PIC16F57-I/SO - 8-bit 20MHz 3KB Flash MCU | Microchip | 28-SOIC
MPN: PIC16F57-I/SO ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $2.18 | $2.18 |
| 10 | $1.95 | $19.50 |
| 100 | $1.62 | $162.00 |
| 500 | $1.38 | $690.00 |
| 1,000 | $1.21 | $1,210.00 |
PIC16F57-I/SO Overview
Background: An 8-bit microcontroller (MCU) is a single-chip computer integrating a CPU, non-volatile program memory (Flash/ROM), working RAM, and peripheral I/O on one die. The PIC16F5X family is one of the original baseline PIC architectures and belongs to the broader Microchip PIC16 -> 8-bit MCU -> microcontroller -> embedded controller -> semiconductor taxonomy. Its 12-bit-wide opcode is an early hallmark of cost-optimised baseline PICs and yields approximately 2:1 code density versus typical 8-bit CISC MCUs.
Key features of this PIC16F57 include a 20 MHz internal clock domain (4 MHz instruction rate from a 4x PLL-less divider), 3KB self-programmable Flash, 72 bytes RAM, two 8-bit timer/counters (TMR0, TMR2-class) with one option for a watchdog timer, a programmable code protection scheme, and in-circuit serial programming (ICSP) via dedicated RB6/RB7 pins. The 28-SOIC package offers a 7.50 mm body width (300 mil) for hand-solderable prototype-friendly layouts and is rated -40C to +85C in the industrial -I temperature grade.
Typical applications include low-cost appliance controllers, automotive body and aftermarket modules (pre-CAN era), industrial timers and counters, sensor pre-filters, and small white-goods user-interface boards. The wide 4.5-5.5V supply range tolerates legacy 5V system rails common in industrial PLCs and HVAC controls.
When designing with the PIC16F57, keep in mind that the baseline PIC16F5X instruction set is NOT binary-compatible with mid-range PIC16F1xxx devices and uses a separate toolchain (MPLAB XC8 supports it via the -mcpu=pic16f5x option). Always reserve RB6 and RB7 for ICSP to enable in-field firmware updates without removing the chip.
This page synthesizes distributor pricing, drop-in 28-SOIC alternatives, and practical baseline-PIC design notes not always consolidated on the manufacturer product page.
Drop-in alternatives for PIC16F57-I/SO — 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 PIC16F57-I/SO (same form factor and footprint) — differing in Package, Program Memory Size, Timers, Core Architecture, Program Memory Type.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC16F57-I/P
✅ Drop-In✓ In Stock
$1.18 / Unit
View Datasheet →PIC16F57T-I/SO
✅ Drop-In✓ In Stock
$0.65 / Unit
View Datasheet →PIC16F57-E/SO
✅ Drop-In📋 Reference alternative (not in catalog)
PIC16F59-I/SO
✅ Drop-In📋 Reference alternative (not in catalog)
PIC16F57-I/SP
✅ Drop-In📋 Reference alternative (not in catalog)
PIC16F57-I/SO Maximum Ratings & Electrical Characteristics
| Product Family | PIC16F5X baseline 8-bit |
| Core | PIC16 RISC, 8-bit data path, 12-bit instruction word |
| Program Memory | 3 KB Flash (2K x 12) |
| RAM | 72 bytes |
| Maximum Clock Frequency | 20 MHz |
| Instruction Cycle Time | 200 ns (4x clock) |
| Instruction Set Size | 33 single-word instructions |
| Supply Voltage (Vdd) | 4.5 V to 5.5 V |
| I/O Pins | 20 |
| Timers | TMR0, TMR2-class 8-bit timers; WDT with on-chip oscillator |
| In-Circuit Programming | ICSP via RB6/RB7 |
| Package | 28-pin SOIC (300 mil, 7.50 mm body width) |
| Mounting Type | Surface Mount |
| Operating Temperature | -40 C to +85 C (industrial -I grade) |
| Lead-Free / RoHS | Lead-free; RoHS compliant per Microchip product page |
PIC16F57-I/SO Pin Configuration
| Pin 1 | RA0 — Bidirectional digital I/O, PORTA bit 0 |
| Pin 2 | RA1 — Bidirectional digital I/O, PORTA bit 1 |
| Pin 3 | RA2 — Bidirectional digital I/O, PORTA bit 2 |
| Pin 4 | RA3 — Bidirectional digital I/O, PORTA bit 3 |
| Pin 5 | RA4/T0CKI — Bidirectional digital I/O / Timer0 clock input |
| Pin 6 | RA5 — Bidirectional digital I/O, PORTA bit 5 |
| Pin 7 | RA6 — Bidirectional digital I/O, PORTA bit 6 |
| Pin 8 | RA7 — Bidirectional digital I/O, PORTA bit 7 |
| Pin 9 | OSC1 — Oscillator input / external clock |
| Pin 10 | OSC2 — Oscillator output |
| Pin 11 | RC0 — Bidirectional digital I/O, PORTC bit 0 |
| Pin 12 | RC1 — Bidirectional digital I/O, PORTC bit 1 |
| Pin 13 | RC2 — Bidirectional digital I/O, PORTC bit 2 |
| Pin 14 | VSS — Ground reference |
| Pin 15 | RC3 — Bidirectional digital I/O, PORTC bit 3 |
| Pin 16 | RC4 — Bidirectional digital I/O, PORTC bit 4 |
| Pin 17 | RC5 — Bidirectional digital I/O, PORTC bit 5 |
| Pin 18 | RC6 — Bidirectional digital I/O, PORTC bit 6 |
| Pin 19 | RC7 — Bidirectional digital I/O, PORTC bit 7 |
| Pin 20 | RB0/INT — Bidirectional digital I/O / external interrupt |
| Pin 21 | RB1 — Bidirectional digital I/O, PORTB bit 1 |
| Pin 22 | RB2 — Bidirectional digital I/O, PORTB bit 2 |
| Pin 23 | RB3 — Bidirectional digital I/O, PORTB bit 3 |
| Pin 24 | RB4 — Bidirectional digital I/O, PORTB bit 4 |
| Pin 25 | RB5 — Bidirectional digital I/O, PORTB bit 5 |
| Pin 26 | RB6 — Bidirectional digital I/O / ICSP clock |
| Pin 27 | RB7 — Bidirectional digital I/O / ICSP data |
| Pin 28 | VDD — Positive supply voltage (+5 V nominal) |
Typical Applications
PIC16F57-I/SO is suitable for 6 applications: Low-Cost Appliance Control Board, Industrial 5V Timer / Counter, Automotive Aftermarket Module (Pre-CAN), Sensor Pre-Filter / Debounce Module, HVAC Control Subsystem, Educational Microcontroller Trainer Board.
Low-Cost Appliance Control Board
The PIC16F57-I/SO fits washing-machine and dishwasher user-interface boards because its 20 MHz CPU handles keypad scanning and LED multiplexing well within timing budgets, while 3 KB Flash is sufficient for state-machine firmware without OS overhead. Its 4.5-5.5 V supply matches the 5 V rails on legacy white-goods mainboards, eliminating an LDO. The 28-SOIC package reflow-solders onto automated production lines.
Recommended
Industrial 5V Timer / Counter
For PLC-style 5 V industrial timing modules and machine-timer controllers, PIC16F57-I/SO provides two hardware timers (TMR0 and TMR2-class) and 20 MHz CPU speed adequate for precise interval counting. The 5 V-only supply tolerates the noisy 24 V->5 V DC rails common in factory PLCs. Watchdog timer with on-chip oscillator improves reliability in electrically harsh panels.
Recommended
Automotive Aftermarket Module (Pre-CAN)
The PIC16F57-I/SO suits aftermarket automotive modules such as alarm-trigger units, accessory timers, and relay drivers where its 20 mA I/O source / 25 mA sink can directly drive small automotive relays without external buffers. The 28-SOIC ICSP via RB6/RB7 supports dealer firmware updates. For OEM automotive, prefer PIC16F57-E/SO with the +125 C extended temperature grade.
Recommended
Sensor Pre-Filter / Debounce Module
In sensor-front-end assemblies the PIC16F57-I/SO can sit between mechanical switches / encoders and a host processor, performing software debounce, rate limiting, and simple averaging. The 200 ns instruction cycle polls 20 I/O lines at >10 kHz with headroom, while 3 KB Flash holds multi-channel FSM code. Its 5 V TTL-friendly I/O simplifies wiring to legacy logic.
Recommended
HVAC Control Subsystem
Within HVAC control boards the PIC16F57-I/SO drives triac-firing logic for fan-speed taps and reads thermistor inputs via discrete RC timing. The 20 MHz / 200 ns cycle executes triac zero-cross detection and lookup-table temperature curves in real time. The 5 V supply rails match legacy HVAC mainboards; 28-SOIC survives conformal-coated board washing common in HVAC manufacturing.
Recommended
Educational Microcontroller Trainer Board
Universities and hobbyists use the PIC16F57-I/SO in trainer boards because its 33-instruction baseline PIC16F5X RISC set is small enough for students to master in a single semester. The 28-SOIC reflows onto affordable SMT trainer kits, while RB6/RB7 ICSP lets a PICkit 3/4 program the chip without removing it. MPLAB X IDE + XC8 provides a free toolchain.
Recommended
Recommended Products Summary
Engineering reference data for PIC16F57-I/SO — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16F57-I/P | PIC16F57T-I/SO | PIC16F57-E/SO | PIC16F59-I/SO | PIC16F57-I/SP |
|---|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 28-SOIC (300 mil) | 28-PDIP (through-hole) | 28-SOIC (300 mil) - same | 28-SOIC (300 mil) - same | 28-SOIC (300 mil) - same | 28-PDIP (through-hole) |
| Program Memory (Flash) | 3 KB (2K x 12) | 3 KB | 3 KB | 3 KB | 6 KB (+100%) | 3 KB |
| RAM | 72 bytes | 72 bytes | 72 bytes | 72 bytes | 384 bytes (+433%) | 72 bytes |
| Maximum Clock | 20 MHz | 20 MHz | 20 MHz | 20 MHz | 20 MHz | 20 MHz |
| I/O Pins | 20 | 20 | 20 | 20 | 32 (+60%) | 20 |
| Operating Voltage | 4.5 V to 5.5 V | 4.5 V to 5.5 V | 4.5 V to 5.5 V | 4.5 V to 5.5 V | 4.5 V to 5.5 V | 4.5 V to 5.5 V |
| Temperature Grade | Industrial -40C to +85C | -40C to +85C | -40C to +85C | -40C to +125C (extended) | -40C to +85C | -40C to +85C |
| ICSP | Yes (RB6/RB7) | Yes (RB6/RB7) | Yes (RB6/RB7) | Yes (RB6/RB7) | Yes (RB6/RB7) | Yes (RB6/RB7) |
Key Differentiators
- Lowest-cost baseline PIC in 28-SOIC with full 20 MHz / 3 KB Flash (vs PIC16F59-I/SO)
- Industrial temperature grade -40C to +85C standard (vs PIC16F57-E/SO)
- 5 V native supply - no LDO required (vs PIC16F1xxx mid-range family)
Design Notes
The PIC16F57 belongs to the baseline PIC16F5X family and is NOT instruction-set compatible with mid-range PIC16F1xxx devices. When porting code from PIC16F84/PIC16F628 etc., you must rewrite using the 33-instruction baseline set. In MPLAB X, ensure the build target selects -mcpu=pic16f57 (or legacy HI-TECH PICC pic16f57); wrong target silently produces non-functional binaries.
Reserved pins RB6 and RB7 must remain accessible for ICSP - do not load these pins with heavy capacitance or low-impedance pull-ups that would block the PICkit programmer's drive. Place a 100 nF decoupling capacitor directly between VDD (pin 28) and VSS (pin 14) with traces shorter than 5 mm. Add a bulk 10 uF tantalum near the IC for noisy 5 V industrial rails.
Estimated: at full 20 MHz clock with all 20 I/O pins sourcing 20 mA simultaneously, internal dissipation reaches roughly 400 mW. With the 28-SOIC theta_JA around 70 C/W on a 1 sq-inch copper pour, junction rises approximately 28 C above ambient - safe inside the -40C to +85C industrial window. If driving 10+ LEDs continuously, derate current to 10 mA per pin or distribute loads across ports.
PIC16F57 supply is 4.5 V to 5.5 V - not 3.3 V tolerant. If your system runs a 3.3 V rail, add a level shifter on every I/O pin or select a different MCU. The internal brown-out reset (BOR) is not present on baseline PIC16F5X devices; provide external reset circuitry (RC delay or supervisor IC) if the host 5 V rail has slow rise times exceeding 100 ms.
Compliance Information
RoHS compliant and lead-free per Microchip product page. AEC-Q100 not qualified for OEM automotive - use extended-temp -E/SO only for non-safety-critical aftermarket modules.
