PIC18F4550 USB Microcontroller ICs in DIP-40 & TQFP-44
PIC18F4550 USB microcontrollers for through-hole and surface-mount designs
Shop loose PIC18F4550 8-bit microcontroller ICs by exact package and quantity. The current selection contains PIC18F4550-I/P DIP-40 one-piece listings and a PIC18F4550-I/PT TQFP-44 listing with separate one- and five-piece variants. These are bare ICs for a designed circuit or a compatible replacement footprint, not assembled development boards, USB breakout modules or preprogrammed application kits. Select the full suffix before ordering: PIC18F4550-I/P and PIC18F4550-I/PT have different mechanical packages and pin arrangements even though they share a device-family name.
Package and lot selection
- PIC18F4550-I/P, DIP-40: a 40-pin through-hole package for a matching PCB or socket. The two DIP product offers each describe one chip per lot and have a single default option. Confirm pin-1 orientation, body and row spacing, footprint and the full package suffix for a replacement.
- PIC18F4550-I/PT, TQFP-44: a 44-pin surface-mount package. Its variant labelled “Color” actually selects PIC18F4550-IPT 1PCS or PIC18F4550-IPT 5PCS; these are alternative lot sizes, not colors or one mixed pack. Check the lead pitch, board land pattern, pin-1 indicator and assembly method. Product wording also says “TFQP,” apparently a transposition of TQFP; verify the exact marking and package drawing rather than using that typo as a footprint specification.
Plan the USB and firmware design
The TQFP offer describes on-chip USB low-speed and full-speed functionality, an on-chip transceiver and USB support memory, along with oscillator/PLL options, timers, analog inputs, serial interfaces and ICSP/ICD capability. These are device-family design features, not a promise that a loose chip works as a USB peripheral when inserted into any circuit. A functional design still depends on the correct USB clock configuration, appropriate power and decoupling, the selected package pinout, external connection design, configuration bits and application firmware. Use the manufacturer's datasheet and reference information for the selected ordering code before designing a PCB or loading firmware.
The DIP listings use the shorthand “FLASH 16KX16,” while the TQFP listing uses “32KB” in a specification block. Those labels express memory in different units and should not be copied as competing claims of different installed capacity without confirming the manufacturer's organization and exact device revision. Likewise, the TQFP listing presents both a 4.2–5.5 V supply line and a wider 2.0–5.5 V feature claim. Do not treat either seller line as a universal operating guarantee for every clock and USB mode. Check the operating conditions and USB regulator requirements in the exact datasheet for your design.
Replacement and programming checklist
For a repair, compare the complete printed part number, package, pin mapping, power rails and the existing board's clock source and USB circuit. Do not assume that an empty replacement IC arrives with your equipment's firmware or configuration bits. For a new build, confirm the supported programming/debug interface, target voltage and compatible hardware/software toolchain before selecting a programmer. USB on the MCU does not mean a USB connector, crystal, firmware, bootloader, ICSP header or programmer is included with these loose-chip listings. The 44-pin part also advertises an optional dedicated debug/programming port; availability and pin assignment must be checked for its actual package and configuration.
Frequently asked questions
Can I put the TQFP-44 part in a DIP-40 socket? No. The surface-mount TQFP and through-hole DIP packages have different mechanical footprints and pin numbering. Select a part matching your PCB and recheck signals against the package pin diagram.
Does a one-piece order include a USB development board? No. The listed offers describe loose PIC18F4550 microcontroller chips. Any PCB, connector, power components or programming hardware must be identified and sourced separately unless an individual offer explicitly says otherwise.
Does the TQFP title mean five chips are always included? No. Choose the 1PCS or 5PCS variant. The DIP offers each describe one chip.
Will a blank PIC18F4550 enumerate over USB immediately? Do not assume so. USB operation depends on hardware wiring, power, clock/PLL settings and suitable firmware; the listings do not promise a programmed application or preloaded USB bootloader.
Is the advertised 48 MHz frequency valid at every supply voltage? Do not extrapolate a maximum-frequency headline across all operating conditions. Match supply, clock, temperature and USB operating mode to the exact device datasheet.
Can I substitute another PIC18 device with a similar name? Compare the full ordering code, package, pin functions, memory layout, USB peripheral, oscillator and firmware/configuration bits before considering a substitute.
