PIC16F18857-I/SO - 56KB Flash 32MHz 8-bit MCU | Microchip
MPN: PIC16F18857-I/SO ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $2.62 | $2.62 |
| 10 | $2.41 | $24.10 |
| 100 | $2.15 | $215.00 |
| 500 | $1.92 | $960.00 |
| 1,000 | $1.7 | $1,700.00 |
| 3,000 | $1.42 | $4,260.00 |
PIC16F18857-I/SO Overview
An 8-bit microcontroller (MCU) is a single-chip computer that integrates a CPU core, Flash program memory, SRAM, EEPROM, and peripherals on one die. The PIC architecture is a RISC (Reduced Instruction Set Computer) core that executes most instructions in a single clock cycle, making it deterministic and easy to use in real-time control. MCUs sit at the top of the embedded computing hierarchy: MCU -> embedded controller -> embedded system, and are used wherever low-cost programmable logic is required.
Key features of the PIC16F18857-I/SO include 24-channel 10-bit ADC with automatic acquisition, up to 17 PWM channels for motor and lighting control, multiple I2C/SPI/EUSART peripherals for sensor and bus connectivity, 256B EEPROM for non-volatile user data, and Hardware Limit Timer (HLT), CRC/SCAN, and Windowed Watchdog Timer for functional safety applications. The XLP technology provides nanoWatt sleep currents for battery-powered designs.
The PIC16F18857-I/SO operates from 2.3V to 5.5V with industrial temperature range of -40C to +85C and supports in-circuit serial programming (ICSP) via two pins. The 28-SOIC wide package supports hand-soldering and is compatible with standard 0.1-inch wide SOIC land patterns.
Typical applications include industrial sensor interfaces, low-power IoT nodes, consumer appliance control, lighting controllers, automotive body electronics, and any battery-operated device requiring XLP sleep modes. The peripheral-rich architecture supports standalone designs with minimal external components.
Designers should connect decoupling capacitors (typically 100 nF and 10 uF) close to VDD, configure the unused I/O pins as outputs and tie MCLR through a 10 kOhm resistor to VDD for reliable operation, and follow Microchip's TB3079 guidelines for PCB layout of PIC microcontrollers.
This page synthesizes distributor pricing, drop-in same-family alternatives, and practical design notes not found in the manufacturer datasheet.
Drop-in alternatives for PIC16F18857-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 PIC16F18857-I/SO (same form factor and footprint) — differing in ADC, Package, Family, Core Architecture, Operating Temperature.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC16F18856-I/SO
✅ Drop-In📋 Reference alternative (not in catalog)
PIC16F18855-I/SO
✅ Drop-In✓ In Stock
$1.29 / Unit
View Datasheet →PIC16F18854-I/SO
✅ Drop-In✓ In Stock
$0.82 / Unit
View Datasheet →PIC16F18857-I/SP
✅ Drop-In✓ In Stock
$1.89 / Unit
View Datasheet →PIC16F18857-I/ML
✅ Drop-In✓ In Stock
$1.8 / Unit
View Datasheet →PIC16LF18857-I/SO
✅ Drop-In✓ In Stock
$1.95 / Unit
View Datasheet →PIC16F18857-I/SO Maximum Ratings & Electrical Characteristics
| Core Architecture | PIC RISC 8-bit |
| Family | PIC16F1885X/7X (XLP, Functional Safety) |
| Program Memory (Flash) | 56 KB (32K x 14 words) |
| SRAM | 4 KB |
| EEPROM | 256 B |
| Maximum CPU Speed | 32 MHz |
| Operating Voltage Range | 2.3 V to 5.5 V |
| ADC | 10-bit, up to 24 channels |
| Communication Peripherals | I2C, SPI, EUSART (UART) |
| PWM Channels | Up to 17 |
| Operating Temperature Range | -40 C to +85 C (Industrial) |
| Package | 28-pin SOIC wide (7.50 mm body) |
| Mounting Type | Surface Mount |
| MSL Level | 1 (unlimited floor life at <30 C / 85% RH) |
| Lead-Free / RoHS | Lead-free, RoHS compliant |
| Programming | ICSP (In-Circuit Serial Programming) via 2 pins |
| Functional Safety | FuSa features: CRC/SCAN, HLT, Windowed WDT |
PIC16F18857-I/SO Pin Configuration
| Pin 1 | RA2 — Bidirectional I/O / analog channel |
| Pin 2 | RA3 — Bidirectional I/O / analog channel |
| Pin 3 | RA4 — Bidirectional I/O / analog channel |
| Pin 4 | RA5 — Bidirectional I/O / analog channel |
| Pin 5 | RA6 — Bidirectional I/O |
| Pin 6 | RA7 — Bidirectional I/O |
| Pin 7 | VSS — Ground reference |
| Pin 8 | VDD — Positive supply (2.3-5.5 V) |
| Pin 9 | OSC1/CLKI/RA0 — External clock input / I/O |
| Pin 10 | OSC2/CLKO/RA1 — Crystal output / I/O |
| Pin 11 | RC0 — Bidirectional I/O |
| Pin 12 | RC1 — Bidirectional I/O |
| Pin 13 | RC2 — Bidirectional I/O |
| Pin 14 | RC3 — Bidirectional I/O |
| Pin 15 | RC4 — Bidirectional I/O |
| Pin 16 | RC5 — Bidirectional I/O |
| Pin 17 | RC6 — Bidirectional I/O |
| Pin 18 | RC7 — Bidirectional I/O |
| Pin 19 | VSS — Ground reference |
| Pin 20 | VDD — Positive supply (2.3-5.5 V) |
| Pin 21 | RB0 — Bidirectional I/O / interrupt-on-change |
| Pin 22 | RB1 — Bidirectional I/O / interrupt-on-change |
| Pin 23 | RB2 — Bidirectional I/O / interrupt-on-change |
| Pin 24 | RB3 — Bidirectional I/O / interrupt-on-change |
| Pin 25 | RB4 — Bidirectional I/O / interrupt-on-change |
| Pin 26 | RB5 — Bidirectional I/O / interrupt-on-change |
| Pin 27 | RB6/ICSPCLK — Bidirectional I/O / ICSP clock |
| Pin 28 | RB7/ICSPDAT — Bidirectional I/O / ICSP data |
Typical Applications
PIC16F18857-I/SO is suitable for 7 applications: Industrial Sensor Interface, Battery-Operated IoT Edge Node, Lighting and PWM Control, Consumer Appliance Control, Automotive Body Electronics, Medical Monitoring Devices, Smart Home Sensor Hubs.
Industrial Sensor Interface
The PIC16F18857-I/SO fits industrial sensor interfaces because it integrates a 24-channel 10-bit ADC, multiple I2C/SPI peripherals, and the Functional Safety block set required by IEC 61508 SIL-2 designs. Placed on a 4-20 mA loop transmitter PCB or a multi-sensor hub, it digitizes analog signals and forwards them to a host PLC over UART or RS-485. With 56 KB Flash it comfortably hosts Modbus/RTU stacks plus custom DSP routines, while XLP sleep below 50 nA suits 4-20 mA loop-powered applications that must idle for years. The 32 MIPS core handles filter math without external ASICs.
Recommended
Battery-Operated IoT Edge Node
The PIC16F18857-I/SO suits battery-operated IoT edge nodes thanks to its XLP sleep current below 50 nA and 32 MHz execution headroom for sensor pre-processing. On a coin-cell or 2x AA powered wireless sensor PCB, the MCU wakes on timer interrupt, executes sampling/aggregation firmware from 56 KB Flash, transmits via SPI-connected radio, and returns to sleep. Its 256-byte EEPROM stores calibration constants without external memory, reducing BOM cost and quiescent draw. Designers can sleep for years between user events while still supporting field firmware updates via ICSP.
Recommended
Lighting and PWM Control
The PIC16F18857-I/SO is well-suited for LED lighting controllers because it integrates up to 17 PWM channels with hardware limit timer (HLT) and complementary outputs for half-bridge drivers. In a DMX or DALI-controlled architectural luminaire, the MCU parses control frames over UART/SPI, applies dimming curves in firmware, and drives high-current MOSFETs via PWM. Its 5V tolerance eliminates level shifters on legacy LED driver boards, while 56 KB Flash hosts rich dimming and color-mixing firmware. The CRC/SCAN block supports functional-safety-certified luminaires per IEC 61508.
Recommended
Consumer Appliance Control
The PIC16F18857-I/SO is ideal for consumer appliance main boards in washing machines, dishwashers, and air conditioners where it must handle keypad scanning, LCD drive, and motor control on a single chip. With 4 KB SRAM and 32 MIPS throughput it comfortably runs a small RTOS or state-machine UI loop. The 10-bit ADC monitors motor current and supply rails while multiple PWMs drive triac-firing or DC-brushless motors. Industrial -40 to +85 C temperature rating suits unconditioned cabinet environments near motors and heaters.
Recommended
Automotive Body Electronics
The PIC16F18857-I/SO fits automotive body-electronics modules (BCM, seat controllers, mirror actuators) where Functional Safety and -40 to +125 C qualified variants exist in the same die family. With LIN-compatible EUSART and CAN-friendly timer blocks, the MCU bridges LIN subnets and drives relay/LED loads via PWMs. The CRC/SCAN block detects Flash bit errors for ASIL-aware software, and 56 KB Flash hosts the body-control state machine plus diagnostics. The 28-SOIC package supports hand-prototyping and high-volume automated SMT lines alike.
Recommended
Medical Monitoring Devices
The PIC16F18857-I/SO supports portable medical monitoring devices (pulse oximeters, glucometers, smart thermometers) where XLP sleep, ADC precision, and deterministic real-time response are critical. Running at 32 MHz it samples photodiode or thermistor arrays through its 10-bit ADC at rates sufficient for SpO2 calculation, then enters deep sleep between measurements to extend battery life. The 256-byte EEPROM stores patient profiles and calibration constants securely, while the CRC/SCAN block supports IEC 62304/ISO 13485 quality processes for low-risk medical devices.
Recommended
Smart Home Sensor Hubs
The PIC16F18857-I/SO anchors smart-home sensor hubs that aggregate multiple I2C sensors (temperature, humidity, air-quality, motion) and report over Wi-Fi or Thread. With 56 KB Flash and 4 KB SRAM it runs an event-driven scheduler, while its XLP sleep allows battery-powered window/door sensors to last several years. The 17 PWMs and 24 ADC channels let designers integrate RGB indicator LEDs and analog knob inputs on the same hub PCB. ICSP enables field firmware updates over the air through a co-resident radio module.
Recommended
Recommended Products Summary
Engineering reference data for PIC16F18857-I/SO — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16F18856-I/SO | PIC16F18855-I/SO | PIC16F18854-I/SO | PIC16F18857-I/SP | PIC16F18857-I/ML | PIC16LF18857-I/SO |
|---|---|---|---|---|---|---|---|
| Package | 28-SOIC wide | 28-SOIC wide - same | 28-SOIC wide - same | 28-SOIC wide - same | 28-SPDIP - same pinout, through-hole | 28-QFN - same pinout, SMD smaller | 28-SOIC wide - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Flash Program Memory | 56 KB | 28 KB | 32 KB | 16 KB | 56 KB | 56 KB | 56 KB |
| SRAM | 4 KB | 2 KB | 2 KB | 1 KB | 4 KB | 4 KB | 4 KB |
| EEPROM | 256 B | 256 B | 256 B | 256 B | 256 B | 256 B | 256 B |
| Maximum CPU Speed | 32 MHz | 32 MHz | 32 MHz | 32 MHz | 32 MHz | 32 MHz | 32 MHz |
| Operating Voltage Range | 2.3 V to 5.5 V | 2.3 V to 5.5 V | 2.3 V to 5.5 V | 2.3 V to 5.5 V | 2.3 V to 5.5 V | 2.3 V to 5.5 V | 1.8 V to 3.6 V |
| ADC Resolution / Channels | 10-bit / up to 24 channels | 10-bit / up to 24 channels | 10-bit / up to 24 channels | 10-bit / up to 24 channels | 10-bit / up to 24 channels | 10-bit / up to 24 channels | 10-bit / up to 24 channels |
Key Differentiators
- Largest Flash and SRAM in the 28-SOIC PIC16F1885X/7X family (vs PIC16F18855-I/SO)
- Functional Safety (FuSa) hardware block set for IEC 61508 (vs PIC16F18854-I/SO)
- Same die across SOIC, SPDIP and QFN packages (vs PIC16F18857-I/ML (QFN))
- Wide 2.3-5.5 V supply for 3.3 V and 5 V designs (vs PIC16LF18857-I/SO)
Design Notes
Place a 100 nF X7R ceramic decoupling capacitor within 5 mm of each VDD pin (pins 8 and 20 on the 28-SOIC), and a 10 uF bulk capacitor on the main supply rail. The PIC16F18857's wide 2.3-5.5 V input allows direct connection to 3.3 V or 5 V rails, but noisy motor or relay supplies benefit from a ferrite bead plus the LDO recommended by Microchip TB3079. Estimated: with a 32 MHz clock at 5 V, core current is around 7 mA and I/O current scales with load.
Route the ICSP clock (RB6) and data (RB7) traces as short, parallel pairs with no adjacent high-speed signals to avoid programming failures. Place the MCLR pull-up (typically 10 kOhm to VDD) close to the pin and avoid long parallel runs near switching converters. Estimated: trace capacitance above 30 pF can cause ICSP timing failures during programming with low-cost debug tools.
Always configure unused I/O pins as outputs and drive them to a defined logic level (low to minimize current) - floating inputs can toggle into the middle threshold and source/sink milliamps into the input structure. Do not leave MCLR floating; either tie to VDD through a 10 kOhm resistor or drive it directly from the programmer. Failure to disable the watchdog timer in low-power sleep will cause unintended resets.
Estimated: at 32 MHz, 5 V operation, the PIC16F18857-I/SO draws around 7-10 mA from VDD, yielding 35-50 mW of internal dissipation. The 28-SOIC package has a typical theta_JA around 70 C/W on a 2-layer FR-4 board, so the junction rises only 3-4 C above ambient - well within the 85 C industrial rating without a heatsink. Above 32 MHz in hot enclosures, add thermal vias and a copper pour to improve dissipation.
Keep the analog AVdd/AVss pair (or the digital VDD/VSS pair supplying the ADC) routed symmetrically to maintain reference integrity. Place the analog reference decoupling capacitor (typically 100 nF) at the MCU pin before any series resistance. Estimated: a poorly placed 10 kOhm analog source impedance combined with stray capacitance can degrade 10-bit ADC linearity by 1-2 LSB at full sampling rate.
Compliance Information
RoHS and lead-free confirmed by DigiKey and Mouser distributor listings. Industrial -40 to +85 C operating range; AEC-Q100 grade parts exist in the same die family but the I/SO variant itself is not AEC-Q100 qualified. Manufacturer Functional Safety documentation supports IEC 61508 SIL-2 capability per PIC16F FuSa family manuals.
