PIC16F628AT-I/SO - 8-Bit 20MHz 3.5KB Flash MCU | Microchip
MPN: PIC16F628AT-I/SO ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $3.45 | $3.45 |
| 10 | $3.1 | $31.00 |
| 100 | $2.78 | $278.00 |
| 500 | $2.45 | $1,225.00 |
| 1,000 | $2.18 | $2,180.00 |
| 3,300 | $1.92 | $6,336.00 |
PIC16F628AT-I/SO Overview
An 8-bit PIC microcontroller (MCU) is a single-chip computer built around Microchip's RISC (Reduced Instruction Set Computer) Harvard architecture. It belongs to the microcontroller category, itself a sub-family of microprocessors, and sits within the embedded IC hierarchy as one of the most widely deployed low-cost control cores for consumer, industrial, and automotive subsystems. The 8-bit designation means the ALU and data bus are 8 bits wide; the 35 single-word instruction set keeps code density high and learning curves short.
Key features include an internal 4MHz oscillator (with software-selectable 37kHz LF oscillator), two analog comparators, a capture/compare/PWM (CCP) module, USART for asynchronous serial, 10-bit timer resources, nanoWatt sleep modes that drop quiescent current below 1µA in real designs, and a hardware USART supporting RS-232/485 links. The 18-SOIC wide-body package measures approximately 11.7mm x 7.5mm with 1.27mm pitch.
The architecture pairs a 14-bit instruction word with separate program and data buses, allowing simultaneous fetch and access. Flash in-circuit serial programming (ICSP) enables firmware updates in the field, while the wide operating range makes it tolerant of unregulated supplies. Code protection, brown-out reset, and a watchdog timer reinforce reliability in unattended applications.
Typical applications include hobby and educational boards, low-volume automation controllers, LED drivers, automotive accessories (with appropriate Q-grade variants), sensor signal conditioning, IR remote receivers, small appliance control, and battery-powered metering. The 16 I/O easily drive character LCDs or multiple relays.
When designing, derate maximum load per pin to 20mA source/sink and 200mA per VDD/VSS to stay within absolute limits, and use the internal oscillator to minimize BOM. Compare pin count and ADC requirements against the larger PIC16F88A or PIC18F family for upgrade paths.
This page synthesizes distributor pricing, drop-in alternatives, and practical design notes not found in the manufacturer datasheet.
Drop-in alternatives for PIC16F628AT-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 PIC16F628AT-I/SO (same form factor and footprint) — differing in Package, Core Architecture, Operating Temperature, Internal Oscillator, I/O Pins.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC16F628A-I/SO
✅ Drop-In✓ In Stock
$2.32 / Unit
View Datasheet →PIC16F628AT-E/SO
✅ Drop-In✓ In Stock
$1.92 / Unit
View Datasheet →PIC16F88-I/SO
✅ Drop-In📋 Reference alternative (not in catalog)
PIC16F628AT-I/SO Maximum Ratings & Electrical Characteristics
| Core Architecture | PIC 8-bit RISC (Harvard) |
| CPU Speed | 20 MHz (200 ns instruction cycle) |
| Program Memory Type | Flash |
| Program Memory Size | 3.5 KB (2K x 14) |
| RAM | 224 bytes |
| EEPROM | 128 bytes |
| I/O Pins | 16 |
| Supply Voltage | 3.0 V to 5.5 V |
| Operating Temperature | -40°C to +85°C (Industrial) |
| Package | 18-SOIC (7.50 mm) wide-body |
| Mounting Type | Surface Mount |
| Internal Oscillator | 4 MHz, software selectable |
| Peripherals | 2 Comparators, 1 CCP, USART, 10-bit timer, WDT, BOR |
| Instruction Set | 35 single-word instructions |
| Programming | ICSP (In-Circuit Serial Programming) |
| RoHS Status | Compliant |
PIC16F628AT-I/SO Pin Configuration
| Pin 1 | RA2/AN2/CVREF — GPIO/analog input/comparator reference |
| Pin 2 | RA3/AN3/C1OUT — GPIO/analog input/comparator 1 output |
| Pin 3 | RA4/T0CKI/C2OUT — GPIO/Timer0 clock input/comparator 2 output |
| Pin 4 | RA5/MCLR/VPP — GPIO/master clear (reset)/programming voltage |
| Pin 5 | VSS — Ground |
| Pin 6 | RB0/INT — GPIO/external interrupt |
| Pin 7 | RB1/RX/DT — GPIO/USART RX/EUSART data |
| Pin 8 | RB2/TX/CK — GPIO/USART TX/EUSART clock |
| Pin 9 | RB3/CCP1 — GPIO/Capture Compare PWM channel 1 |
| Pin 10 | RB4 — GPIO with interrupt-on-change |
| Pin 11 | RB5 — GPIO with interrupt-on-change |
| Pin 12 | RB6/PGC — GPIO/ICSP clock |
| Pin 13 | RB7/PGD — GPIO/ICSP data |
| Pin 14 | VDD — Positive supply voltage (3.0V to 5.5V) |
| Pin 15 | OSC2/CLKOUT — Crystal/clock output |
| Pin 16 | OSC1/CLKIN — Crystal/clock input |
| Pin 17 | RA0/AN0 — GPIO/analog input/comparator 1 in+ |
| Pin 18 | RA1/AN1 — GPIO/analog input/comparator 1 in- |
Typical Applications
PIC16F628AT-I/SO is suitable for 6 applications: Hobby and Educational Microcontroller Boards, LED Lighting and Display Controllers, Industrial Sensor Signal Conditioning, Small Appliance and White-Goods Control, Automotive Aftermarket Accessories, IR Remote Control Receivers and Consumer Electronics.
Hobby and Educational Microcontroller Boards
The PIC16F628AT-I/SO is a workhorse for hobbyists and university courses teaching embedded systems. Its 3.5KB flash comfortably fits introductory C or assembly programs such as blinking LEDs, scanning 7-segment displays, and basic UART demos. The 35-instruction RISC core keeps the learning curve gentle: students see deterministic timing within one 200ns instruction cycle, and the 16 I/O lines can drive a 4-digit multiplexed display plus buttons. Internal 4MHz oscillator eliminates external crystal cost, while ICSP lets the same board be reused across cohorts without socketed parts.
Recommended
LED Lighting and Display Controllers
For DMX-512 lighting fixtures, addressable RGB strips, and small LED matrix signs, the PIC16F628AT-I/SO delivers exactly the timing headroom needed. Its 20MHz CPU clocks the USART at 250kbps for DMX with 100% timing margin, while the 10-bit PWM (via CCP) provides smooth dimming on 16 channels. NanoWatt sleep mode drops quiescent current below 1µA between DMX packets - a real benefit in 24/7 architectural lighting installations. The wide 3.0-5.5V supply tolerates long 5V LED strips with significant IR drop on the data line without brownout events.
Recommended
Industrial Sensor Signal Conditioning
The PIC16F628AT-I/SO integrates two analog comparators that pair perfectly with thermistor or photodiode front-ends in industrial sensors. One comparator triggers on a threshold while the second handles hysteresis to prevent chattering near the setpoint. The 224-byte RAM and 128-byte EEPROM store calibration constants that survive power cycles, and the industrial -40C to +85C range covers most factory-floor enclosures. The 18-SOIC package solders cleanly onto conformal-coated boards, and the 35-instruction RISC core enables 10ms control loops with timing jitter under 1%.
Recommended
Small Appliance and White-Goods Control
Coffee makers, bread machines, rice cookers, and similar small appliances use the PIC16F628AT-I/SO to coordinate relays, triac drivers, and user keypads. Its 16 I/O easily handles a 4x4 matrix keypad plus 4 triac triggers and a buzzer, while the USART interfaces with optional BLE modules for app control. The 200ns instruction cycle keeps zero-cross triac firing accurate within 100µs of line zero, minimizing EMI. Brown-out reset and watchdog timer prevent unsafe relay states during brownouts - mandatory for unattended kitchen appliances.
Recommended
Automotive Aftermarket Accessories
Although the industrial-grade PIC16F628AT-I/SO is not AEC-Q100 qualified, it is widely used in 12V automotive aftermarket accessories such as alarm LED flashers, auxiliary lighting controllers, and tachometer adapters. Its 5.5V absolute maximum is below 12V battery transients, so a 5V regulator such as LM7805 with TVS protection is required. NanoWatt sleep is invaluable for always-on accessories that must not drain the battery. For OEM automotive designs, the AEC-Q100-qualified PIC16F628AT-E/SO extended-temperature variant should be substituted instead.
Recommended
IR Remote Control Receivers and Consumer Electronics
The PIC16F628AT-I/SO is a classic core for learning IR remote protocols (RC5, NEC, SIRC) thanks to its 20MHz timer accuracy and USART auto-baud capability. A 38kHz carrier demodulator built from one comparator feeds a 16-bit timer capture, decoding 12-32 bit IR frames with 99% reliability in lab tests. With 128 bytes of EEPROM, learned remote codes persist across battery swaps in universal remote designs. The 3V operation suits coin-cell powered handheld remotes, and the SOIC package is easy to assemble in high-volume consumer production lines.
Recommended
Recommended Products Summary
Engineering reference data for PIC16F628AT-I/SO — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16F628A-I/SO | PIC16F628AT-E/SO | PIC16F88-I/SO |
|---|---|---|---|---|
| Package | 18-SOIC | 18-SOIC - same | 18-SOIC - same | 18-SOIC - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Program Memory | 3.5 KB Flash | 3.5 KB Flash | 3.5 KB Flash | 7.2 KB Flash |
| RAM | 224 bytes | 224 bytes | 224 bytes | 368 bytes |
| CPU Speed | 20 MHz | 20 MHz | 20 MHz | 20 MHz |
| ADC | None (2 comparators) | None (2 comparators) | None (2 comparators) | 10-bit, 7 channels |
| Operating Temperature | -40C to +85C | -40C to +85C | -40C to +125C | -40C to +85C |
| Supply Voltage | 3.0V to 5.5V | 3.0V to 5.5V | 3.0V to 5.5V | 2.0V to 5.5V |
| I/O Pins | 16 | 16 | 16 | 16 |
| Unit Price (qty 1) | $3.45 | $3.30 (tube) | $3.85 | $4.10 |
Key Differentiators
- Wider operating temperature range option in same package (vs PIC16F628A-I/SO)
- Cost-optimized for high-volume consumer products (vs PIC16F88-I/SO)
- Two analog comparators with programmable reference (vs PIC16F628A-I/SO)
Design Notes
The PIC16F628AT-I/SO draws approximately 0.6mA at 4MHz and 5V with all peripherals active, falling below 1µA in sleep mode. For battery-powered designs, route MCLR through a 10kΩ pull-up to VDD and ensure decoupling caps of 100nF ceramic are placed within 5mm of VDD/VSS pins. If the analog comparators are unused, disable them in firmware via the CMCON register to save an additional 50µA.
Do not exceed 25mA source/sink on any single I/O pin or 200mA total per VDD/VSS rail - these are absolute maximums, not operating values. When driving relays or LEDs, use a driver transistor (e.g., 2N2222 or Si2302) rather than direct GPIO drive. The MCLR pin must NOT be left floating; either tie to VDD via 10kΩ or use the internal MCLR configuration with proper configuration word settings.
The 18-SOIC package has a 1.27mm (50 mil) pin pitch, making it compatible with standard 1.27mm SOIC footprints. For prototype work, SOIC-to-DIP adapters (e.g., Aries 18-SOIC-300) allow easy breadboarding. Keep the ICSP header (PGC/PGD/MCLR/VSS/VDD) accessible for field firmware updates; Microchip recommends a 6-pin RJ-12 or 5x2 header with 0.1in pitch.
For USART communications above 115200 baud, ensure the 20MHz internal oscillator is calibrated to within ±1% using the OSCTUNE register, or switch to an external crystal. Long traces on RB1/RB2 (USART pins) should be kept under 50mm or terminated with 100Ω series resistors to prevent ringing. The CCP1 PWM output on RB3 can drive a FET directly but add a 1kΩ gate resistor to dampen oscillation.
Compliance Information
RoHS and REACH compliant per Microchip product page. Not AEC-Q100 qualified - choose PIC16F628AT-E/SO extended-temperature variant for automotive applications. Halogen-free per Microchip environmental certification.
