PIC16F628-20/P - 8-bit 20MHz 3.5KB Flash MCU | Microchip
MPN: PIC16F628-20/P ✗ End of Life| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $3.42 | $3.42 |
| 10 | $3.07 | $30.70 |
| 100 | $2.61 | $261.00 |
| 500 | $2.28 | $1,140.00 |
| 1,000 | $1.96 | $1,960.00 |
PIC16F628-20/P Overview
What is an 8-bit Flash microcontroller? An 8-bit Flash microcontroller is a single-chip computer that fetches, decodes, and executes 8-bit-wide instructions from non-volatile Flash program memory, providing in-system reprogrammability via ICSP. The PIC16F628 belongs to the mid-range PIC16 family, which sits between the baseline PIC10/12/16 family and the enhanced PIC18 family in Microchip's taxonomy. As a member of the broader category of microcontrollers (MCU) > microcomputer > embedded processor > semiconductor, the PIC16F628 combines on-chip peripherals, RISC architecture, and Flash storage to replace discrete logic in embedded designs.
Key features include an integrated 4 MHz internal oscillator (selectable), Power-on Reset (POR), Power-up Timer (PWRT), Oscillator Start-up Timer (OST), Brown-out Detect (BOD), Watchdog Timer (WDT) with its own on-chip RC oscillator, multiplexed MCLR pin, programmable weak pull-ups on PORTB, and a USART module for serial communication. The device operates from 3.0V to 5.5V and supports in-circuit serial programming (ICSP) for field upgrades.
Architecturally, the PIC16F628 uses a Harvard-style RISC core with separate program and data buses, enabling simultaneous instruction fetch and operand access for predictable 200 ns cycle times at 20 MHz. The on-chip peripherals are accessed through a memory-mapped register architecture, with interrupt handling driven by a 14-bit instruction word and a hardware stack. Compared to legacy ROM-based PICs, the Flash implementation enables low-volume prototyping without mask charges.
Typical applications include consumer appliance control, HVAC thermostat logic, industrial sensor conditioning, automotive interior accessories, remote controls, and battery-powered instrumentation. The wide supply range (3.0V-5.5V) makes the part equally suitable for 5V industrial systems and 3.3V battery-operated designs.
When designing with this MCU, ensure decoupling capacitors of 0.1 uF are placed close to VDD, and that the MCLR pin is properly biased with a 10 kohm pull-up to VDD for normal operation. For low-power modes, consult the SLEEP instruction and oscillator switching options documented in the manufacturer datasheet.
This page synthesizes distributor pricing, drop-in alternatives, and practical design notes not found in the manufacturer datasheet, including supply-chain lifecycle flags and verified 18-pin PDIP drop-in equivalents.
Drop-in alternatives for PIC16F628-20/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 PIC16F628-20/P (same form factor and footprint) — differing in Package, Operating Temperature, Timers, Core Architecture, I/O Pins.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC16F628A-I/P
✅ Drop-In✓ In Stock
$1.62 / Unit
View Datasheet →PIC16F627A-I/P
✅ Drop-In📋 Reference alternative (not in catalog)
PIC16F627-20/P
✅ Drop-In✓ In Stock
$1.74 / Unit
View Datasheet →PIC16F627-20I/P
✅ Drop-In✓ In Stock
$2.18 / Unit
View Datasheet →PIC16F628-04I/SO
✅ Drop-In✓ In Stock
$2.3 / Unit
View Datasheet →PIC16F628-04I/SO
✅ Drop-In✓ In Stock
$2.3 / Unit
View Datasheet →PIC16F628-20/P Maximum Ratings & Electrical Characteristics
| Core Architecture | PIC16 RISC, 8-bit, Harvard |
| Maximum Clock Speed | 20 MHz |
| Instruction Cycle | 200 ns |
| Program Memory (Flash) | 3.5 KB (2K x 14) |
| RAM | 224 bytes |
| EEPROM Data Memory | 128 bytes |
| I/O Pins | 16 (PORTA + PORTB) |
| Supply Voltage | 3.0 V to 5.5 V |
| Package Type | 18-pin PDIP (0.300 inch, 7.62 mm) |
| Mounting Type | Through-Hole (DIP) |
| Instruction Set | 35 single-word instructions |
| Operating Temperature | -40C to +85C (industrial), 0C to +70C (commercial) |
| On-chip Oscillator | Internal 4 MHz (selectable) |
| Communication Peripherals | USART |
| RoHS Status | Compliant (lead-free) |
| Programming | ICSP (In-Circuit Serial Programming) |
PIC16F628-20/P Pin Configuration
| Pin 1 | RA2/AN2 — Bidirectional I/O; analog channel 2 |
| Pin 2 | RA3/AN3 — Bidirectional I/O; analog channel 3 |
| Pin 3 | RA4/AN4 — Bidirectional I/O; analog channel 4 |
| Pin 4 | RA5/MCLR/Vpp — Bidirectional I/O; Master Clear (reset, active low); programming voltage input |
| Pin 5 | VSS — Ground reference |
| Pin 6 | RB0/INT — Bidirectional I/O; external interrupt |
| Pin 7 | RB1/RX/DT — Bidirectional I/O; USART RX or synchronous data |
| Pin 8 | RB2/TX/CK — Bidirectional I/O; USART TX or synchronous clock |
| Pin 9 | RB3/CCP1 — Bidirectional I/O; CCP1 peripheral |
| Pin 10 | RB4/PGM — Bidirectional I/O; low-voltage programming |
| Pin 11 | RB5 — Bidirectional I/O |
| Pin 12 | RB6/T1OSO/T1CKI — Bidirectional I/O; Timer1 oscillator or clock input |
| Pin 13 | RB7/T1OSI — Bidirectional I/O; Timer1 oscillator input |
| Pin 14 | VDD — Positive supply (3.0V to 5.5V) |
| Pin 15 | OSC2/CLKOUT — Oscillator output / clock out |
| Pin 16 | OSC1/CLKIN — Oscillator input / external clock in |
| Pin 17 | RA6/OSC1/CLKIN — Bidirectional I/O / alternate oscillator input |
| Pin 18 | RA7/OSC2/CLKOUT — Bidirectional I/O / alternate oscillator output |
Typical Applications
PIC16F628-20/P is suitable for 6 applications: Consumer Appliance Control, Industrial Sensor Conditioning, Remote Control and Wireless Keyfob, HVAC Thermostat Controller, Automotive Interior Accessories, Battery-Powered Instrumentation.
Consumer Appliance Control
The PIC16F628-20/P fits consumer appliance control because its 20 MHz RISC core executes instruction in 200 ns, fast enough for real-time keypad scanning, relay timing, and triac-based load control. The 3.5 KB Flash holds appliance firmware including mode tables, fault handling, and beep patterns. Its 16 digital I/O directly drive LED indicators, seven-segment displays, and keypad matrices, while the USART interfaces to inverter boards or sensor modules. Brown-out detect (BOD) and watchdog timer (WDT) keep the design safe through mains brownouts.
Recommended
Industrial Sensor Conditioning
The PIC16F628-20/P is well suited to industrial sensor conditioning because the 16 I/O pins accept 4-20 mA loop inputs through op-amp front ends and switch-level digital sensor lines. EEPROM (128 bytes) stores calibration coefficients per channel, while Flash stores the linearization math. The integrated Brown-out Reset and Power-up Timer ensure deterministic operation across industrial 24V rail transients, and the 20 MHz core runs PID loops at sub-millisecond period.
Recommended
Remote Control and Wireless Keyfob
The PIC16F628-20/P suits remote control keyfobs because the 3.0V-5.5V supply range supports 3V coin-cell battery operation, and the integrated 4 MHz internal oscillator eliminates the external crystal, saving PCB area. The device's SLEEP mode plus WDT enable multi-year battery life by sleeping between button presses. USART can drive an external RF transmitter module at 2400-9600 baud, and the 16 I/O can scan a 4x4 keypad matrix.
Recommended
HVAC Thermostat Controller
The PIC16F628-20/P works as an HVAC thermostat controller because the integrated USART interfaces to the indoor unit's serial bus, while the 16 I/O scan thermistor inputs through ADC-free comparator circuits or external ADC. The 3.5 KB Flash supports seven-day programmable schedules with hysteresis, and EEPROM retains user settings through power cycles. Watchdog timer and brown-out detect ensure the unit recovers gracefully from transient brown-outs common in HVAC line wiring.
Recommended
Automotive Interior Accessories
The PIC16F628-20/P can serve automotive interior accessories (window controls, seat controllers, lighting) where 12V battery-rail transients are present. With operating range of 3.0V-5.5V downstream of a 5V regulator, the device handles digital logic reliably. The USART supports body-control networks or LIN slaves through external transceivers, and the 16 I/O drive relays and switches with appropriate buffering. Although not AEC-Q100 qualified (the PIC16F628A-I/P is also commercial grade), simple accessories can leverage the part when extra automotive qualification is not mandated.
Recommended
Battery-Powered Instrumentation
The PIC16F628-20/P excels in battery-powered instrumentation such as handheld multimeters, gas detectors, and field data loggers because the wide 3.0V-5.5V supply supports both lithium and alkaline chemistries. The internal 4 MHz oscillator eliminates external crystals, reducing BOM cost and quiescent draw, while software-controlled oscillator switching lets the core step down to 32 kHz watch-crystal timekeeping. EEPROM stores calibration data for years without battery backup.
Recommended
Recommended Products Summary
Engineering reference data for PIC16F628-20/P — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16F628A-I/P | PIC16F627A-I/P | PIC16F627-20/P |
|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 18-pin PDIP | 18-pin PDIP - same | 18-pin PDIP - same | 18-pin PDIP - same |
| Core | PIC16 RISC, 8-bit | PIC16 RISC, 8-bit (improved) | PIC16 RISC, 8-bit | PIC16 RISC, 8-bit |
| Maximum Clock | 20 MHz | 20 MHz | 20 MHz | 20 MHz |
| Program Flash | 3.5 KB | 3.5 KB | 1.75 KB (-50%) | 1.75 KB (-50%) |
| RAM | 224 bytes | 224 bytes | 96 bytes (-57%) | 224 bytes |
| Supply Voltage | 3.0 V to 5.5 V | 2.0 V to 5.5 V (wider) | 2.0 V to 5.5 V | 3.0 V to 5.5 V |
| Operating Temperature | -40C to +85C (industrial) | -40C to +85C (industrial) | -40C to +85C | -40C to +85C |
| Silicon Revision | Original | A (improved) | A (improved) | Original |
Key Differentiators
- Original silicon revision still supported for legacy programs (vs PIC16F628A-I/P)
- Larger Flash than PIC16F627 family (vs PIC16F627-20/P)
- Wide supply voltage supports 3.3V and 5V systems in one part (vs PIC16F628A-I/P (2.0V-5.5V))
Design Notes
Place a 0.1 uF decoupling capacitor as close as possible to the VDD pin (pin 14) on every PIC16F628-20/P design to suppress voltage transients caused by I/O switching. For designs with noisy 5V rails, add a 10 uF bulk capacitor at the regulator output, and consider ferrite beads on the supply trace. Brown-out Detect (BOD) should be enabled to force a controlled reset if VDD falls below threshold, preventing code execution from corrupted Flash.
The MCLR pin (pin 4) must be tied through a 10 kohm pull-up resistor to VDD for normal operation. For ICSP programming, route the ICSPDAT and ICSPCLK signals to dedicated test pads or header pins to allow field firmware updates without removing the MCU from the board. Keep clock traces (OSC1/OSC2) short and away from high-current switching traces to reduce EMI coupling.
Do not confuse the PIC16F628 (3.5 KB Flash) with PIC16F627 (1.75 KB Flash) - the two parts share the same 18-pin PDIP pinout but differ by half the program memory. For code that compiles for PIC16F628 only, the PIC16F627 will not have enough Flash for the binary image. The PIC16F628A revision is the correct drop-in upgrade for PIC16F628 due to improved internal oscillator accuracy.
Compliance Information
RoHS compliant per Microchip product page. Not AEC-Q100 qualified - choose PIC16F628A-I/P variants or AEC-Q100-qualified PIC16 families for automotive applications.
