PIC16F818-I/SS - 8-bit 20MHz 1.75KB Flash MCU | Microchip
MPN: PIC16F818-I/SS β Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $2.95 | $2.95 |
| 10 | $2.66 | $26.60 |
| 100 | $2.35 | $235.00 |
| 500 | $2.13 | $1,065.00 |
| 1,000 | $1.92 | $1,920.00 |
PIC16F818-I/SS Overview
An 8-bit microcontroller (MCU) is a single-chip computer that integrates an 8-bit CPU, program memory (ROM/Flash), data memory (RAM), I/O peripherals and a clock source on one silicon die. Within the embedded hierarchy, the PIC16F818 belongs to the PIC16F family of microcontrollers, which sits within Microchip's 8-bit PIC product line, which is itself a category of microcontrollers (MCU), which is a category of embedded processors, which is a category of semiconductors. The PIC16F818 is pin-compatible with the PIC16F819, and is software- and peripheral-compatible with the larger PIC16C7x, PIC16C62xA, PIC16C5X and PIC12CXXX families, giving designers an easy migration path from older OTP or ROM-based parts to Flash-based silicon.
Key features include an internal 8 MHz oscillator (no external crystal required for many designs), 16 I/O pins with individually programmable direction, a 10-bit ADC with up to 5 channels, an enhanced Capture/Compare/PWM (ECCP) module, an MSSP port supporting SPI and I2C (master/slave), an asynchronous USART for RS-232/RS-485, two 8-bit timers plus one 16-bit timer, and a watchdog timer with its own on-chip low-power RC oscillator. The Flash program memory supports in-circuit serial programming (ICSP) via two pins, allowing firmware updates after PCB assembly.
The PIC16F818 operates from 2.0 V to 5.5 V across the industrial -40C to +85C range, suiting it for 3.3 V and 5 V designs. With a typical active current of <2 mA at 4 MHz and 5 V, plus sub-microamp sleep currents with brown-out reset (BOR) enabled, the part targets low-power embedded nodes. The 20-pin SSOP (5.30 mm body) provides a compact 0.65 mm pitch footprint, balancing IO count with board-area efficiency.
Typical applications include consumer appliance control panels, sensor interface nodes, simple LED lighting controllers, low-cost motor control loops, and battery-powered instrument peripherals. For designs needing more memory or a second comparator, designers can drop in the PIC16F819 (2K Flash) without changing the PCB.
When designing with this MCU, reserve the ICSPDAT/ICSPCLK pins (typically RB7/RB6) so that in-circuit programming remains possible in production. Place a 100 nF decoupling capacitor within 5 mm of VDD, and a bulk 10 uF if the application drives heavy loads from the same rail. Verify MCLR behaviour - the device ships with MCLR disabled; an external pull-up or dedicated reset circuit may be required.
This page synthesizes distributor pricing, drop-in alternatives, and practical design notes not found in the manufacturer datasheet.
Drop-in alternatives for PIC16F818-I/SS β 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 PIC16F818-I/SS (same form factor and footprint) β differing in Timers, ADC, Package, Core Architecture, I/O Pins.
Quick Comparison Tool β Select alternative parts for side-by-side comparison:
PIC16F819-I/SS
β Drop-Inβ In Stock
$2.11 / Unit
View Datasheet βPIC16F88-I/SS
β Drop-Inπ Reference alternative (not in catalog)
PIC16F818-E/SS
β Drop-Inπ Reference alternative (not in catalog)
PIC16LF818-I/SS
β Drop-Inπ Reference alternative (not in catalog)
PIC16F76-I/SS
β Drop-Inβ In Stock
$5.45 / Unit
View Datasheet βPIC16F767-I/SS
β Drop-Inβ In Stock
$2.18 / Unit
View Datasheet βPIC16F818-I/SS Maximum Ratings & Electrical Characteristics
| Core Architecture | PIC16 (8-bit RISC) |
| Program Memory | 1.75 KB Flash (1K x 14 words) |
| Data SRAM | 128 B |
| Data EEPROM | 128 B |
| Maximum CPU Frequency | 20 MHz |
| Instruction Cycle | 200 ns at 20 MHz |
| I/O Pins | 16 |
| Supply Voltage (VDD) | 2.0 V to 5.5 V |
| ADC | 10-bit, up to 5 channels |
| Timers | Two 8-bit, one 16-bit |
| Communication | MSSP (SPI / I2C), USART (RS-232/RS-485) |
| PWM | Enhanced CCP (ECCP) module |
| Internal Oscillator | 8 MHz |
| Operating Temperature | -40C to +85C (Industrial) |
| Package | 20-pin SSOP |
| Mounting Type | Surface Mount |
| RoHS Status | Compliant |
| ICSP | Yes (in-circuit serial programming) |
| Brown-out Reset | Yes |
| Watchdog Timer | Yes, with dedicated RC oscillator |
PIC16F818-I/SS Pin Configuration
| Pin 1 | RA0/AN0 β Digital I/O / Analog input channel 0 |
| Pin 2 | RA1/AN1 β Digital I/O / Analog input channel 1 |
| Pin 3 | RA2/AN2/VREF- β Digital I/O / Analog input / ADC negative reference |
| Pin 4 | RA3/AN3/VREF+ β Digital I/O / Analog input / ADC positive reference |
| Pin 5 | RA4/T0CKI β Digital I/O / Timer 0 clock input (open-drain) |
| Pin 6 | RA5/AN4/SS β Digital I/O / Analog input / SPI slave select |
| Pin 7 | VSS β Ground reference |
| Pin 8 | OSC1/CLKIN β Crystal oscillator input / external clock input |
| Pin 9 | OSC2/CLKOUT β Crystal oscillator output / clock output |
| Pin 10 | RC0/T1OSO/T1CKI β Digital I/O / Timer 1 oscillator output / clock input |
| Pin 11 | RC1/T1OSI/CCP2 β Digital I/O / Timer 1 oscillator input / CCP2 output |
| Pin 12 | RC2/CCP1 β Digital I/O / Enhanced CCP1 PWM output |
| Pin 13 | RC3/SCK/SCL β Digital I/O / SPI clock / I2C clock |
| Pin 14 | RC4/SDI/SDA β Digital I/O / SPI data in / I2C data |
| Pin 15 | RC5/SDO β Digital I/O / SPI data out |
| Pin 16 | RC6/TX/CK β Digital I/O / USART TX / USART clock |
| Pin 17 | RC7/RX/DT β Digital I/O / USART RX / USART data |
| Pin 18 | VDD β Positive supply voltage |
| Pin 19 | RB0/INT β Digital I/O / External interrupt |
| Pin 20 | RB1/RX/DT β Digital I/O / USART RX (alternate) |
Typical Applications
PIC16F818-I/SS is suitable for 6 applications: Consumer Appliance Control Panels, Battery-Powered Sensor Interface Nodes, Low-Cost Motor Control Loops, Simple LED Lighting Controllers, Industrial Sensor Signal Conditioning, Educational and Hobby Electronics.
Consumer Appliance Control Panels
The PIC16F818-I/SS fits consumer appliance control panels because its 16 digital I/O pins, USART for display communication, and ECCP PWM for LED or buzzer drive integrate the entire UI logic in one chip. At typical 4 MHz operation from a 5 V rail, current draw is under 2 mA, so a small linear regulator can power the entire board. The 20-pin SSOP package fits behind membrane switch panels in washing machines and microwave ovens. Use the 10-bit ADC to read keypad resistance ladders and the MSSP to drive character LCDs or LED matrices.
Recommended
Battery-Powered Sensor Interface Nodes
The PIC16F818-I/SS suits battery-powered sensor interface nodes where sub-microamp sleep current and 128-byte EEPROM for calibration constants are mandatory. The internal 8 MHz oscillator eliminates external crystal draw, and the 10-bit ADC with 5 channels handles temperature, humidity, or voltage sensing without a separate front-end. Wake from sleep on a pin change, sample the sensor, push data over I2C, and return to sleep for multi-year coin-cell operation. Its -40C to +85C industrial range covers outdoor IoT deployments.
Recommended
Low-Cost Motor Control Loops
The PIC16F818-I/SS controls small brushed DC or low-power stepper motors via its enhanced CCP module, which delivers PWM at up to 10-bit resolution with hardware dead-band control. The 16-bit timer captures encoder feedback for closed-loop speed regulation. With 1.75 KB Flash and 128-byte SRAM, firmware can hold a PID loop, lookup tables for acceleration ramps, and a UART command parser for remote motor control. The 20-pin SSOP keeps board size small for hobby robotics and small appliance pumps.
Recommended
Simple LED Lighting Controllers
The PIC16F818-I/SS drives RGB LED strips and dimmable fixtures using its ECCP PWM output for high-frequency dimming up to 20 kHz above the audible band. The MSSP in I2C mode interfaces with digital color sensors or external EEPROM storing scene presets. With 128 bytes of EEPROM, the controller retains last-on state across power cycles without external FRAM. Operating from 2.0 V to 5.5 V, it works in both 3.3 V and 5 V lighting designs without level shifters.
Recommended
Industrial Sensor Signal Conditioning
The PIC16F818-I/SS conditions and digitizes industrial sensor signals using its 10-bit ADC for analog front-end, USART for digital output to PLCs or displays, and SPI MSSP for high-speed sensor communication. Its industrial -40C to +85C temperature range tolerates factory floor environments. Combined with the brown-out reset and watchdog timer, it provides reliable operation in noisy industrial settings. The SSOP-20 package supports compact DIN-rail modules and instrumentation panels.
Recommended
Educational and Hobby Electronics
The PIC16F818-I/SS is popular in educational and hobby electronics due to its low cost (under USD 2 in qty-1000), simple PIC16 instruction set with only 35 single-word instructions, and free Microchip MPLAB X IDE support. Its in-circuit serial programming (ICSP) interface via RB6/RB7 means students can reprogram the chip repeatedly without removing it from the breadboard. Combined with the 16 I/O pins and built-in USART, it teaches embedded basics like ADC reading, PWM generation, and serial communication.
Recommended
Recommended Products Summary
Engineering reference data for PIC16F818-I/SS β comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16F819-I/SS | PIC16F88-I/SS | PIC16F818-E/SS | PIC16LF818-I/SS |
|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | SSOP-20 | SSOP-20 - same | SSOP-20 - same | SSOP-20 - same | SSOP-20 - same |
| Program Flash Memory | 1.75 KB (1K x 14) | 3.5 KB (2K x 14) | 7 KB (4K x 14) | 1.75 KB (1K x 14) | 1.75 KB (1K x 14) |
| Maximum CPU Frequency | 20 MHz | 20 MHz | 20 MHz | 20 MHz | 20 MHz |
| Supply Voltage Range | 2.0 V to 5.5 V | 2.0 V to 5.5 V | 2.0 V to 5.5 V | 2.0 V to 5.5 V | 1.8 V to 3.6 V (low-voltage) |
| Operating Temperature Range | -40C to +85C (Industrial) | -40C to +85C | -40C to +85C | -40C to +125C (Extended) | -40C to +85C |
| Analog Comparators | 0 (only ADC) | 2 | 2 | 0 | 0 |
| Internal Voltage Reference | No | No | Yes | No | No |
| I/O Pins | 16 | 16 | 16 | 16 | 16 |
Key Differentiators
- Lowest-cost 20-MHz Flash PIC16 MCU in SSOP-20 from Microchip (vs PIC16F88-I/SS)
- Pin-compatible upgrade path to PIC16F819-I/SS doubles Flash without PCB changes (vs PIC16F819-I/SS)
- Available in extended -40C to +125C variant for harsh environments (vs PIC16F818-E/SS)
Design Notes
Place a 100 nF decoupling capacitor within 5 mm of the VDD pin (pin 18) and a 10 uF bulk capacitor on the same rail for designs that source significant current from the MCU's I/O pins. For battery-powered designs, leverage the PIC16F818-I/SS's sub-microamp sleep mode and configure brown-out reset (BOR) to a low threshold (2.0 V) to maximize usable battery capacity. Avoid enabling BOR at high voltage on coin-cell cells; the internal reference draw can shorten battery life.
Reserve pins RB6 and RB7 (ICSPDAT and ICSPCLK) on the PCB layout so that in-circuit serial programming remains possible in production. If these pins must be used for other functions, route them through test points or 0-ohm jumpers so they can be isolated during programming. Keep the ICSP connector within 50 mm of the MCU to avoid signal-integrity issues on the programming lines. Add a 4.7 kohm pull-up to MCLR if MCLR is enabled in configuration bits.
The PIC16F818-I/SS ships with MCLR disabled by configuration fuses - if external reset is required, the configuration bit must be explicitly set to enable MCLR, and an external RC reset network added. The 10-bit ADC requires the ADCON1 register to be configured to select which pins are analog versus digital; failing to do so can cause ADC readings to float or pins to behave erratically. Always validate the oscillator configuration bits before locking the code, since selecting the wrong mode can prevent the part from starting.
When using the MSSP in SPI mode at high speeds (above 4 MHz), keep SCK trace length under 50 mm and add a 33 ohm series damping resistor near the source. For I2C, the PIC16F818-I/SS's SDA and SCL are open-drain and require external 4.7 kohm pull-ups to VDD; do not rely on internal weak pull-ups for bus speeds above 100 kHz. The USART pins (RC6/RC7) should be series-terminated with 100 ohm resistors if driving cables longer than 100 mm.
Compliance Information
RoHS compliant per Newark distributor listing. Lead-free SSOP-20 package. Not AEC-Q100 qualified; for automotive applications, contact Microchip about PIC16F818-E/SS extended temperature variants or PIC16F88-I/SS automotive grades.
