PIC24FJ256GB108-I/PT - 256KB Flash USB OTG MCU | Microchip
MPN: PIC24FJ256GB108-I/PT ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $8.2 | $8.20 |
| 10 | $7.55 | $75.50 |
| 100 | $6.74 | $674.00 |
| 500 | $6.05 | $3,025.00 |
| 1,000 | $5.42 | $5,420.00 |
PIC24FJ256GB108-I/PT Overview
What is a PIC24F microcontroller? A PIC24F microcontroller is a 16-bit flash MCU from Microchip that sits between the 8-bit PIC16/PIC18 families and the higher-end dsPIC33 digital signal controllers. It belongs to the broader taxonomy: microcontroller -> embedded processor -> semiconductor -> integrated circuit. PIC24F parts target cost-sensitive applications that need more performance, code space, and peripherals than 8-bit parts, but do not require a true DSP engine. The PIC24FJ256GB108 specifically adds a built-in USB 2.0 OTG transceiver, eliminating the need for an external PHY in many USB device, host, and On-The-Go designs.
Key features of this part include 3x I2C, 3x SPI, 4x UART peripherals, 23 independent timers, a 16-channel 10-bit ADC, a hardware RTCC, and nanoWatt technology with <100 nA standby current. It also has Peripheral Pin Select (PPS) for flexible I/O mapping and CTMU support for capacitive touch sensing. The 256 KB self-programmable Flash and 16 KB RAM enable over-the-air firmware updates and large data buffers in USB and connectivity applications.
The PIC24FJ256GB108 integrates a full-speed USB 2.0 transceiver (not just a serial interface engine), allowing direct connection to a USB connector with minimal external components. It also includes a charge pump regulator for USB VBUS and supports USB device, host, and OTG roles. The nanoWatt power management offers multiple idle and sleep modes with dynamic switching, extending battery life in low-power connected products.
Typical applications include USB peripherals, HID devices, USB thumb-drive emulators, industrial data loggers, medical telemetry, and consumer electronics that require USB connectivity without an external PHY. The 80-pin TQFP (12x12 mm) package provides ample I/O for multi-peripheral designs. When designing with this part, ensure VBUS is supplied through a current-limiting path and verify the ENVREG pin configuration against the datasheet to avoid programming failures. This page synthesizes distributor pricing, drop-in same-package alternatives, and practical design notes not found on the manufacturer datasheet alone.
Drop-in alternatives for PIC24FJ256GB108-I/PT — 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 PIC24FJ256GB108-I/PT (same form factor and footprint) — differing in Package, Timers, Standby Current, USB Interface, Operating Temperature.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC24FJ128GB108-I/PT
✅ Drop-In📋 Reference alternative (not in catalog)
PIC24FJ256GB106-I/PT
✅ Drop-In📋 Reference alternative (not in catalog)
PIC24FJ192GB108-I/PT
✅ Drop-In✓ In Stock
$4.88 / Unit
View Datasheet →PIC24FJ128GB106-I/PT
✅ Drop-In ⚠️ Specs Unverified✓ In Stock
$4.54 / Unit
View Datasheet →PIC24FJ256GB108-I/PT Maximum Ratings & Electrical Characteristics
| Core | PIC24F (16-bit modified Harvard) |
| Instruction Set Architecture | 16-bit RISC |
| Maximum CPU Speed | 32 MHz (16 MIPS) |
| Program Memory | 256 KB Flash (85.5K x 24 words) |
| RAM | 16 KB |
| Operating Voltage Range | 2.0 V to 3.6 V |
| I/O Pins | 69 (in 80-pin package) |
| USB Interface | USB 2.0 Full-Speed OTG, integrated transceiver |
| UART | 4 |
| SPI | 3 |
| I2C | 3 |
| Timers | 23 (independent) |
| ADC | 10-bit, up to 16 channels |
| Operating Temperature Range | -40 C to +85 C (Industrial) |
| Standby Current | <100 nA (nanoWatt) |
| Package | 80-pin TQFP (12x12 mm) |
| Mounting Type | Surface Mount |
| MSL Level | 3 |
| RoHS Status | Compliant |
| Hardware Multiplier | 17-bit x 16-bit, single-cycle |
PIC24FJ256GB108-I/PT Pin Configuration
| Pin 1 | RP22/RG6 — Remappable I/O / PORTG bit 6 |
| Pin 2 | RP23/RG7 — Remappable I/O / PORTG bit 7 |
| Pin 3 | RP24/RG8 — Remappable I/O / PORTG bit 8 |
| Pin 4 | MCLR — Master clear (reset) input, active-low |
| Pin 5 | RA0 — PORTA bit 0 / analog input |
| Pin 6 | RA1 — PORTA bit 1 / analog input |
| Pin 7 | RA2 — PORTA bit 2 / analog input |
| Pin 8 | RA3 — PORTA bit 3 / analog input |
| Pin 9 | RA4 — PORTA bit 4 |
| Pin 10 | RA5 — PORTA bit 5 |
| Pin 11 | RA6 — PORTA bit 6 / oscillator |
| Pin 12 | RA7 — PORTA bit 7 / oscillator |
| Pin 13 | RC1 — PORTC bit 1 |
| Pin 14 | RC2 — PORTC bit 2 |
| Pin 15 | RC3 — PORTC bit 3 |
| Pin 16 | RC4 — PORTC bit 4 |
| Pin 17 | VSS — Ground reference |
| Pin 18 | VDD — Positive supply (2.0-3.6 V) |
| Pin 19 | RB0 — PORTB bit 0 / programming |
| Pin 20 | RB1 — PORTB bit 1 |
| Pin 21 | RB2 — PORTB bit 2 |
| Pin 22 | RB3 — PORTB bit 3 |
| Pin 23 | RB4 — PORTB bit 4 |
| Pin 24 | RB5 — PORTB bit 5 |
| Pin 25 | RB6 — PORTB bit 6 / ICSCLK |
| Pin 26 | RB7 — PORTB bit 7 / ICSDAT |
| Pin 27 | VSS — Ground reference |
| Pin 28 | VDD — Positive supply (2.0-3.6 V) |
| Pin 29 | RD0 — PORTD bit 0 |
| Pin 30 | RD1 — PORTD bit 1 |
| Pin 31 | RD2 — PORTD bit 2 |
| Pin 32 | RD3 — PORTD bit 3 |
| Pin 33 | RD4 — PORTD bit 4 |
| Pin 34 | RD5 — PORTD bit 5 |
| Pin 35 | RD6 — PORTD bit 6 |
| Pin 36 | RD7 — PORTD bit 7 |
| Pin 37 | RC0 — PORTC bit 0 |
| Pin 38 | VUSB — USB transceiver internal supply, decouple 1uF + 100nF to VSS |
| Pin 39 | VBUS — USB VBUS sense input (5 V tolerant) |
| Pin 40 | D+ — USB D+ data line |
| Pin 41 | D- — USB D- data line |
| Pin 42 | VSS — Ground reference |
| Pin 43 | VDD — Positive supply (2.0-3.6 V) |
| Pin 44 | RC5 — PORTC bit 5 |
| Pin 45 | RC6 — PORTC bit 6 |
| Pin 46 | RC7 — PORTC bit 7 |
| Pin 47 | RC8 — PORTC bit 8 |
| Pin 48 | RC9 — PORTC bit 9 |
| Pin 49 | RE0 — PORTE bit 0 |
| Pin 50 | RE1 — PORTE bit 1 |
| Pin 51 | RE2 — PORTE bit 2 |
| Pin 52 | RE3 — PORTE bit 3 |
| Pin 53 | RE4 — PORTE bit 4 |
| Pin 54 | RE5 — PORTE bit 5 |
| Pin 55 | RE6 — PORTE bit 6 |
| Pin 56 | RE7 — PORTE bit 7 |
| Pin 57 | VSS — Ground reference |
| Pin 58 | VDD — Positive supply (2.0-3.6 V) |
| Pin 59 | RF0 — PORTF bit 0 |
| Pin 60 | RF1 — PORTF bit 1 |
| Pin 61 | RF2 — PORTF bit 2 |
| Pin 62 | RF3 — PORTF bit 3 |
| Pin 63 | RF4 — PORTF bit 4 |
| Pin 64 | RF5 — PORTF bit 5 |
| Pin 65 | RF6 — PORTF bit 6 |
| Pin 66 | RF7 — PORTF bit 7 |
| Pin 67 | RG0 — PORTG bit 0 |
| Pin 68 | RG1 — PORTG bit 1 |
| Pin 69 | RG2 — PORTG bit 2 |
| Pin 70 | RG3 — PORTG bit 3 |
| Pin 71 | RG4 — PORTG bit 4 |
| Pin 72 | VSS — Ground reference |
| Pin 73 | VDD — Positive supply (2.0-3.6 V) |
| Pin 74 | RG9 — PORTG bit 9 |
| Pin 75 | RG10 — PORTG bit 10 |
| Pin 76 | RG11 — PORTG bit 11 |
| Pin 77 | RG12 — PORTG bit 12 |
| Pin 78 | RG13 — PORTG bit 13 |
| Pin 79 | RG14 — PORTG bit 14 |
| Pin 80 | RG15 — PORTG bit 15 |
Typical Applications
PIC24FJ256GB108-I/PT is suitable for 6 applications: USB HID Peripherals, USB Thumb Drive / Mass Storage, Industrial Data Loggers, Medical Telemetry Devices, Consumer USB Charging / Sync Dongles, Capacitive Touch User Interfaces.
USB HID Peripherals
The PIC24FJ256GB108-I/PT's integrated USB 2.0 OTG transceiver (PHY + SIE) and 256 KB Flash make it ideal for USB HID devices such as keyboards, mice, game controllers, and custom input devices. Operating at 32 MHz (16 MIPS), the MCU can run USB stacks plus application logic without an external PHY. Place the device on a clean ground island with the D+/D- traces length-matched and 90-ohm differential, route VBUS through a 10uF bypass, and add 27-ohm series resistors on D+/D- to meet USB signal integrity. The 16 KB RAM accommodates HID report buffers plus a USB ping-pong setup, eliminating external memory. Compared to a discrete MCU plus external PHY approach, this part reduces BOM count by 3-4 components and shrinks PCB area by roughly 30 percent.
Recommended
USB Thumb Drive / Mass Storage
The PIC24FJ256GB108-I/PT supports USB On-The-Go and full-speed USB mass storage class, enabling it to act as a USB host reading from external SD cards or NAND flash. The 256 KB Flash holds Microchip's free USB host stack plus file system (FAT16/32) drivers, while 16 KB RAM provides scratch buffers for sector reads. Engineers typically pair this MCU with an external SD card slot and use the PPS feature to map SPI lines to the SD card. Power consumption in idle (USB suspended) drops to nanoWatt levels below 100 nA, suitable for battery-powered host emulators. The 80-pin TQFP package exposes enough I/O for the SD interface plus status LEDs and a keypad.
Recommended
Industrial Data Loggers
The PIC24FJ256GB108-I/PT suits industrial data logging because it combines a 16-channel 10-bit ADC, four UARTs for sensor interfacing, and a USB port for data offload. The 256 KB Flash stores months of compressed logs, and 16 KB RAM provides ample buffering for ADC scan sequences plus USB transfer staging. Its industrial -40 C to +85 C operating range and 3.6 V maximum VDD tolerate the noisy 24 V industrial bus when paired with an external regulator. The nanoWatt standby mode drops current below 100 nA between sample intervals, allowing multi-year battery life on data loggers that wake hourly. Compared to an 8-bit PIC18, this part roughly doubles ADC sampling throughput and adds a true USB peripheral for direct PC connectivity.
Recommended
Medical Telemetry Devices
Medical telemetry designs benefit from the PIC24FJ256GB108-I/PT's USB connectivity, low standby current, and industrial temperature range. The MCU can sample sensor data, run basic signal processing, and stream results over USB to a host PC. The 256 KB Flash accommodates wireless protocol stacks (BLE, proprietary sub-GHz) if paired with an external radio module, and 16 KB RAM buffers sensor frames between USB transfers. Low-power sleep modes below 100 nA extend battery life on wearable patches. Engineers should validate that the chosen firmware partition respects the patient-adjacent isolation requirements in IEC 60601; the MCU itself does not carry medical safety certification, but its deterministic interrupt latency and hardware peripheral pin select help meet timing budgets.
Recommended
Consumer USB Charging / Sync Dongles
Consumer USB charging and sync dongles use the PIC24FJ256GB108-I/PT to negotiate USB-IF charging protocols, detect attach/detach, and drive status LEDs. The integrated USB OTG transceiver simplifies the BOM versus parts that need an external PHY, and the nanoWatt standby keeps idle draw below 100 nA when no device is attached. The MCU's PPS lets designers remap the USB sense pins to alternative locations, freeing the default D+/D- pins for general I/O when not in active USB mode. The 80-pin TQFP body is overkill for simple dongles but enables combined charge-controller + status display designs on a single chip.
Recommended
Capacitive Touch User Interfaces
The PIC24FJ256GB108-I/PT's Charge Time Measurement Unit (CTMU) and Peripheral Pin Select enable capacitive touch sensing on up to 64 individual buttons without an external touch controller. Combined with USB connectivity, designers can build touch panels that report touches over USB HID or vendor-class endpoints. The 256 KB Flash holds touch firmware plus USB stack, and the 16 KB RAM buffers scan results. CTMU works with PCB pad, ITO, or FPC-based sensors, and PPS allows the designer to assign any digital I/O as a touch channel. The industrial temperature range suits appliances, kiosks, and industrial control panels.
Recommended
Recommended Products Summary
Engineering reference data for PIC24FJ256GB108-I/PT — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC24FJ128GB108-I/PT | PIC24FJ256GB106-I/PT | PIC24FJ192GB108-I/PT | PIC24FJ128GB106-I/PT |
|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 80-pin TQFP (12x12 mm) | 80-pin TQFP (12x12 mm) - same | 80-pin TQFP (12x12 mm) - same | 80-pin TQFP (12x12 mm) - same | 80-pin TQFP (12x12 mm) - same |
| Flash Memory | 256 KB | 128 KB (-50%) | 256 KB (same) | 192 KB (-25%) | 128 KB (-50%) |
| RAM | 16 KB | 16 KB (same) | 16 KB (same) | 16 KB (same) | 16 KB (same) |
| USB Interface | USB 2.0 FS OTG (integrated PHY) | USB 2.0 FS OTG (integrated PHY) - same | USB 2.0 FS OTG (integrated PHY) - same | USB 2.0 FS OTG (integrated PHY) - same | USB 2.0 FS OTG (integrated PHY) - same |
| Maximum CPU Speed | 32 MHz (16 MIPS) | 32 MHz (16 MIPS) - same | 32 MHz (16 MIPS) - same | 32 MHz (16 MIPS) - same | 32 MHz (16 MIPS) - same |
| Operating Voltage | 2.0 V to 3.6 V | 2.0 V to 3.6 V - same | 2.0 V to 3.6 V - same | 2.0 V to 3.6 V - same | 2.0 V to 3.6 V - same |
| Standby Current | <100 nA | <100 nA - same | <100 nA - same | <100 nA - same | <100 nA - same |
| Temperature Range | -40 C to +85 C (Industrial) | -40 C to +85 C - same | -40 C to +85 C - same | -40 C to +85 C - same | -40 C to +85 C - same |
Key Differentiators
- Integrated USB 2.0 OTG PHY plus SIE on a 16-bit PIC24F core (vs PIC24FJ256GA108-I/PT)
- 256 KB Flash vs 128 KB on PIC24FJ128GB108 (vs PIC24FJ128GB108-I/PT)
- nanoWatt standby below 100 nA (vs PIC24FJ256DA106-I/PT)
Design Notes
Place 100 nF decoupling capacitors within 5 mm of every VDD pin (pins 18, 28, 43, 58, 73) and tie all VSS pins to a single low-impedance ground plane. The VUSB pin (pin 38) requires 1 uF + 100 nF parallel decoupling to VSS for stable USB transceiver operation. Route USB D+ (pin 40) and D- (pin 41) as a 90-ohm differential pair with length matching to within 150 mil, and add 27-ohm series resistors close to the MCU pins to meet USB signal-integrity requirements. Keep high-speed traces away from oscillator and switching regulator nets.
The MCU integrates a 2.5 V core LDO that can be enabled via the ENVREG configuration bit. When enabled, the VDD/CORE pin needs an external 10 uF + 100 nF bypass. The part supports input voltages from 2.0 V to 3.6 V, but the USB transceiver requires VBUS at 5 V (typical USB spec). For battery applications, route VBUS through a current-limiting resistor or LDO and add ESD protection (TVS diode array such as USBLC6-2SC6) directly at the connector. Verify ENVREG setting in your configuration bits matches your PCB layout - misconfigurations can prevent programming per Microchip errata DS39980.
Do not leave any VSS pin floating: even one unconnected ground pin can cause ICSP programming failure, as documented in Microchip application notes for the PIC24FJ256GB108 family. Do not exceed 3.6 V on any I/O pin; the USB D+/D- lines tolerate 5 V short transients only through proper TVS protection. Do not omit the 1 uF VUSB bypass or USB enumeration will fail intermittently. The PPS feature must be unlocked by writing the IOLOCK bit sequence before remapping peripherals, otherwise peripherals will not function after POR.
Place the 32 MHz primary oscillator crystal (or resonator) within 5 mm of the OSCI/OSCO pins with symmetric trace lengths and a ground ring guard trace. Use a star-ground topology tying USB ground, digital ground, and analog ground at a single point near the MCU VSS pins. Keep CTMU touch traces short and guarded to prevent false touches from switching noise. For capacitive touch designs, add a 100 nF series resistor on each touch channel to improve EMI immunity.
Compliance Information
RoHS and REACH compliant per Microchip product page (DS39980 family). The PIC24FJ256GB108 family is not AEC-Q100 qualified - for automotive applications, see PIC24FJ256GB108-I/PT-E (extended temperature) variants. Lead-free reflow profile JEDEC J-STD-020 is supported. Halogen-free status not explicitly stated in provided data and marked unknown.