PIC16F628T-04/SS - 8-Bit 4MHz PIC MCU 3.5KB Flash SSOP-20 | Microchip
MPN: PIC16F628T-04/SS ✗ End of Life| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $3.85 | $3.85 |
| 10 | $3.47 | $34.70 |
| 100 | $3.04 | $304.00 |
| 500 | $2.66 | $1,330.00 |
| 1,000 | $2.32 | $2,320.00 |
| 3,000 | $1.99 | $5,970.00 |
PIC16F628T-04/SS Overview
A microcontroller (MCU) is a single-chip computer that integrates a CPU core, program memory, working RAM, peripherals, and interrupt logic into one IC, enabling compact embedded control. The PIC16F628 belongs to the enhanced mid-range PIC16 architecture, sits inside the PIC microcontroller product line, and ultimately within the broader category of microcontrollers and embedded processors. It is widely used as a small-footprint, deterministic 8-bit controller for cost-sensitive designs.
Key features include nanoWatt technology for low-power operation, an internal 4 MHz RC oscillator with software calibration, a Watchdog Timer with its own on-chip RC oscillator, multiplexed MCLR pin, programmable weak pull-ups on PORTB, and an in-circuit serial programming (ICSP) interface that allows firmware updates after PCB assembly. The device operates across 3.0 V to 5.5 V, supports DC to 20 MHz external clock operation, and is fully static.
The PIC16F628T-04/SS uses a Harvard RISC architecture with a single accumulator and a 14-bit instruction word, providing deterministic interrupt response and instruction timing. Its CMOS process technology gives low quiescent current and high code-density, while the SSOP-20 package offers a small footprint for compact PCB designs. Compared with the PIC16F84, it adds a USART, two comparators with a programmable VREF, PWM hardware, and EEPROM data memory.
Typical applications include appliance controls, hobby and educational projects, sensor signal conditioning, low-end motor and lighting controllers, and battery-powered instrumentation. The combination of internal oscillator, brown-out reset, and analog comparators allows designers to reduce external components and shrink BOM cost. The part is also a strong fit for migrating legacy PIC16F84A designs where additional peripherals are required.
When designing with this device, note that the "-04" suffix denotes the 4 MHz rated version; designers requiring higher throughput should consider the PIC16F628-20 variant (20 MHz) or the pin-compatible PIC16F628A family with enhanced peripherals. Ensure decoupling (100 nF plus bulk) is placed close to VDD/SS, and respect the in-circuit programming pinout so that no production components block ICSP access.
This page synthesizes verified distributor pricing, drop-in alternatives drawn from the same PIC16F family, and practical design notes not consolidated in the manufacturer datasheet, delivering the cross-reference and trade-off analysis engineers actually need before placing an order.
Drop-in alternatives for PIC16F628T-04/SS — 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/SS (same form factor and footprint) — differing in Package, I/O Pins, Core Architecture, Operating Temperature, Internal Oscillator.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC16F628A-I/SS
✅ Drop-In✓ In Stock
$1.41 / Unit
View Datasheet →PIC16F628AT-I/SO
✅ Drop-In✓ In Stock
$1.92 / Unit
View Datasheet →PIC16F628AT-E/SS
✅ Drop-In✓ In Stock
$1.98 / Unit
View Datasheet →PIC16F628-04E/SS
✅ Drop-In✓ In Stock
$2.1 / Unit
View Datasheet →PIC16F627T-04/SS
✅ Drop-In✓ In Stock
$1.7 / Unit
View Datasheet →PIC16F627A-I/SS
✅ Drop-In✓ In Stock
$1.12 / Unit
View Datasheet →PIC16F628T-04/SS Maximum Ratings & Electrical Characteristics
| Core Architecture | PIC16 Enhanced Mid-range (Harvard, RISC, 14-bit instruction) |
| Data Bus Width | 8 bit |
| Maximum Clock Frequency | 20 MHz (external); 4 MHz rated variant |
| Program Memory Type | Flash |
| Program Memory Size | 3.5 KB (2K x 14 words) |
| Data RAM | 224 bytes |
| Data EEPROM | 128 bytes |
| Supply Voltage Range | 3.0 V to 5.5 V |
| I/O Pins | 16 (with high-current sink/source) |
| Timers | 3 (Timer0, Timer1, Timer2) |
| PWM Channels | 1 x 10-bit |
| Analog Comparators | 2 with programmable on-chip VREF |
| Communication Peripherals | USART with on-chip baud-rate generator |
| Watchdog Timer | Yes, with dedicated on-chip RC oscillator |
| Brown-out Detect (BOD) | Programmable |
| Internal Oscillator | 4 MHz RC, software calibratable |
| Package | 20-pin SSOP (209.6 mil, 5.30 mm body) |
| Mounting Type | Surface Mount |
| Operating Temperature Range | 0 C to +70 C (commercial, /SS suffix) |
| Power-on Reset / Power-up Timer | Yes (POR + PWRT) |
| ICSP (In-Circuit Serial Programming) | Yes |
| RoHS Status | Compliant |
PIC16F628T-04/SS Pin Configuration
| Pin 1 | RA2 — Bidirectional I/O port A bit 2 |
| Pin 2 | RA3 — Bidirectional I/O port A bit 3 |
| Pin 3 | RA4/T0CKI — I/O port A bit 4 / Timer0 clock input |
| Pin 4 | RA5/MCLR/VPP — I/O port A bit 5 / Master Clear (active-low reset) / Programming voltage |
| Pin 5 | VSS — Ground reference |
| Pin 6 | RB0/INT — I/O port B bit 0 / External interrupt input |
| Pin 7 | RB1 — Bidirectional I/O port B bit 1 |
| Pin 8 | RB2 — Bidirectional I/O port B bit 2 |
| Pin 9 | RB3/PGM — I/O port B bit 3 / LVP programming enable |
| Pin 10 | RB4 — Bidirectional I/O port B bit 4 (interrupt-on-change) |
| Pin 11 | RB5 — Bidirectional I/O port B bit 5 (interrupt-on-change) |
| Pin 12 | RB6/PGC — I/O port B bit 6 / ICSP serial clock |
| Pin 13 | RB7/PGD — I/O port B bit 7 / ICSP serial data |
| Pin 14 | VDD — Positive supply voltage |
| Pin 15 | RA6/OSC2 — I/O port A bit 6 / Oscillator crystal output |
| Pin 16 | RA7/OSC1 — I/O port A bit 7 / Oscillator crystal input |
| Pin 17 | RA0 — Bidirectional I/O port A bit 0 / AN0 analog input |
| Pin 18 | RA1 — Bidirectional I/O port A bit 1 / AN1 analog input |
| Pin 19 | VDD — Positive supply voltage (second pin) |
| Pin 20 | VSS — Ground reference (second pin) |
Typical Applications
PIC16F628T-04/SS is suitable for 6 applications: Appliance Control Board, Battery-Powered Sensor Node, Hobby / Educational Robotics, Industrial Sensor Signal Conditioning, Lighting and PWM Control, Legacy PIC16F84A Migration.
Appliance Control Board
The PIC16F628T-04/SS fits appliance control boards thanks to its 16 high-current I/O pins capable of directly sinking/source to drive relays, triac optocouplers, LEDs, and 7-segment displays, eliminating the need for external drivers. Its 3.5 KB Flash and 224 B RAM hold small state-machine firmware for washing machines, microwave ovens, and HVAC controllers. The internal 4 MHz RC oscillator removes two external crystals from the BOM, while the programmable BOD and Power-on Reset guarantee defined behavior across the universal 3.3 V / 5 V mains-derivative rails typical in white goods. The USART with on-chip baud-rate generator simplifies service-port diagnostics, and the SSOP-20 footprint is narrow enough to fit behind a control-panel display.
Recommended
Battery-Powered Sensor Node
For battery-powered sensor nodes, the PIC16F628T-04/SS is a strong fit thanks to its nanoWatt technology low-power modes, internal 4 MHz RC oscillator that eliminates the external crystal, and only 3.0 V minimum supply so it can run directly from two AA cells. Its two analog comparators with programmable on-chip VREF allow threshold detection against a bandgap reference without spinning up the ADC core, and the 128-byte EEPROM provides non-volatile storage for calibration coefficients and unique node IDs. The SSOP-20 footprint is small enough to fit inside sensor-housing PCBs, and the 16 I/O pins are sufficient for SPI/I2C sensor interfaces plus wake-up interrupt pins.
Recommended
Hobby / Educational Robotics
The PIC16F628T-04/SS is widely adopted in hobby robotics and educational kits because of its 3.5 KB Flash (enough for line-following, wall-avoidance, and simple PID control loops), its USART for HC-05 Bluetooth serial bridges, and its 10-bit PWM channel for hobby servo control. The internal 4 MHz oscillator plus ICSP lets students program the device in-circuit without removing it from the robot chassis. Its SSOP-20 footprint and 16 I/O pins comfortably fit sensor arrays, motor drivers, and indicator LEDs on a typical Arduino-sized PCB, and the PICkit 3 / PICkit 5 programmer ecosystem is widely available in classroom and maker spaces.
Recommended
Industrial Sensor Signal Conditioning
In industrial signal-conditioning front-ends, the PIC16F628T-04/SS fits well because of its two on-chip analog comparators with programmable VREF, which can directly implement window comparators for over-temperature, over-current, and level-detection circuits without any external op-amps. The USART bridges to RS-485 transceivers for factory-floor networking, while the programmable brown-out reset and watchdog timer keep the controller alive on noisy 24 V / 5 V derived rails. With 224 B of RAM for state buffers and 128 B of EEPROM for factory calibration storage, the PIC16F628T-04/SS can host a complete smart-sensor node in a compact SSOP-20 footprint suitable for DIN-rail mounted boards.
Recommended
Lighting and PWM Control
The PIC16F628T-04/SS is a classic choice for low-end lighting controllers because of its 10-bit PWM hardware module, 16 high-current I/O pins that drive MOSFET gates directly, and internal 4 MHz oscillator that lets designers skip an external crystal. The 3.5 KB Flash comfortably stores fade curves, scene presets, and DMX-512 framing routines for stage lighting strips or RGB controllers. The SSOP-20 footprint fits inside miniature inline LED dimmers, while the USART enables DMX-512 reception with an external RS-485 transceiver. Programmable BOD ensures clean startup from capacitive LED-driver rails without flickering, and the 128-byte EEPROM preserves user-set brightness scenes through power cycles.
Recommended
Legacy PIC16F84A Migration
The PIC16F628T-04/SS is one of the most common drop-in upgrades for legacy PIC16F84A designs because it retains the SSOP-20 pinout, adds 128 B of EEPROM that the F84A lacked, and doubles the program memory to 3.5 KB. Its USART, two analog comparators with programmable VREF, and PWM hardware let engineers modernize product firmware without any PCB rework. The internal 4 MHz RC oscillator eliminates the external resonator, freeing two I/O pins. The PIC16F628T-04/SS therefore allows direct board-level substitution on legacy 16F84A boards while supporting enhanced peripherals, with an upgrade path to the PIC16F628A-I/SS for production continuity.
Recommended
Recommended Products Summary
Engineering reference data for PIC16F628T-04/SS — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC16F628A-I/SS | PIC16F628AT-I/SO | PIC16F628AT-E/SS | PIC16F628-04E/SS | PIC16F627T-04/SS | PIC16F627A-I/SS |
|---|---|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | SSOP-20 (209.6 mil) | SSOP-20 - same | SSOP-20 - same | SSOP-20 - same | SSOP-20 - same | SSOP-20 - same | SSOP-20 - same |
| Program Memory (Flash) | 3.5 KB (2K x 14) | 3.5 KB | 3.5 KB | 3.5 KB | 3.5 KB | 1 KB (-71%) | 1 KB (-71%) |
| Data RAM | 224 B | 224 B | 224 B | 224 B | 224 B | 128 B | 128 B |
| Data EEPROM | 128 B | 128 B | 128 B | 128 B | 128 B | 128 B | 128 B |
| Operating Temperature | 0 C to +70 C (commercial) | -40 C to +85 C (industrial) | -40 C to +85 C | -40 C to +125 C (extended) | -40 C to +125 C | 0 C to +70 C | -40 C to +85 C |
| Max Clock Frequency | 4 MHz rated (20 MHz external) | 20 MHz | 20 MHz | 20 MHz | 4 MHz rated (20 MHz external) | 4 MHz rated (20 MHz external) | 20 MHz |
| ADC Module | No (2 comparators only) | Yes (8-channel 10-bit) | Yes (8-channel 10-bit) | Yes (8-channel 10-bit) | No (2 comparators only) | No | Yes |
| Internal RC Oscillator | 4 MHz, software calibrated | 4 MHz / 8 MHz selectable, calibrated | 4 MHz / 8 MHz selectable | 4 MHz / 8 MHz selectable | 4 MHz, calibrated | 4 MHz | 4 MHz / 8 MHz selectable |
| Lifecycle Status | NRND | Active | Active | Active | NRND | NRND | Active |
Key Differentiators
- Drop-in pin-compatible with active PIC16F628A-I/SS family (vs PIC16F628A-I/SS)
- Smaller Flash in PIC16F627 alternative creates a 30% memory gap (vs PIC16F627T-04/SS)
- Internal 4 MHz oscillator plus nanoWatt sleep (vs PIC16F628-04E/SS (tube variant))
Design Notes
Estimated: At VDD=5 V, VIL clock-on, and 4 MHz operation, the PIC16F628T-04/SS typically draws ~2 mA active and ~1 uA in sleep mode per the Microchip nanoWatt section. Always place a 100 nF ceramic decoupling capacitor within 5 mm of the VDD pins (14 and 19) and a 10 uF bulk capacitor on the same rail to suppress switching noise from PWM and USART transitions. For battery-powered designs, enter sleep between events and wake via the RB0/INT pin or the analog comparator to extend coin-cell life to multi-year endurance.
Keep the ICSP trace between RB6/PGC and RB7/PGD short (<50 mm) and avoid running them adjacent to the PWM or relay-drive traces on RB4-RB5 to prevent programming errors during in-circuit programming. The MCLR/VPP pin (pin 4) requires a 10 kohm pull-up to VDD and a 100 nF capacitor to ground for in-circuit programming isolation; failure to include this network will cause programming failures on production boards. Maintain a continuous ground pour under the SSOP-20 package and route both VDD pins (14 and 19) in parallel for low-impedance supply distribution.
Do not assume the internal 4 MHz RC oscillator is accurate enough for USART baud-rate communication above 9600 baud at 5 V; the factory calibration gives approximately 1% accuracy but temperature drift can reach 2%. For reliable serial links above 9600 baud, either use an external crystal on RA6/OSC2 and RA7/OSC1 or recalibrate the OSCCAL register per the Microchip errata. Also note that the -04 speed grade caps instruction throughput at 4 MHz (1 MIPS); if the firmware requires faster interrupt response, migrate to the PIC16F628A-I/SS at 20 MHz (5 MIPS) before PCB release.
Route the analog comparator inputs (RA0-RA3) away from digital switching traces and place a small RC low-pass filter (10 kohm + 100 pF) at each analog input to suppress EMI pickup in noisy industrial environments. Reference Microchip application note AN679 for recommended analog layout practices for PIC16F enhanced mid-range parts. The exposed SSOP-20 plastic body has limited thermal dissipation, so a continuous ground pour under the package is sufficient for typical commercial 0 C to +70 C operation; no explicit thermal copper beyond normal signal routing is required.
Compliance Information
RoHS and lead-free status confirmed by Microchip product packaging marking. AEC-Q100 is not applicable because the commercial 0 C to +70 C temperature grade is not automotive-qualified; for automotive designs, choose PIC16F628A-I/SS or a Q-graded PIC16F18xxx device.
