PIC16F628T-04/SO - 4MHz 8-Bit Flash MCU 3.5KB SOIC-18
MPN: PIC16F628T-04/SO ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $3.95 | $3.95 |
| 10 | $3.65 | $36.50 |
| 100 | $3.1 | $310.00 |
| 500 | $2.55 | $1,275.00 |
| 1,000 | $2.2 | $2,200.00 |
PIC16F628T-04/SO Overview
A microcontroller (MCU) is a single-chip computer that integrates a CPU, memory and programmable I/O peripherals; the PIC16F628 family belongs to Microchip's 8-bit PIC® RISC architecture family, which traces its lineage from the PIC1650 and remains one of the longest-deployed 8-bit MCU cores in industrial, automotive and consumer electronics. The PIC16F628 series was the first mid-range PIC family to migrate from EPROM/ROM to flash, enabling in-circuit reprogramming via ICSP. The hierarchy: 8-bit MCU -> PIC® RISC MCU -> PIC16F mid-range family -> PIC16F628 sub-family.
Key features include an internal 4 MHz RC oscillator with calibration, 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, and programmable weak pull-ups on PORTB. Two analog comparators with programmable on-chip voltage reference and a capture/compare/PWM (CCP) peripheral extend its analog/mixed-signal capability beyond pure digital I/O. The -04 speed grade (4 MHz) distinguishes it from the -20 (20 MHz) sibling in the same silicon.
The enhanced mid-range core adds hardware interrupt context saving, a deeper hardware stack (8 levels), and an extended instruction set with 35 single-word instructions, enabling compact C and assembly firmware. ICSP (in-circuit serial programming) and ICD (in-circuit debugging) via RB6/RB7 free the I/O pins for end-application use rather than burning them as programming interfaces. Internal EEPROM permits 1 M erase/write cycles, supporting data logging and user-configurable parameter storage without external memory.
Typical applications include automotive and industrial sensor interfaces, low-power remote control transmitters, appliance controllers, small-form-factor motor control loops, simple protocol bridges (UART/I2C firmware conversion), and battery-powered instrumentation where the wide 3.0-5.5 V supply range and internal oscillator simplify BOM. The part remains a benchmark for hobbyist, education and legacy drop-in designs that migrate from PIC16C84/16F84 to a higher-memory, more feature-rich flash MCU.
When designing with this MCU, note that the -04 grade limits operation to 4 MHz (DC-20 ns); design firmware timing budgets around the 200 ns instruction execution, and account for the SOIC-18 thermal envelope when used in sealed enclosures. Microchip's MPLAB X IDE and the PICkit 5 in-circuit debugger support this device for development and production programming.
Drop-in alternatives for PIC16F628T-04/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 PIC16F628T-04/SO (same form factor and footprint) — differing in Operating Temperature, Package, Internal Oscillator, Analog Comparators, Core Architecture.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC16F628-04/SO
✅ Drop-In✓ In Stock
$1.05 / Unit
View Datasheet →PIC16F628A-I/SO
✅ Drop-In✓ In Stock
$2.32 / Unit
View Datasheet →PIC16F628-04I/SO
✅ Drop-In✓ In Stock
$2.3 / Unit
View Datasheet →PIC16F628-04E/SO
✅ Drop-In✓ In Stock
$1.78 / Unit
View Datasheet →PIC16F628AT-I/SO
✅ Drop-In✓ In Stock
$1.92 / Unit
View Datasheet →PIC16F628AT-E/SO
✅ Drop-In✓ In Stock
$1.92 / Unit
View Datasheet →PIC16F627-04/SO
✅ Drop-In📋 Reference alternative (not in catalog)
PIC16F627AT-I/SO
✅ Drop-In✓ In Stock
$1.83 / Unit
View Datasheet →PIC16F628T-04/SO Maximum Ratings & Electrical Characteristics
| Core Architecture | PIC16 enhanced mid-range 8-bit RISC |
| Instruction Set Width | 14-bit |
| Number of Instructions | 35 single-word |
| Maximum Clock Speed | 4 MHz (DC-04 grade) |
| Instruction Cycle Time | 200 ns |
| Program Memory (Flash) | 3.5 KB (2K x 14) |
| RAM | 224 bytes |
| EEPROM Data Memory | 128 bytes |
| Digital I/O Pins | 16 (PORTA + PORTB) |
| Supply Voltage | 3.0 V to 5.5 V (F-version) |
| Internal Oscillator | 4 MHz RC, factory calibrated |
| Watchdog Timer | Yes, dedicated on-chip RC oscillator |
| Brown-Out Detect | Yes, programmable |
| Power-On Reset / PWRT / OST | Yes |
| Analog Comparators | 2 with programmable voltage reference |
| CCP Module | 1 Capture/Compare/PWM |
| ICSP / ICD | Yes, on RB6/RB7 |
| Hardware Stack | 8 levels |
| Package | 18-pin SOIC (SO), wide body |
| Mounting Type | Surface Mount |
| Operating Temperature | -40C to +85C (industrial) |
| RoHS Status | Compliant |
| MSL Level | 1 (unlimited floor life at <30C/85% RH) |
PIC16F628T-04/SO Pin Configuration
| Pin 1 | RA0/AN0 — Digital I/O / Analog input 0 / CVREF |
| Pin 2 | RA1/AN1 — Digital I/O / Analog input 1 / VREF+ |
| Pin 3 | RA2/AN2 — Digital I/O / Analog input 2 / VREF- |
| Pin 4 | RA3/MCLR/VPP — Digital input / Master Clear (reset) / Programming voltage |
| Pin 5 | RA4/TOCKI/C1OUT — Digital I/O (open-drain) / Timer0 clock / Comparator 1 output |
| Pin 6 | RA5/AN4/C2OUT — Digital I/O / Analog input 4 / Comparator 2 output |
| Pin 7 | RA6/OSC2/CLKOUT — Digital I/O / Oscillator output / Clock output |
| Pin 8 | RA7/OSC1/CLKIN — Digital I/O / Oscillator input / External clock input |
| Pin 9 | RB0/INT — Digital I/O / External interrupt |
| Pin 10 | RB1/RX/DT — Digital I/O / USART RX / Data (synchronous) |
| Pin 11 | RB2/TX/CK — Digital I/O / USART TX / Clock (synchronous) |
| Pin 12 | RB3/CCP1 — Digital I/O / Capture/Compare/PWM |
| Pin 13 | RB4/PGM — Digital I/O / Low-voltage programming input |
| Pin 14 | VSS — Ground reference |
| Pin 15 | VDD — Positive supply voltage (3.0 V to 5.5 V) |
| Pin 16 | RB5 — Digital I/O |
| Pin 17 | RB6/PGC — Digital I/O / ICSP clock (programming/debug) |
| Pin 18 | RB7/PGD — Digital I/O / ICSP data (programming/debug) |
Typical Applications
PIC16F628T-04/SO is suitable for 7 applications: Industrial Sensor Interface Module, Appliance Control Board, Remote Control / IR Transmitter, Automotive Body Electronics (Non-Safety), Battery-Powered Instrumentation, Legacy Drop-In Replacement for PIC16F84, Educational / Hobbyist Development.
Industrial Sensor Interface Module
The PIC16F628T-04/SO's 16 digital I/O, 3.0-5.5 V supply range, internal 4 MHz RC oscillator, and 224 B RAM suit industrial sensor front-ends where the MCU reads digital sensors, performs linearization, and drives a UART/relay output. The internal oscillator eliminates external crystals, cutting BOM cost and PCB area in sealed sensor housings; the BOD protects flash integrity from industrial supply transients. Pin-compatible SOIC-18 footprint supports same-board migration to PIC16F628A or PIC16F18444 when more memory is needed.
Recommended
Appliance Control Board
Small appliances such as coffee makers, washing-machine sub-modules and HVAC damper actuators use the PIC16F628T-04/SO for relay/triac drive, push-button scan and LED status display. The CCP module generates PWM for soft-start of brushed DC motors; the 2 analog comparators replace external op-amps for current-sensing. The 18-SOIC wide-body package withstands wave-soldering and high-temperature potting common in white-goods manufacturing; tape-and-reel format supports SMT production lines.
Recommended
Remote Control / IR Transmitter
Battery-powered IR remote controls benefit from the PIC16F628T-04/SO's internal 4 MHz oscillator (no external crystal), 3.0 V operation from 2xAA cells, and low sleep current. The CCP PWM output drives a 38 kHz IR carrier with software-modulated data, and 224 B RAM accommodates button-scan state machines for several dozen keys. The wide 3.0-5.5 V supply range tolerates weak NiMH battery voltage without brown-out resets during transmission bursts.
Recommended
Automotive Body Electronics (Non-Safety)
Non-safety automotive subsystems such as seat controllers, mirror adjusters and lighting dimmers use the PIC16F628T-04/SO for cost-driven designs where AEC-Q100 is not mandatory. The 16 I/O drive LED arrays directly via MOSFETs, and the internal 4 MHz oscillator eliminates external resonator failure modes. For AEC-Q100-grade projects, Microchip recommends migrating to PIC16F1xxx automotive lines; this part remains in active production for industrial and consumer-grade automotive accessories.
Recommended
Battery-Powered Instrumentation
Portable data loggers, hand-held meters and battery-backed instrumentation benefit from the PIC16F628T-04/SO's wide 3.0-5.5 V supply range, 128-byte EEPROM for parameter storage and 224 B RAM for local buffering. The internal 4 MHz RC oscillator reduces quiescent current draw versus external crystal start-up surges; the WDT with dedicated RC oscillator provides reliable firmware recovery in unattended field deployments. EEPROM endurance of 1M cycles supports frequent user-config writes in metering applications.
Recommended
Legacy Drop-In Replacement for PIC16F84
Designs originally built around the PIC16F84A can migrate directly to PIC16F628T-04/SO as a 100% pin-compatible upgrade with 8x more flash (3.5 KB vs 1 KB), 4x more RAM, internal EEPROM and the enhanced mid-range instruction set. The 18-pin SOIC package matches the PIC16F84A footprint; ICSP programming pins RB6/RB7 allow in-circuit firmware upgrades in the field. The drop-in migration enables modernizing legacy designs without PCB redesign or firmware porting work.
Recommended
Educational / Hobbyist Development
The PIC16F628T-04/SO is a long-standing favorite in university microcontroller courses and hobbyist electronics because of its simple 35-instruction RISC core, well-documented PIC16F627/628 datasheet, and broad ICSP tool support. The 18-SOIC wide-body package fits 0.1-inch-pitch breadboard adapters; the internal 4 MHz oscillator lets beginners run simple programs without external components. MPLAB X IDE, XC8 compiler and PICkit 5 form a free development chain used in schools worldwide.
Recommended
Recommended Products Summary
Engineering reference data for PIC16F628T-04/SO — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16F628-04/SO | PIC16F628A-I/SO | PIC16F628AT-I/SO | PIC16F627-04/SO |
|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 18-SOIC (wide body, T/R) | 18-SOIC (wide body, tube) - same | 18-SOIC (wide body, tube) - same | 18-SOIC (wide body, T/R) - same | 18-SOIC (wide body, tube) - same |
| Flash Program Memory | 3.5 KB (2K x 14) | 3.5 KB | 3.5 KB | 3.5 KB | 1.75 KB (-50%) |
| Maximum Clock Speed | 4 MHz (DC-04 grade) | 4 MHz | 20 MHz (-04A) | 20 MHz | 4 MHz |
| RAM | 224 bytes | 224 bytes | 224 bytes | 224 bytes | 224 bytes |
| EEPROM Data Memory | 128 bytes | 128 bytes | 128 bytes | 128 bytes | 128 bytes |
| Digital I/O | 16 | 16 | 16 | 16 | 16 |
| Supply Voltage | 3.0 V to 5.5 V | 3.0 V to 5.5 V | 2.0 V to 5.5 V (wider range) | 2.0 V to 5.5 V | 3.0 V to 5.5 V |
| Operating Temperature | -40C to +85C (industrial) | -40C to +85C | -40C to +85C | -40C to +85C | -40C to +85C |
| Internal Oscillator | 4 MHz RC factory calibrated | 4 MHz RC | 4 MHz RC + improved accuracy | 4 MHz RC | 4 MHz RC |
Key Differentiators
- Tape-and-reel packaging for SMT production (vs PIC16F628-04/SO)
- Mature enhanced mid-range PIC16 core (vs PIC16F627-04/SO)
- Industry-standard ICSP and ICD on RB6/RB7 (vs PIC16F84A-04/SO)
- Internal 4 MHz oscillator eliminates external crystal (vs PIC16F84A-20/P)
Design Notes
The PIC16F628T-04/SO accepts 3.0 V to 5.5 V on VDD (pin 14) with VSS on pin 5. Place a 100 nF decoupling capacitor as close as possible to the VDD/VSS pair, and add a 10 uF bulk capacitor at the regulator output to handle transient current demands during flash programming (programming current can briefly reach 50 mA at 5 V). Tie the MCLR/RA3/VPP pin to VDD through a 10 kohm pull-up resistor unless external reset control is required; never leave MCLR floating.
Route the ICSP signals RB6/PGC and RB7/PGD to a 5-pin header (PGC, PGD, VDD, VSS, MCLR/VPP) so the PICkit 5 or ICD can program and debug the device in-circuit without removing it. Keep traces to the crystal/oscillator pins (RA6/OSC2 and RA7/OSC1) short and guarded by a ground pour to minimize EMI coupling when using an external resonator. The wide-body 18-SOIC package provides ample pad area for hand-soldering prototypes and standard reflow profiles; peak reflow temperature per IPC/JEDEC J-STD-020 should not exceed 260C.
Configuration word bits must be set correctly before the MCU runs user code: enable the internal 4 MHz oscillator if no external crystal is fitted, set the WDT postscaler and enable/disable as needed, and configure BOD voltage. Failing to disable the watchdog in firmware without periodic CLRWDT will cause unexpected resets. When migrating from PIC16F84, note that PIC16F628 has additional analog functions on PORTA that must be configured as digital by clearing the CMCON and VRCON registers, or analog inputs will block digital reads.
The PIC16F628T-04/SO's internal 4 MHz RC oscillator is factory calibrated to within +/-1% at 5 V/25C; it can drift +/-5% across -40C to +85C and +/-10% across the 3.0-5.5 V supply range. For UART communication requiring tight baud-rate accuracy, use the BRGH=1 high-speed mode and validate the calculated SPBRG error against the UART specification; if timing is critical, switch to an external crystal. The CCP PWM output frequency is derived from Timer2 and should be calculated as fOSC/(4*(PR2+1)*TMR2_prescaler); keep TMR2 prescaler at 1:1 for highest PWM frequency.
Estimated: The PIC16F628T-04/SO in 18-SOIC wide-body has a theta_JA of approximately 70 C/W (typical for 18-SOIC). At maximum operating current of ~15 mA at 5 V, dissipation is 75 mW, yielding a junction rise of only 5 C above ambient; thermal management is generally unnecessary. In sealed enclosures above 60C ambient, verify the IC stays below the +85C industrial limit by derating supply voltage to 5.0 V or switching to the lower-power PIC16F1825 family.
Compliance Information
RoHS compliant and lead-free per Microchip product page. Not AEC-Q100 qualified - the PIC16F628T-04/SO is intended for industrial and consumer markets, not automotive safety-critical applications. For AEC-Q100-grade 8-bit PIC parts, review Microchip's PIC16F1xxx automotive lines.
