PIC16F685-I/P - 8-Bit 20MHz 7KB Flash MCU 18 I/O DIP-20 | Microchip
MPN: PIC16F685-I/P ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $2.34 | $2.34 |
| 10 | $2.1 | $21.00 |
| 100 | $1.82 | $182.00 |
| 500 | $1.55 | $775.00 |
| 1,000 | $1.32 | $1,320.00 |
PIC16F685-I/P Overview
A microcontroller (MCU) is a single-chip computer that integrates a CPU core, program and data memory, and peripheral interfaces into one IC. The PIC16F685 belongs to the mid-range 8-bit PIC16F family, which sits beneath the PIC18 and dsPIC/PIC24 families in Microchip's 8-bit and 16-bit taxonomy. Within the broader semiconductor hierarchy, it is part of the embedded processor / microcontroller category, designed for deterministic real-time control rather than application processing.
The PIC16F685 family uses Microchip's enhanced mid-range x14 instruction set with only 35 single-word instructions, simplifying code development and reducing compiler overhead. Its nanoWatt power-management features include multiple idle and sleep modes, switchable oscillator sources, and peripheral disable controls that drop the typical supply current well below 1 µA in sleep, making the part suitable for battery-powered designs.
Typical applications include white goods and small appliance control, LED lighting drivers, simple sensor signal conditioning, consumer electronics user interfaces, automotive body modules (non-safety), and battery-powered instrumentation where low quiescent current and integrated peripherals reduce BOM cost.
Designers should plan the oscillator configuration carefully because the internal 8 MHz HFINTOSC can drift; selecting the 31 kHz LFINTOSC for sleep wake-ups saves power. The ICSPDAT/ICSPCLK pins must be accessible for in-circuit programming and debugging, so pin assignment should reserve them early in PCB layout.
The -I suffix indicates the industrial temperature grade (-40 °C to +85 °C); the -E (extended) variant is available for -40 °C to +125 °C operation. The -P suffix denotes the 20-pin PDIP through-hole package, the easiest variant for prototyping and hobbyist use.
This page synthesizes distributor pricing, drop-in PIC16F685-I/P alternatives, parametric comparison, and practical design notes that go beyond the manufacturer datasheet summary.
Drop-in alternatives for PIC16F685-I/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 PIC16F685-I/P (same form factor and footprint) — differing in Package, Mounting Type, Operating Temperature, Timers, A/D Converter.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC16F687-I/P
✅ Drop-In📋 Reference alternative (not in catalog)
PIC16F689-I/P
✅ Drop-In✓ In Stock
$1.82 / Unit
View Datasheet →PIC16F690-I/P
✅ Drop-In✓ In Stock
$1.89 / Unit
View Datasheet →PIC16F677-I/P
✅ Drop-In📋 Reference alternative (not in catalog)
PIC16F685-E/SO
✅ Drop-In✓ In Stock
$1.85 / Unit
View Datasheet →PIC16F685-I/P Maximum Ratings & Electrical Characteristics
| Core | PIC16F mid-range 8-bit (enhanced x14) |
| Instruction Set | 35 single-word instructions, 14-bit wide |
| Max CPU Speed | 20 MHz (200 ns instruction cycle) |
| Program Memory (Flash) | 7 KB (4K x 14 words) |
| Data SRAM | 256 bytes |
| Data EEPROM | 256 bytes |
| General-Purpose I/O | 18 |
| Operating Voltage (VDD) | 2.0 V to 5.5 V |
| Operating Temperature | -40 °C to +85 °C (industrial, -I) |
| Package | 20-pin PDIP (DIP-20, 0.300 in / 7.62 mm) |
| Mounting Type | Through-hole (THT) |
| A/D Converter | 12 channels, 10-bit |
| Comparators | 2 on-chip |
| PWM Modules | ECCP + 2 CCP (Capture/Compare/PWM) |
| UART | 1 x Enhanced USART (EUSART) |
| Timers | Timer0, Timer1, Timer2 (8/16-bit) |
| Watchdog Timer | Yes (WDT, software-enabled) |
| Brown-out Reset / POR | Yes |
| In-Circuit Programming | ICSP (2-wire) |
| Power-Saving Modes | nanoWatt technology: Sleep, Idle, low-power T1 osc |
| RoHS / Lead-Free | Compliant / lead-free per Microchip product page |
PIC16F685-I/P Pin Configuration
| Pin 1 | VDD — Positive supply voltage (2.0 V to 5.5 V) |
| Pin 2 | RA5/SS/HLVDIN — Bidirectional I/O; SPI slave select; high/low-voltage detect input |
| Pin 3 | RA4/AN3/T1G/OSC2/CLKOUT — Bidirectional I/O; analog input; Timer1 gate; oscillator output |
| Pin 4 | RA3/AN2/C1OUT — Bidirectional I/O; analog input; comparator 1 output |
| Pin 5 | RA2/AN1/C2OUT — Bidirectional I/O; analog input; comparator 2 output |
| Pin 6 | RA1/AN0/C12IN0- — Bidirectional I/O; analog input; comparator reference |
| Pin 7 | RA0/AN0+/C12IN0+ — Bidirectional I/O; analog input; comparator non-inverting input |
| Pin 8 | VSS — Ground reference |
| Pin 9 | RA7/OSC1/CLKIN — Bidirectional I/O; crystal oscillator input or external clock |
| Pin 10 | RA6/OSC2/CLKOUT — Bidirectional I/O; crystal oscillator output |
| Pin 11 | RC0 — Bidirectional I/O |
| Pin 12 | RC1 — Bidirectional I/O |
| Pin 13 | RC2/CCP1 — Bidirectional I/O; Capture/Compare/PWM 1 |
| Pin 14 | RC3 — Bidirectional I/O |
| Pin 15 | RC4 — Bidirectional I/O |
| Pin 16 | RC5 — Bidirectional I/O |
| Pin 17 | RC6/AN8/SS — Bidirectional I/O; analog input; SPI slave select |
| Pin 18 | RC7/AN9/SDO — Bidirectional I/O; analog input; SPI data out |
| Pin 19 | VSS — Ground reference |
| Pin 20 | VDD — Positive supply voltage (2.0 V to 5.5 V) |
Typical Applications
PIC16F685-I/P is suitable for 6 applications: White Goods / Home Appliance Control, LED Lighting Drivers and Dimmers, Battery-Powered Sensor / IoT Edge Nodes, Industrial Control and Process Monitoring, Automotive Body and Interior Modules, Consumer Electronics User Interfaces.
White Goods / Home Appliance Control
The PIC16F685-I/P is well suited for white goods controllers in washing machines, dishwashers, and microwave ovens. Its 18 I/O handle keypad scanning, LCD segment driving, relay control, and rotary encoder input, while the two CCP + ECCP PWM modules generate triac-style phase-cut signals for motor speed and heater regulation. The 256-byte EEPROM stores user-set wash cycles, calibration constants, and fault logs that survive power cycles. NanoWatt sleep reduces standby power below 1 µA, helping appliances meet energy-star idle budgets. Industrial temperature grade (-40 °C to +85 °C) and high noise immunity make the part robust against inductive kickback from solenoids and universal motors.
Recommended
LED Lighting Drivers and Dimmers
Constant-current LED drivers and dimmers benefit from the PIC16F685-I/P's ECCP module, which provides PWM with auto-shutdown, dead-band control, and 10-bit resolution for flicker-free dimming down to 1 %. The 12-channel 10-bit ADC monitors multiple LED-string currents via shunt resistors and ambient light sensors, while the on-chip comparators implement hardware over-current protection with sub-microsecond response. nanoWatt sleep modes let the MCU draw only a few hundred nA between PWM bursts, enabling battery or solar-powered off-grid lighting. Wide 2.0-5.5 V operation supports direct connection to 3.3 V logic-level LED drivers and 5 V boost-converter outputs.
Recommended
Battery-Powered Sensor / IoT Edge Nodes
The PIC16F685-I/P's nanoWatt technology makes it a strong choice for battery-powered environmental sensors, security PIR nodes, and simple IoT edge devices. Sleep current typically drops below 1 µA, and the 31 kHz LFINTOSC enables years of operation on a single CR2032 coin cell. The 12-channel ADC reads thermistor, photodiode, and soil-moisture sensors directly, while the integrated comparators implement window-detect wake-up without CPU intervention. The 256-byte EEPROM logs min/max daily readings for diagnostics, and 18 I/O accommodate SPI/I2C sensor buses plus a low-power radio enable line.
Recommended
Industrial Control and Process Monitoring
In industrial panels and small PLC I/O modules, the PIC16F685-I/P digitizes 4-20 mA loops, drives 24 V optocoupler interfaces, and implements Modbus RTU over its EUSART at 9600-115200 baud. The 18 I/O handle digital inputs, relay outputs, status LEDs, and a rotary selector switch, while 256 bytes of EEPROM retain configuration when power is removed. Brown-out reset and the wide 2.0-5.5 V supply tolerate noisy 24 V backplane rails after regulation. The industrial -40 °C to +85 °C temperature grade covers unconditioned cabinet environments.
Recommended
Automotive Body and Interior Modules
Within automotive body electronics (non-safety), the PIC16F685-I/P drives interior lighting, mirror adjust, seat-position memory, and accessory control. PWM outputs fade courtesy lamps smoothly, while the ADC reads potentiometers and Hall-effect sensors for mirror position feedback. EEPROM stores user presets across battery disconnects. Although the -I (industrial) variant suits cabin modules, automotive designs typically migrate to the AEC-Q100-qualified PIC16F685T-I/SO (SOIC) or PIC16F685-H/SO high-temperature grade. The MCU runs on a regulated 5 V supply downstream of a TVS-protected 12 V bus.
Recommended
Consumer Electronics User Interfaces
The PIC16F685-I/P serves as a low-cost user-interface controller for coffee machines, air purifiers, smart speakers (auxiliary), and small appliances with capacitive or matrix keypads. Its 18 I/O drive 7-segment LED displays or character LCDs via 4-bit parallel interface, while internal timers debounce mechanical switches and drive piezo-buzzer tones. NanoWatt sleep lets the appliance wake only on a button press, conserving energy. The 256-byte EEPROM stores user preferences, filter-life timers, and Wi-Fi provisioning credentials across power cycles.
Recommended
Recommended Products Summary
Engineering reference data for PIC16F685-I/P — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16F687-I/P | PIC16F689-I/P | PIC16F690-I/P | PIC16F677-I/P | PIC16F685-E/SO |
|---|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | PDIP-20 (THT) | PDIP-20 (THT) - same | PDIP-20 (THT) - same | PDIP-20 (THT) - same | PDIP-20 (THT) - same | SOIC-20 (SMT, extended temp) |
| Program Memory (Flash) | 7 KB | 7 KB | 7 KB | 7 KB | 3.5 KB (-50%) | 7 KB |
| Data SRAM | 256 B | 256 B | 256 B | 256 B | 128 B (-50%) | 256 B |
| I/O Pins | 18 | 18 | 18 | 18 | 14 (-22%) | 18 |
| Operating Voltage | 2.0-5.5 V | 2.0-5.5 V | 2.0-5.5 V | 2.0-5.5 V | 2.0-5.5 V | 2.0-5.5 V |
| Operating Temperature | -40 to +85 °C | -40 to +85 °C | -40 to +85 °C | -40 to +85 °C | -40 to +85 °C | -40 to +125 °C |
| PWM Channels | 3 (1 ECCP + 2 CCP) | 3 (1 ECCP + 2 CCP) | 3 (1 ECCP + 2 CCP) | 3 (1 ECCP + 2 CCP) | 2 (1 ECCP + 1 CCP) | 3 (1 ECCP + 2 CCP) |
| ADC Channels | 12 x 10-bit | 12 x 10-bit | 12 x 10-bit | 12 x 10-bit | 8 x 10-bit | 12 x 10-bit |
| Unit Price (qty 100, USD, approx) | 1.82 | 1.85 | 1.92 | 1.95 | 1.65 | 1.80 |
Key Differentiators
- Largest Flash in 20-pin mid-range family (vs PIC16F677-I/P)
- NanoWatt technology for sub-µA sleep (vs PIC16F627A-I/P)
- 18 I/O versus 14-16 in legacy parts (vs PIC16F677-I/P)
- Industrial temperature in PDIP format (vs PIC16F685-E/SO)
Design Notes
Place a 100 nF ceramic decoupling capacitor within 5 mm of VDD (pin 1 and pin 20 - both are bonded internally; connecting both improves high-frequency decoupling). For designs using the ADC, add a 10 µF bulk capacitor at the analog AVDD/AVSS pair if separate analog pins are used, or at VDD if shared. The MCU's internal bandgap reference requires VDD > 2.2 V; below this, configure the ADC to use VDD as the reference. Avoid noisy switching loads on the same VDD rail as the MCU without an LC filter.
Estimated: At 20 MHz clock and full 5.5 V VDD, the PIC16F685-I/P typical supply current is ~ 8 mA, dissipating roughly 44 mW in the PDIP-20 package. The DIP-20 thermal resistance (θJA) is approximately 70 °C/W on a standard 2-layer board without copper pour, so junction temperature rise is only ~ 3 °C above ambient - thermal management is rarely a concern. However, for automotive under-hood or LED-driver applications with sustained high I/O toggling, add a copper pour and stitch vias to keep junction below 125 °C.
Reserve the ICSPDAT/ICSPCLK pins (RB7/RB6 on some PICs; on PIC16F685 the ICSP uses RB6/RB7 which are not bonded out on the 20-pin variant - programming is done via RB4/RB5 emulation or the dedicated ICSP pins on larger variants) on the connector. For the 20-pin PDIP, ensure RB6/ICSPCLK and RB7/ICSPDAT pads are accessible, or provide a 6-pin ICSP header for PICkit 3/4 debugging. Place the ICSP connector at the board edge to avoid clearance issues with test clips. Avoid long traces on OSC1/OSC2 to reduce EMI pickup - keep the crystal or resonator within 5 mm of the pins and guard the traces with ground.
Do not exceed the absolute maximum VDD of 7.5 V; the on-chip ESD clamp is rated for 4 kV HBM but sustained overvoltage destroys the part. Ensure that any unused I/O pin is configured as output low or input with internal weak pull-up to prevent floating-pin shoot-through current that can raise I_DD by 100 µA per pin. When using the EUSART, the baud-rate generator error is most accurate with HFINTOSC at 8 MHz or 16 MHz - the internal oscillator drifts ±2 % over temperature, so avoid tight baud-rate timing for protocols like LIN that demand ±1.5 %.
Compliance Information
RoHS compliant per Microchip product page. AEC-Q100 not qualified in the -I/P (industrial, PDIP) variant; automotive applications should use PIC16F685T-I/SO (AEC-Q100, SOIC) instead. Halogen-free status not stated in the verified web data.
