers. Place the decoupling capacitor (100 nF ceramic + 10 uF electrolytic) within 5 mm of VDD pins 24-25. Keep the crystal/ceramic resonator traces short and route the OSC1/OSC2 pair together with a ground guard ring to avoid injecting noise into the internal oscillator amplifier.
Estimated: The 8-level hardware stack means deeply nested C functions will overflow and corrupt RAM. A typical assembly-style C limit is 4-5 call frames before stack corruption becomes likely. Code must be written defensively to keep call depth flat. The OTP memory cannot be erased; a single programming mistake renders the device unusable. Always use a Flash-based PIC16F57 or PIC16F84A emulator for firmware development, then port the final hex to the PIC16C57-XTI/P only after full validation.
Brown-out detection is not present on the PIC16C57-XTI/P; engineers must add an external voltage supervisor (e.g., MCP100 or MCP102) if VDD can dip below 2.5V during motor-start or load-dump transients. The POR circuit relies on VDD rise-time; for slow-rising supplies, the device may enter undefined states. The watchdog timer should be enabled in any application where software lockup could cause safety or equipment damage.
Compliance Information
RoHS, REACH, lead-free, and halogen-free status not explicitly stated in verified web data; the 28-PDIP package is a through-hole variant likely available in both leaded and lead-free finishes - confirm with manufacturer documentation before production. The PIC16C57-XTI/P is not AEC-Q100 qualified; AEC-Q100 grades exist only in the PIC16F family.
