PIC24FJ256GU405-I/PT - 256KB Flash USB MCU | Microchip
MPN: PIC24FJ256GU405-I/PT ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $7.1 | $7.10 |
| 10 | $6.4 | $64.00 |
| 100 | $5.75 | $575.00 |
| 500 | $5.2 | $2,600.00 |
| 1,000 | $4.75 | $4,750.00 |
PIC24FJ256GU405-I/PT Overview
A 16-bit microcontroller (MCU) is a programmable processor that uses a 16-bit data path and instruction word, positioned between 8-bit MCUs (lower power, simpler peripherals) and 32-bit MCUs (higher throughput, richer ecosystems). The PIC24F family from Microchip is engineered for low-power, mixed-signal embedded designs, sitting within the broader hierarchy of microcontrollers -> embedded processors -> semiconductors. The PIC24FJ 'GU4/GL4' family specifically targets applications requiring large memory, USB connectivity, LCD drive, and field upgradability.
Key features of the PIC24FJ256GU405 include 256 KB ECC Flash with dual-partition support for live firmware update, 32 KB SRAM, a hardware Real-Time Clock Calendar (RTCC) with VBAT retention, four 16-bit timers, a 12-bit ADC with up to 200 ksps conversion rate, multiple UART/SPI/I2C peripherals, and CIP blocks such as CLC, MCCP, and PWM. The device operates from 2.0 V to 3.6 V and offers eXtreme Low-Power (XLP) sleep currents in the nanoamp range.
The architecture combines a 16-bit modified Harvard CPU with a 24-bit instruction word and DSP capability (single-cycle MAC), enabling efficient signal processing without burdening the core. Built-in safety features include ECC on Flash, a code-protect lock, a backup oscillator, and a watchdog timer. The 48-pin TQFP (7x7 mm) provides generous I/O for mixed-signal designs.
Typical applications include consumer medical devices (glucometers, blood pressure monitors), portable data loggers, USB peripherals (HID, CDC, vendor-class), industrial HMI with integrated segmented LCD, home automation gateways, and battery-powered IoT sensor nodes. The dual-partition Flash enables remote OTA firmware upgrades without service interruption, ideal for field-deployed equipment.
When designing with this MCU, route the USB D+/D- lines as a 90-ohm differential pair with matched length, keep the VUSB capacitor close to the VUSB pin, and place the 32.768 kHz crystal within 5 mm of SOSCO/SOSCI to minimize load capacitance error. The integrated segmented LCD driver simplifies BOM cost in metering and HMI designs.
This page synthesizes distributor pricing, drop-in alternatives, and practical design notes not found in the manufacturer datasheet alone.
Drop-in alternatives for PIC24FJ256GU405-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 PIC24FJ256GU405-I/PT (same form factor and footprint) — differing in Package, ADC, Core Architecture, USB, Program Memory (Flash).
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC24FJ256GU405-E/PT
✅ Drop-In✓ In Stock
$4.83 / Unit
View Datasheet →PIC24FJ128GU405-I/PT
✅ Drop-In✓ In Stock
$3.25 / Unit
View Datasheet →PIC24FJ256GL405-I/PT
✅ Drop-In✓ In Stock
$2.75 / Unit
View Datasheet →PIC24FJ256GU410-I/PT
✅ Drop-In ⚠️ Specs Unverified✓ In Stock
$4.35 / Unit
View Datasheet →PIC24FJ128GU410-I/PT
✅ Drop-In✓ In Stock
$3.83 / Unit
View Datasheet →PIC24FJ256GU405-I/PT Maximum Ratings & Electrical Characteristics
| Core Architecture | 16-bit PIC24F (modified Harvard, 24-bit instruction word) |
| Maximum CPU Speed | 32 MHz (16 MIPS) |
| Program Memory (Flash) | 256 KB with ECC and dual-partition |
| SRAM | 32 KB |
| USB Controller | USB 2.0 Full-Speed Device/Host/OTG |
| LCD Driver | Integrated segmented LCD controller |
| Supply Voltage (VDD) | 2.0 V to 3.6 V |
| ADC | 12-bit, up to 200 ksps |
| Timers | 5 x 16-bit timers (including RTCC) |
| Communication Peripherals | UART, SPI, I2C, USB |
| Operating Temperature | -40 C to +85 C (Industrial) |
| Package | 48-pin TQFP (7x7 mm) |
| Mounting Type | Surface Mount |
| MSL Level | 3 (168 hours) |
| RoHS Status | Compliant |
PIC24FJ256GU405-I/PT 48-pin tqfp (7x7 mm) Pin Configuration Guide
Pin configuration for PIC24FJ256GU405-I/PT (48-pin tqfp (7x7 mm) package). This digital IC includes GPIO, communication interfaces (UART, SPI, I2C), and power pins. Refer to the manufacturer datasheet for alternate pin functions and configuration options. Essential for embedded system design and PCB layout.
No detailed pinout data available for PIC24FJ256GU405-I/PT.
Refer to the datasheet for full pin configuration.
Typical Applications
PIC24FJ256GU405-I/PT is suitable for 6 applications: Consumer Medical Devices, Industrial HMI with Segmented LCD, USB HID / CDC Peripherals, Portable Data Loggers, Home Automation Gateways, Battery-Powered IoT Sensor Nodes.
Consumer Medical Devices
The PIC24FJ256GU405-I/PT is well suited for battery-powered consumer medical devices such as blood-pressure monitors, glucometers, pulse oximeters, and digital thermometers. Its 12-bit ADC at 200 ksps digitizes sensor signals (pressure transducers, photodiodes) with adequate resolution, while the 32 KB SRAM accommodates data logging and waveform buffers. The integrated segmented LCD driver directly drives the front-panel display without an external driver IC, reducing BOM cost. XLP (eXtreme Low-Power) sleep modes drop standby current to nanoamp levels, enabling multi-year battery life on 2x AA cells. According to Microchip application notes, the dual-partition Flash allows secure OTA firmware updates for compliance with evolving medical device regulations. USB OTG enables direct connection to a PC for data download and charging without a separate interface IC.
Recommended
Industrial HMI with Segmented LCD
For industrial human-machine interface panels (process controllers, scales, access control terminals), the PIC24FJ256GU405-I/PT combines a 16-bit core with an on-chip segmented LCD driver capable of driving up to several hundred LCD segments. The 256 KB ECC Flash stores multilingual UI strings, calibration data, and graphics bitmaps without external memory. Five 16-bit timers drive PWM backlight control, buzzer tones, and keypad scanning. The RTCC (Real-Time Clock Calendar) with VBAT retention timestamps events even on main power loss. Industrial temperature range (-40C to +85C) and ECC Flash with code-protect lock meet factory-floor reliability requirements. According to Microchip's datasheet, the 12-bit ADC handles analog sensor inputs (4-20 mA, 0-10 V via front-end) for process control loops.
Recommended
USB HID / CDC Peripherals
The PIC24FJ256GU405-I/PT is ideal for USB Human Interface Device (HID) peripherals such as industrial keypads, barcode scanners, and vendor-class instruments. Its USB 2.0 Full-Speed OTG controller eliminates the need for an external PHY, and Microchip's free MLA / Harmony USB stacks provide ready-made HID, CDC (virtual COM port), and vendor-class firmware, dramatically reducing development time. The 32 KB SRAM accommodates HID report buffers and USB endpoint descriptors, while the 32 MHz / 16 MIPS core handles USB protocol and application tasks simultaneously. According to Microchip's USB design guide, the on-chip pull-up resistors and full-speed transceiver simplify the schematic to just a USB connector, ferrite bead, and decoupling capacitors - a true 2-layer PCB design.
Recommended
Portable Data Loggers
For battery-powered data loggers (cold-chain temperature recorders, environmental monitors, asset trackers), the PIC24FJ256GU405-I/PT provides 256 KB of Flash for event buffering, 32 KB of SRAM for sample arrays, and eXtreme Low-Power sleep modes that drop quiescent current into the nanoamp range. The RTCC with VBAT retention timestamps each sample even on main-battery removal. The 12-bit ADC captures analog sensors (thermistors, load cells, 4-20 mA loops) at 200 ksps with cycle-by-cycle accuracy. Dual-partition Flash enables field firmware upgrades via OTA, critical for compliance with evolving data-integrity standards. According to Microchip application notes, deep sleep + RTCC wake can achieve sub-10 microamp average current, supporting multi-year deployments on a single coin cell.
Recommended
Home Automation Gateways
The PIC24FJ256GU405-I/PT serves as a low-cost sub-GHz or Wi-Fi gateway controller in home automation hubs, bridging RF sensor networks (Zigbee, LoRa, proprietary) to Ethernet or Wi-Fi backhaul. Its USB OTG port can host a Wi-Fi dongle or Ethernet adapter, while multiple UART/SPI/I2C interfaces connect to RF transceivers and sensors. The 256 KB Flash and 32 KB SRAM accommodate protocol stacks (TLS, MQTT client) and translation logic between protocols. The 16-bit DSP engine (single-cycle MAC) efficiently handles encryption/authentication on small packets. According to Microchip's IoT reference designs, OTA updates via dual-partition Flash allow the gateway to be field-upgraded with new device support without bricking.
Recommended
Battery-Powered IoT Sensor Nodes
For wireless IoT sensor nodes in smart agriculture, smart metering, and building automation, the PIC24FJ256GU405-I/PT offers eXtreme Low-Power (XLP) operation, integrated 12-bit ADC, segmented LCD driver for local display, and 256 KB Flash for OTA-capable firmware. Its nanoamp-level sleep current enables multi-year battery life on 2x AA cells when paired with low-power RF modules. The USB OTG port enables convenient configuration and firmware loading during manufacturing or field service. According to Microchip's low-power design guide, combining sleep mode with RTCC wake-up can achieve average currents below 10 microamp at 1 Hz sample rates. The dual-partition Flash allows secure, reliable firmware updates essential for large-scale IoT deployments.
Recommended
Recommended Products Summary
Engineering reference data for PIC24FJ256GU405-I/PT — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC24FJ256GU405-E/PT | PIC24FJ128GU405-I/PT | PIC24FJ256GL405-I/PT | PIC24FJ256GU410-I/PT | PIC24FJ128GU410-I/PT |
|---|---|---|---|---|---|---|
| Package | 48-TQFP (7x7 mm) | 48-TQFP (7x7 mm) - same | 48-TQFP (7x7 mm) - same | 48-TQFP (7x7 mm) - same | 48-TQFP (7x7 mm) - same | 48-TQFP (7x7 mm) - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Core Architecture | 16-bit PIC24F | 16-bit PIC24F - same | 16-bit PIC24F - same | 16-bit PIC24F - same | 16-bit PIC24F - same | 16-bit PIC24F - 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 | 32 MHz (16 MIPS) - same |
| Flash Memory | 256 KB | 256 KB - same | 128 KB (-50%) | 256 KB - same | 256 KB - same | 128 KB (-50%) |
| SRAM | 32 KB | 32 KB - same | 32 KB - same | 32 KB - same | 32 KB - same | 32 KB - same |
| USB Controller | USB 2.0 FS OTG | USB 2.0 FS OTG - same | USB 2.0 FS OTG - same | No USB | USB 2.0 FS OTG - same | USB 2.0 FS OTG - same |
| LCD Driver | Yes (segmented) | Yes - same | Yes - same | Yes - same | Yes - same | Yes - same |
| Operating Temperature | -40C to +85C | -40C to +125C | -40C to +85C - same | -40C to +85C - same | -40C to +85C - same | -40C to +85C - same |
Key Differentiators
- Dual-partition Flash for live OTA firmware updates (vs PIC24FJ128GU405-I/PT)
- Integrated USB 2.0 Full-Speed OTG controller (vs PIC24FJ256GL405-I/PT)
- Industrial temperature grade (-40C to +85C) standard (vs PIC24FJ256GU405-E/PT)
Design Notes
Route USB D+ and D- as a 90-ohm differential pair with matched length (delta less than 2 mm). Keep the VUSB capacitor within 5 mm of the VUSB pin, and place the ferrite bead on VBUS close to the connector. According to Microchip USB design guidelines, the impedance-controlled region must be referenced to a continuous ground plane on layer 2; avoid splits or ground voids under the USB traces. ESD protection (e.g. USBLC6) should be placed as close to the connector as possible.
Place 100 nF decoupling capacitors as close as possible to each VDD/VDDCORE pin pair, with an additional 10 uF bulk capacitor at the regulator output. For XLP sleep modes, ensure all unused I/O pins are configured as analog (high-impedance) to minimize leakage; a single floating digital input can add 1-5 uA per pin. According to Microchip's XLP design guide, selecting the deep-sleep current source (DS_WAKE) and disabling the RTCC can drop standby below 100 nA.
The PIC24FJ256GU405 operates from 2.0 V to 3.6 V - do NOT power it from 5 V. Configure the dual-partition Flash correctly before enabling OTA updates; setting CONFIG3.FBSDO without proper boot sequence can brick the device. When using the integrated LCD driver, allocate enough bias and segment pins - misuse will result in dim or flickering display. According to Microchip errata, early revision silicon had USB suspend-current issues resolved in revision A3; verify the silicon revision when debugging power-related USB issues.
Compliance Information
RoHS and REACH compliant per Microchip product page. Not AEC-Q100 qualified - choose automotive-qualified PIC24FJ variants for AEC-Q100 designs.
