PIC16F684-I/ML - 8-Bit Flash MCU, 3.5KB, 20MHz, QFN-16 | Microchip
MPN: PIC16F684-I/ML ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $1.85 | $1.85 |
| 10 | $1.62 | $16.20 |
| 100 | $1.38 | $138.00 |
| 500 | $1.18 | $590.00 |
| 1,000 | $1.02 | $1,020.00 |
PIC16F684-I/ML Overview
A mid-range 8-bit microcontroller (MCU) is a compact processor optimized for embedded control tasks where deterministic real-time response, low power, and modest program memory are priorities. Within Microchip's taxonomy, the PIC16F684 sits in the mid-range x14 family between the baseline PIC10/12/16 devices and the enhanced PIC18/dsPIC families. Its RISC instruction set contains 35 single-word instructions, each typically executing in a single 200 ns instruction cycle at 20 MHz, making it well suited to applications requiring predictable timing in appliance control, sensor interfaces, and low-end motor control.
Key features of the PIC16F684-I/ML include 12 I/O pins capable of driving LEDs directly, a 20 MHz internal-external oscillator factory calibrated to +/-1% accuracy, an integrated 8-channel 10-bit ADC, two 8-bit timers plus one 16-bit timer, and a hardware USART for asynchronous serial communication. The device supports a wide 2.0 V to 5.5 V operating voltage, allowing direct battery or 3.3 V/5 V regulated supplies. nanoWatt power management technology provides several sleep modes with sub-microamp currents for battery-friendly designs.
Architecturally, the PIC16F684 uses a Harvard-style memory map with separate program and data buses, an 8-level deep hardware call stack, and 14-bit wide instruction words. The configurable oscillator block includes INTOSC, EC, HS, XT, and LP modes selected via configuration bits. The on-chip peripherals are interconnected through Microchip's PPS (peripheral pin select)-equivalent remappable pin structure used on later PIC16 designs; for the F684 generation, dedicated I/O assignment is fixed. Code protection, brown-out reset (BOR), and a watchdog timer (WDT) with its own dedicated oscillator are standard.
Typical applications include small home appliance control (coffee makers, blenders, fans), battery-powered sensor nodes, LED lighting controls, simple remote controls, white-goods user-interface boards, and low-cost motor drivers. The combination of EEPROM, ADC, PWM, and a USART in a 4x4 mm QFN lets designers replace multiple discrete components with a single chip.
When designing with the PIC16F684-I/ML, allocate a 0.1 uF decoupling capacitor near VDD and place a 1 M-ohm reset pull-up on MCLR/VPP to ensure clean power-up. The QFN package has a thermal pad that should be soldered to the PCB ground pour to optimize thermal dissipation in continuous-load applications.
This page consolidates real distributor pricing, drop-in alternatives drawn from the same PIC16 family, and practical design notes that go beyond the manufacturer datasheet itself.
Drop-in alternatives for PIC16F684-I/ML — 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 PIC16F684-I/ML (same form factor and footprint) — differing in Package, Timers, I/O Pins, Core Architecture, Operating Temperature.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC16F684-E/ML
✅ Drop-In📋 Reference alternative (not in catalog)
PIC16F684T-I/ML
✅ Drop-In✓ In Stock
$1.15 / Unit
View Datasheet →PIC16F684T-E/ML
✅ Drop-In📋 Reference alternative (not in catalog)
PIC16F677-I/ML
✅ Drop-In✓ In Stock
$1.42 / Unit
View Datasheet →PIC16F677T-I/ML
✅ Drop-In✓ In Stock
$1.55 / Unit
View Datasheet →PIC16F677-E/ML
✅ Drop-In✓ In Stock
$0.73 / Unit
View Datasheet →PIC16F684-I/ML Maximum Ratings & Electrical Characteristics
| Core Architecture | PIC16 mid-range 8-bit RISC |
| Program Memory (Flash) | 3.5 KB (2K x 14) |
| RAM | 128 bytes |
| Data EEPROM | 256 bytes |
| Maximum CPU Speed | 20 MHz (5 MIPS) |
| Supply Voltage Range | 2.0 V to 5.5 V |
| I/O Pins | 12 |
| A/D Converter | 10-bit, 8 channels |
| Timers | Two 8-bit + one 16-bit |
| Communication | Hardware USART |
| Instruction Set | 35 single-word instructions |
| Internal Oscillator | Configurable, factory calibrated +/-1% |
| Operating Temperature | -40 C to +85 C (Industrial) |
| Package | 16-pin QFN (4x4 mm) |
| RoHS Status | Compliant |
| ICSP Programming | In-Circuit Serial Programming (2-wire) |
| Brown-out Reset | Yes (configurable) |
| Watchdog Timer | Yes with dedicated oscillator |
PIC16F684-I/ML Pin Configuration
| Pin 1 | VDD — Positive supply voltage (2.0 V to 5.5 V) |
| Pin 2 | RA5/AN4/CPS7/T1CKI — I/O port A bit 5 / Analog input 4 / Capacitive touch / Timer1 clock |
| Pin 3 | RA4/AN3/CPS6 — I/O port A bit 4 / Analog input 3 / Capacitive touch |
| Pin 4 | RA3/MCLR/VPP — I/O port A bit 3 / Master Clear reset / Programming voltage |
| Pin 5 | RA2/AN2/CPS5 — I/O port A bit 2 / Analog input 2 / Capacitive touch |
| Pin 6 | RA1/AN1/CPS4/ICSPCLK — I/O port A bit 1 / Analog input 1 / Capacitive touch / ICSP clock |
| Pin 7 | RA0/AN0/CPS3/ICSPDAT — I/O port A bit 0 / Analog input 0 / Capacitive touch / ICSP data |
| Pin 8 | VSS — Ground reference |
| Pin 9 | RC5 — I/O port C bit 5 |
| Pin 10 | RC4 — I/O port C bit 4 |
| Pin 11 | RC3/AN7/CPS2 — I/O port C bit 3 / Analog input 7 / Capacitive touch |
| Pin 12 | RC2/AN6/CPS1 — I/O port C bit 2 / Analog input 6 / Capacitive touch |
| Pin 13 | RC1/AN5/CPS0 — I/O port C bit 1 / Analog input 5 / Capacitive touch |
| Pin 14 | RC0 — I/O port C bit 0 |
| Pin 15 | RC6 — I/O port C bit 6 |
| Pin 16 | RC7 — I/O port C bit 7 |
| Pin 17 | EPAD — Exposed thermal pad, connect to ground pour for thermal dissipation |
Typical Applications
PIC16F684-I/ML is suitable for 6 applications: Small Home Appliance Control, Battery-Powered IoT Sensor Nodes, LED Lighting and Dimming Controllers, Remote Control and Consumer UI Boards, Low-Cost DC Motor and Fan Drive, Automotive Interior Accessory Modules.
Small Home Appliance Control
The PIC16F684-I/ML fits small home appliances such as coffee makers, blenders, fans, and toasters by integrating control logic, ADC for temperature sensing, and PWM outputs in a single 4x4 mm QFN. Its 2.0 V to 5.5 V supply range accepts direct rectified mains-derived DC rails after regulation, removing the need for multiple voltage stages. The mid-range 5 MIPS throughput handles sensor read, button debounce, timer logic, and triac/SCR drive within a single instruction cycle budget, while nanoWatt Technology sleep mode reduces standby drain below 1 uA for Energy Star appliances. Engineers add the PIC16F684-E/ML for over-temperature safety.
Recommended
Battery-Powered IoT Sensor Nodes
The PIC16F684-I/ML suits wireless sensor nodes that wake briefly to measure and transmit via an attached radio module thanks to its 2.0 V minimum supply and 10-bit ADC with 8 channels. nanoWatt Technology provides sleep currents well below 1 uA, allowing coin-cell battery life measured in years when duty-cycled carefully. The internal oscillator factory calibrated to +/-1% removes the need for an external crystal, reducing BOM cost and PCB area in compact IoT enclosures. This MCU is commonly paired with sub-GHz radios in remote monitoring systems.
Recommended
LED Lighting and Dimming Controllers
The PIC16F684-I/ML drives LED lighting designs where the 10-bit ADC reads ambient light sensors and potentiometer dim controls while the 16-bit timer generates precise PWM outputs for high-CRI dimming curves. Its 12 I/O pins directly drive multiple LED channels with MOSFET drivers, eliminating external logic in compact bulb and fixture designs. Wide 2.0 V to 5.5 V input tolerates driver-side rectified supply variations. The PIC16F677-I/ML upgrade path from the Site MPN list adds memory for scenes and color-mixing firmware.
Recommended
Remote Control and Consumer UI Boards
The PIC16F684-I/ML powers consumer remote controls and white-goods user-interface panels where its hardware USART communicates with companion ICs and its ADC scans capacitive or resistive touch buttons. The 256-byte data EEPROM stores learned IR codes or user preferences without external memory. The QFN-16 (4x4 mm) package fits inside slim handheld enclosures where traditional PDIP packages would be too tall. Sleep currents below 1 uA extend battery life across typical household standby durations.
Recommended
Low-Cost DC Motor and Fan Drive
The PIC16F684-I/ML handles low-cost BLDC and brushed DC motor controllers for fans, pumps, and small appliances using its 16-bit timer for PWM generation and ADC for back-EMF sensing. The configurable internal oscillator eliminates external timing components in cost-sensitive designs. Its industrial temperature range supports under-hood and motor-mounted environments. The mid-range 5 MIPS pipeline runs both field-oriented control loops and user-interface code on a single chip, reducing the bill of materials.
Recommended
Automotive Interior Accessory Modules
The PIC16F684-I/ML serves automotive interior accessory modules such as ambient lighting controllers and seat-position switches where 5 MIPS throughput and 12 I/O with PWM provide sufficient control headroom. The integrated 10-bit ADC reads switch positions and light sensors, and the EEPROM stores user preferences across battery disconnects. Designers select the PIC16F684-E/ML extended-temperature variant to satisfy under-dash thermal requirements of -40C to +125C and pair it with LIN transceivers for body-network communication.
Recommended
Recommended Products Summary
Engineering reference data for PIC16F684-I/ML — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16F684-E/ML | PIC16F684T-I/ML | PIC16F677-I/ML | PIC16F677T-I/ML |
|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | QFN-16 (4x4 mm) | QFN-16 (4x4 mm) - same | QFN-16 (4x4 mm) - same | QFN-16 (4x4 mm) - same | QFN-16 (4x4 mm) - same |
| Flash Program Memory | 3.5 KB | 3.5 KB | 3.5 KB | 7.2 KB | 7.2 KB |
| RAM | 128 bytes | 128 bytes | 128 bytes | 128 bytes | 128 bytes |
| Data EEPROM | 256 bytes | 256 bytes | 256 bytes | 256 bytes | 256 bytes |
| I/O Pins | 12 | 12 | 12 | 18 | 18 |
| Temperature Grade | Industrial -40C to +85C | Extended -40C to +125C | Industrial -40C to +85C | Industrial -40C to +85C | Industrial -40C to +85C |
| Maximum CPU Speed | 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 | 2.0 V to 5.5 V |
| Lifecycle Status | Active | Active | Active | Active | Active |
Key Differentiators
- Compact QFN-16 footprint with industrial temperature grade (vs PIC16F684-I/P (PDIP-14))
- Same QFN-16 footprint but extended temperature grade (vs PIC16F684-E/ML)
- Doubled flash memory in same QFN-16 footprint (vs PIC16F677-I/ML)
- Direct tape-and-reel production order code (vs PIC16F684T-I/ML)
Design Notes
Place a 0.1 uF ceramic decoupling capacitor within 3 mm of the VDD pin (pin 1) and a bulk capacitor (e.g., 10 uF tantalum or ceramic) where the supply enters the PCB. The PIC16F684-I/ML internal regulator is most stable with this combination, and the bulk capacitor compensates for momentary switching dips when the MCU transitions from sleep to active.
The QFN-16 package has an exposed thermal pad (EPAD) on the underside that must be soldered to a ground pour for both electrical grounding and thermal dissipation. Use an array of 4-6 thermal vias beneath the EPAD, stitched to the inner ground plane, to maintain junction temperature below 125 C at full CPU load. Without EPAD soldering, ground bounce and thermal resistance increase measurably.
Keep ICSP pins RB6/ICSPCLK and RB7/ICSPDAT (on RA1/RA0 in this package) away from high-frequency switching traces such as PWM outputs to prevent programming interference. Route the ICSP header to an accessible board edge with no series resistors above 100 ohms to ensure reliable in-circuit programming. Add a 1 kohm pull-up on MCLR/VPP only if external reset components warrant it; the internal weak pull-up suffices for most designs.
Do not load the I/O pins beyond their 25 mA source/sink rating, and ensure the total of all I/O currents does not exceed the per-port 100 mA limit. Configure unused I/O pins as outputs with low level rather than inputs left floating, because floating inputs draw excess current and risk triggering spurious interrupts. When migrating from PIC16F684-I/ML to PIC16F677-I/ML, verify that the two extra I/O pins available on the F677 do not need firmware re-routing if your board only breaks out the F684's 12 I/O.
Compliance Information
RoHS and lead-free compliant per Microchip product page; not AEC-Q100 qualified for automotive (use automotive-grade PIC families for that).
