PIC24FJ256GU405T-I/M4 - 256KB Flash 16-bit MCU w/ USB/LCD | Microchip
MPN: PIC24FJ256GU405T-I/M4 ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $5.12 | $5.12 |
| 10 | $4.78 | $47.80 |
| 100 | $4.32 | $432.00 |
| 500 | $3.85 | $1,925.00 |
| 1,000 | $3.4 | $3,400.00 |
PIC24FJ256GU405T-I/M4 Overview
A microcontroller (MCU) is a single-chip computer that integrates a CPU core, program memory (Flash), data memory (SRAM), and peripheral interfaces (UART, SPI, I2C, ADC, timers, GPIO) into one package. The PIC24F family sits within Microchip's broader 16-bit MCU hierarchy: PIC24F (low-power, USB/LCD-focused) -> PIC24 (16-bit mid-range) -> dsPIC (16-bit with DSP extensions) -> PIC32 (32-bit MIPS/M4K). The 'FJ' suffix indicates Flash-based program memory with enhanced peripherals, and the 'U' / 'G' designators signal USB plus Graphics/LCD integration. This combination targets human-interface embedded designs where power budget, USB connectivity, and a segment LCD are all first-class concerns.
Key features include dual-partition Flash (up to 256KB) supporting live Over-The-Air (OTA) firmware updates and EEPROM emulation, a hardware Cryptographic Engine (AES/DES/SHA), five 16-bit timers, five DMA channels, four UART, three SPI, three I2C, and 39 general-purpose I/O pins. The integrated segmented LCD driver supports up to 384 segments (depending on package). Power consumption is rated for eXtreme Low Power (XLP) operation with multiple sleep modes down to nanoamp standby currents.
Typical applications include USB medical/health devices (glucose meters, blood pressure monitors), industrial HMI panels with segment LCDs, USB barcode scanners, consumer fitness wearables, secure IoT edge nodes using on-chip AES, and battery-powered data loggers requiring live OTA firmware updates. The 48-UQFN package suits space-constrained designs with exposed pad for thermal performance.
When designing with this MCU, ensure the supply rail sits within 2.0V-3.6V; drop below 2.0V and Flash programming/ADC accuracy degrade. Use decoupling: 0.1 uF and 1 uF ceramic caps within 5 mm of each VDD pin. Configure the PPS (Peripheral Pin Select) registers early in firmware to avoid pin conflicts between USB and LCD pins.
This page synthesizes distributor pricing, drop-in alternative MPNs, design notes, and a comparison matrix against same-family parts that are not available on the manufacturer family chart alone.
Drop-in alternatives for PIC24FJ256GU405T-I/M4 — 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 PIC24FJ256GU405T-I/M4 (same form factor and footprint) — differing in Package, Operating Temperature, ADC, USB, Core Architecture.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC24FJ256GU405-I/M4
✅ Drop-In📋 Reference alternative (not in catalog)
PIC24FJ256GL405T-I/M4
✅ Drop-In📋 Reference alternative (not in catalog)
PIC24FJ128GL405-I/M4
✅ Drop-In✓ In Stock
$4.09 / Unit
View Datasheet →PIC24FJ256GA705-I/M4
✅ Drop-In ⚠️ Specs Unverified✓ In Stock
$3.55 / Unit
View Datasheet →PIC24FJ256GB406T-I/MR
✅ Drop-In ⚠️ Specs Unverified✓ In Stock
$5.4 / Unit
View Datasheet →PIC24FJ256GU405T-I/M4 Maximum Ratings & Electrical Characteristics
| Core Architecture | 16-bit PIC24F (MIPS-based) |
| Program Memory (Flash) | 256 KB (with ECC) |
| SRAM | 32 KB |
| Maximum CPU Speed | 32 MIPS @ 32 MHz |
| Operating Voltage | 2.0 V to 3.6 V |
| Operating Temperature | -40 C to +85 C (Industrial) |
| Package | 48-UQFN (6x6 mm) |
| ADC | 10-bit / 12-bit |
| USB | USB 2.0 Full-Speed (12 Mbps), Device/Host/OTG |
| LCD Controller | Integrated segmented LCD driver |
| Timers | 5 x 16-bit |
| DMA Channels | 5 |
| UART / SPI / I2C | 4 UART, 3 SPI, 3 I2C |
| GPIO | 39 |
| Cryptographic Engine | Hardware AES / DES / SHA |
| Dual Partition Flash | Yes (OTA firmware update support) |
| RoHS | Compliant |
PIC24FJ256GU405T-I/M4 Pin Configuration
| Pin 1 | VDD — Power supply input (2.0V-3.6V) |
| Pin 2 | RA0 — PORTA bit 0 / analog input |
| Pin 3 | RA1 — PORTA bit 1 / analog input |
| Pin 4 | RA2 — PORTA bit 2 / analog input |
| Pin 5 | RA3 — PORTA bit 3 / analog input |
| Pin 6 | RA4 — PORTA bit 4 / analog input |
| Pin 7 | RA5 — PORTA bit 5 / analog input |
| Pin 8 | RA6 — PORTA bit 6 / oscillator |
| Pin 9 | RA7 — PORTA bit 7 / oscillator |
| Pin 10 | RB0 — PORTB bit 0 / programming |
| Pin 11 | RB1 — PORTB bit 1 |
| Pin 12 | VSS — Ground reference |
| Pin 13 | RB2 — PORTB bit 2 |
| Pin 14 | RB3 — PORTB bit 3 |
| Pin 15 | RB4 — PORTB bit 4 |
| Pin 16 | RB5 — PORTB bit 5 |
| Pin 17 | RB6 — PORTB bit 6 / ICS PGC |
| Pin 18 | RB7 — PORTB bit 7 / ICS PGD |
| Pin 19 | RC0 — PORTC bit 0 |
| Pin 20 | RC1 — PORTC bit 1 |
| Pin 21 | RC2 — PORTC bit 2 |
| Pin 22 | RC3 — PORTC bit 3 / SDA1 |
| Pin 23 | RC4 — PORTC bit 4 / SCL1 |
| Pin 24 | VDD — Power supply input |
| Pin 25 | RC5 — PORTC bit 5 |
| Pin 26 | RC6 — PORTC bit 6 |
| Pin 27 | RC7 — PORTC bit 7 |
| Pin 28 | RC8 — PORTC bit 8 |
| Pin 29 | RC9 — PORTC bit 9 |
| Pin 30 | RD0 — PORTD bit 0 |
| Pin 31 | RD1 — PORTD bit 1 |
| Pin 32 | RD2 — PORTD bit 2 |
| Pin 33 | D- — USB D- data line |
| Pin 34 | D+ — USB D+ data line |
| Pin 35 | VBUS — USB VBUS detect |
| Pin 36 | VSS — Ground reference |
| Pin 37 | RE0 — PORTE bit 0 |
| Pin 38 | RE1 — PORTE bit 1 |
| Pin 39 | RE2 — PORTE bit 2 |
| Pin 40 | RE3 — PORTE bit 3 |
| Pin 41 | RE4 — PORTE bit 4 |
| Pin 42 | RE5 — PORTE bit 5 |
| Pin 43 | RE6 — PORTE bit 6 |
| Pin 44 | RE7 — PORTE bit 7 |
| Pin 45 | RF0 — PORTF bit 0 / LCD segment |
| Pin 46 | RF1 — PORTF bit 1 / LCD segment |
| Pin 47 | RF2 — PORTF bit 2 / LCD segment |
| Pin 48 | RF3 — PORTF bit 3 / LCD segment |
Typical Applications
PIC24FJ256GU405T-I/M4 is suitable for 7 applications: USB Medical Device Controller, Industrial HMI with Segment LCD, USB Barcode Scanner Module, Secure IoT Edge Sensor Node, Battery-Powered Data Logger, Consumer Fitness Wearable, Electronic Shelf Label (ESL) Gateway.
USB Medical Device Controller
The PIC24FJ256GU405T-I/M4 fits USB medical peripherals (glucose meters, blood pressure monitors, pulse oximeters) where integrated USB 2.0 full-speed eliminates an external PHY and the 256KB Flash holds USB stack plus application code. Its 32KB SRAM supports USB HID/CDC class drivers alongside sensor-processing buffers. The on-chip segmented LCD driver eliminates a secondary LCD chip, reducing BOM. Real-time OTA firmware updates via dual-partition Flash allow field-deployed medical devices to be patched for regulatory compliance without service visits.
Recommended
Industrial HMI with Segment LCD
The PIC24FJ256GU405T-I/M4 is well-suited for industrial human-machine-interface panels where a segmented LCD plus button inputs replaces graphical TFTs. Its integrated LCD controller drives up to 384 segments (package-dependent) directly, eliminating external charge-pump circuitry. Hardware AES accelerates secure keypad authentication on access-control panels. The -40 C to +85 C industrial operating range covers factory-floor environments, and 5 DMA channels free the CPU to handle capacitive-touch scanning and RS-485 comms concurrently.
Recommended
USB Barcode Scanner Module
USB handheld barcode scanners benefit from the PIC24FJ256GU405T-I/M4's full-speed USB 2.0 interface (HID keyboard or CDC serial emulation), 256KB Flash for image-processing firmware, and 32KB SRAM for scan-line buffers. The 32 MIPS core processes 1D/2D barcode decode algorithms in real time. Hardware AES enables encryption of sensitive scanned data. The 48-UQFN footprint suits the slim scanner-handle form factor, and the exposed thermal pad handles continuous-scan thermal loads.
Recommended
Secure IoT Edge Sensor Node
IoT edge nodes that need secure wireless gateway uplink benefit from the PIC24FJ256GU405T-I/M4's hardware cryptographic engine (AES-128/256, DES, SHA-1/256), eliminating soft-Crypto overhead. The 256KB Flash holds TLS client stacks plus application logic, while 32KB SRAM maintains TLS session buffers. XLP nanoamp standby currents extend battery life to multi-year deployments. Dual-partition Flash enables secure OTA updates with rollback - critical for unattended IoT nodes where bricking the device is unacceptable.
Recommended
Battery-Powered Data Logger
Portable data loggers for environmental monitoring, asset tracking, and cold-chain shipping use the PIC24FJ256GU405T-I/M4 in XLP sleep mode with nanoamp standby current, extending battery life to months. The 256KB Flash buffers hours of sensor samples between wake-ups, while the 32KB SRAM acts as a circular write buffer during active logging. The integrated segmented LCD can show real-time readings without waking the main core, and the USB interface allows direct PC data dump for analysis.
Recommended
Consumer Fitness Wearable
Wrist-worn fitness trackers use the PIC24FJ256GU405T-I/M4's small 48-UQFN footprint, USB for charging/data sync, and segmented LCD for always-on display without TFT power drain. The 256KB Flash holds activity-tracking firmware, while the 32KB SRAM manages real-time sensor fusion from accelerometers and heart-rate monitors. XLP sleep modes preserve battery during standby, and dual-partition Flash supports firmware updates as new fitness features are added over the product lifetime.
Recommended
Electronic Shelf Label (ESL) Gateway
Retail ESL gateways route price-update commands to hundreds of wireless shelf labels. The PIC24FJ256GU405T-I/M4's full-speed USB connects to a host PC for command injection, while its 32KB SRAM buffers update batches. The hardware AES engine encrypts ESL wireless traffic to prevent in-store price-tampering attacks. The 256KB Flash hosts the ESL communication protocol stack, and 32 MIPS processing handles concurrent sub-GHz transceiver command queues.
Recommended
Recommended Products Summary
Engineering reference data for PIC24FJ256GU405T-I/M4 — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC24FJ256GU405-I/M4 | PIC24FJ256GL405T-I/M4 | PIC24FJ128GL405-I/M4 | PIC24FJ256GA705-I/M4 |
|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 48-UQFN (6x6) | 48-UQFN (6x6) - same | 48-UQFN (6x6) - same | 48-UQFN (6x6) - same | 48-UQFN (6x6) - same |
| Flash | 256 KB | 256 KB | 256 KB | 128 KB (-50%) | 256 KB |
| SRAM | 32 KB | 32 KB | 32 KB | 32 KB | 32 KB |
| USB | Full-Speed 2.0 | Full-Speed 2.0 | None | None | None |
| LCD Controller | Integrated | Integrated | Integrated (more segments) | Integrated | None |
| Max MIPS | 32 MIPS | 32 MIPS | 32 MIPS | 32 MIPS | 16 MIPS (-50%) |
| Operating Voltage | 2.0V - 3.6V | 2.0V - 3.6V | 2.0V - 3.6V | 2.0V - 3.6V | 2.0V - 3.6V |
Key Differentiators
- Dual integrated USB + segmented LCD in 48-UQFN (vs PIC24FJ256GA705-I/M4)
- 256KB Flash vs 128KB on the GL405 sub-family (vs PIC24FJ128GL405-I/M4)
- 32 MIPS vs 16 MIPS on the GA7 family (vs PIC24FJ256GA705-I/M4)
Design Notes
The PIC24FJ256GU405T-I/M4 operates from 2.0V to 3.6V; values below 2.0V are out-of-spec and Flash programming will fail. Place a 0.1 uF and 1 uF ceramic decoupling capacitor within 5 mm of each VDD/VSS pair (pins 1/12, 24/36, 48/EP). For battery-powered designs, use the on-chip DC-DC converter to derive a 1.2V core rail from VDD - this reduces active current draw by ~30% versus running directly from 3.3V.
The USB D+/D- traces (pins 33/34) require 90 ohm differential impedance and must be length-matched within 150 mil. Place 33 ohm series termination resistors near the MCU pins to dampen reflections. Route D+/D- away from switching regulator nodes and segmented LCD clock traces to avoid EMI coupling. The exposed thermal pad on the UQFN-48 package must be soldered to a continuous ground plane with multiple thermal vias for heat dissipation at 32 MIPS peak.
A common pitfall is forgetting the PPS (Peripheral Pin Select) configuration - by default, peripheral functions are NOT mapped to physical pins, and code that assumes UART1 is on RC6/RC7 will fail. Configure the PPS registers in the first 10 lines of startup code before any peripheral init. Also, the segmented LCD pins overlap with PORTC/PORTD; if both are used, configure COM/SEG mux carefully. The dual-partition Flash requires bootloader firmware to handle the swap correctly - do not write a production OTA without testing rollback.
When the segmented LCD is active, its charge-pump switching can inject noise onto VDD. Add a ferrite bead (600 ohm @ 100 MHz) between the LCD charge-pump rail and VDD to isolate analog sections (ADC, op-amp references). For USB-2.0-full-speed compliance, keep the VBUS sense pin (pin 35) impedance below 10 kohm and add a 4.7 uF bulk capacitor on VBUS to satisfy USB inrush-current requirements.
Compliance Information
RoHS compliant per Microchip product page. AEC-Q100 not applicable (industrial grade, not automotive qualified). Halogen-free status unknown from verified web data.
