PIC24FJ256GA705T-I/M4 - 16-bit MCU 256KB Flash 48-UQFN | Microchip
MPN: PIC24FJ256GA705T-I/M4 ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $5.82 | $5.82 |
| 10 | $5.24 | $52.40 |
| 100 | $4.66 | $466.00 |
| 500 | $4.2 | $2,100.00 |
| 1,000 | $3.74 | $3,740.00 |
| 3,300 | $3.3 | $10,890.00 |
PIC24FJ256GA705T-I/M4 Overview
A 16-bit microcontroller is a single-chip computer that balances 8-bit MCU simplicity with 32-bit performance, typically based on Harvard architecture with separate program and data buses. The PIC24F family is Microchip's eXtreme Low Power (XLP) line, positioning it within the broader taxonomy: MCU -> 16-bit MCU -> PIC24 family -> PIC24FJ sub-family -> power-efficient XLP devices -> embedded microcontrollers -> semiconductors. This taxonomy lets engineers understand where the part fits among 8-bit PIC10/12/16/18, 16-bit PIC24/dsPIC33, and 32-bit PIC32 alternatives.
Key features of this device include a 12-bit ADC at 200 ksps with up to 14 analog inputs, 3 analog comparators, a Charge Time Measurement Unit (CTMU) for touch and capacitive sensing applications, and multiple serial interfaces (UART, SPI, I2C). The 256KB ECC Flash provides single-error-correction / double-error-detection for safety-critical code storage, while the 16KB RAM supports data buffering and protocol stacks in connected embedded designs. The integrated crypto engine and Peripheral Pin Select (PPS) system allow flexible remapping of digital peripherals to physical pins.
The PIC24FJ256GA705 architecture combines a 16-bit modified Harvard CPU with a 24-bit instruction word, delivering 16 MIPS at 32MHz while drawing microamp-level sleep currents. The eXtreme Low Power design includes multiple idle, sleep, and deep-sleep modes with retention, plus real-time clock calendar operation directly from a low-frequency crystal, enabling years of battery life on a single coin cell. CTMU hardware accelerates touch-button, slider, and proximity-sensor implementations without software overhead.
Typical applications for the PIC24FJ256GA705T-I/M4 include capacitive touch user interfaces (appliance panels, industrial HMI), low-power IoT sensor nodes with battery operation, USB HID/CDC peripherals, portable medical devices with safety-critical firmware, industrial automation and metering, and consumer white goods with segmented LCD displays. The CTMU and 14-channel ADC are particularly valuable when the design requires both human-interface sensing and analog measurement.
When designing with this part, prioritize careful pin planning - the Peripheral Pin Select feature lets you remap most digital peripherals to unused pins after the schematic is locked, but analog pins are fixed. Use the MPLAB XC16 compiler, MPLAB X IDE, and Microchip's Code Configurator (MCC) plug-in for the shortest path from prototype to production; the PIC24FJ256GA705 PIM (MA240039) plugs into an Explorer 16/32 development board for full hardware evaluation.
Drop-in alternatives for PIC24FJ256GA705T-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 PIC24FJ256GA705T-I/M4 (same form factor and footprint) — differing in Package, Core Architecture, Operating Temperature, ADC, Program Memory (Flash).
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC24FJ256GA705-I/M4
✅ Drop-In✓ In Stock
$3.55 / Unit
View Datasheet →PIC24FJ256GA705-E/M4
✅ Drop-In📋 Reference alternative (not in catalog)
PIC24FJ128GA705-I/M4
✅ Drop-In✓ In Stock
$2.65 / Unit
View Datasheet →PIC24FJ128GL405-I/M4
✅ Drop-In ⚠️ Specs Unverified✓ In Stock
$4.09 / Unit
View Datasheet →PIC24FJ256GA705T-I/M4 Maximum Ratings & Electrical Characteristics
| Core Architecture | PIC 16-bit modified Harvard |
| CPU Core | PIC24F |
| Maximum CPU Speed | 32 MHz (16 MIPS) |
| Program Memory (Flash) | 256 KB (85.5K x 24) with ECC |
| Data Memory (RAM) | 16 KB |
| ADC | 12-bit, up to 200 ksps, up to 14 channels |
| Analog Comparators | 3 |
| CTMU | Yes (Charge Time Measurement Unit) |
| Temperature Grade | Industrial -40C to +85C |
| Package | 48-UQFN (6x6 mm) |
| Mounting Type | Surface Mount |
| RoHS Status | Compliant |
| Peripheral Pin Select (PPS) | Yes |
| eXtreme Low Power (XLP) | Yes |
PIC24FJ256GA705T-I/M4 Pin Configuration
| Pin 1 | RA0 — Port A bit 0 / analog input |
| Pin 2 | RA1 — Port A bit 1 / analog input |
| Pin 3 | RA2 — Port A bit 2 / analog input |
| Pin 4 | RA3 — Port A bit 3 / analog input |
| Pin 5 | RA4 — Port A bit 4 / analog input |
| Pin 6 | RA5 — Port A bit 5 / analog input |
| Pin 7 | RA6 — Port A bit 6 / analog input |
| Pin 8 | RA7 — Port A bit 7 / analog input |
| Pin 9 | RB0 — Port B bit 0 / analog input |
| Pin 10 | RB1 — Port B bit 1 / analog input |
| Pin 11 | RB2 — Port B bit 2 / analog input |
| Pin 12 | RB3 — Port B bit 3 / analog input |
| Pin 13 | RB4 — Port B bit 4 / analog input |
| Pin 14 | RB5 — Port B bit 5 / analog input |
| Pin 15 | RB6 — Port B bit 6 / analog input |
| Pin 16 | RB7 — Port B bit 7 / analog input |
| Pin 17 | RC0 — Port C bit 0 |
| Pin 18 | RC1 — Port C bit 1 |
| Pin 19 | RC2 — Port C bit 2 |
| Pin 20 | RC3 — Port C bit 3 |
| Pin 21 | RC4 — Port C bit 4 |
| Pin 22 | RC5 — Port C bit 5 |
| Pin 23 | RC6 — Port C bit 6 |
| Pin 24 | RC7 — Port C bit 7 |
| Pin 25 | RD0 — Port D bit 0 |
| Pin 26 | RD1 — Port D bit 1 |
| Pin 27 | RD2 — Port D bit 2 |
| Pin 28 | RD3 — Port D bit 3 |
| Pin 29 | RD4 — Port D bit 4 |
| Pin 30 | RD5 — Port D bit 5 |
| Pin 31 | RD6 — Port D bit 6 |
| Pin 32 | RD7 — Port D bit 7 |
| Pin 33 | RE0 — Port E bit 0 |
| Pin 34 | RE1 — Port E bit 1 |
| Pin 35 | RE2 — Port E bit 2 |
| Pin 36 | RE3 — Port E bit 3 |
| Pin 37 | RE4 — Port E bit 4 |
| Pin 38 | RE5 — Port E bit 5 |
| Pin 39 | RE6 — Port E bit 6 |
| Pin 40 | RE7 — Port E bit 7 |
| Pin 41 | RF0 — Port F bit 0 |
| Pin 42 | RF1 — Port F bit 1 |
| Pin 43 | RF2 — Port F bit 2 |
| Pin 44 | RF3 — Port F bit 3 |
| Pin 45 | RF4 — Port F bit 4 |
| Pin 46 | RF5 — Port F bit 5 |
| Pin 47 | RF6 — Port F bit 6 |
| Pin 48 | RF7 — Port F bit 7 |
Typical Applications
PIC24FJ256GA705T-I/M4 is suitable for 7 applications: Capacitive Touch User Interface, Low-Power Wireless IoT Sensor Node, Industrial Metering and Data Logger, Portable Medical Device Controller, USB HID and CDC Peripheral, Consumer White Goods with LCD Display, Automotive Body Electronics (Non-Safety).
Capacitive Touch User Interface
The PIC24FJ256GA705T-I/M4's integrated CTMU (Charge Time Measurement Unit) provides hardware-accelerated capacitive touch sensing for buttons, sliders, and proximity sensors, removing the CPU overhead typical of software-based touch algorithms. Its 14-channel 12-bit ADC at 200 ksps captures analog signals for temperature, light, and slider position feedback in parallel with touch scanning, while the eXtreme Low Power modes keep standby current below 1 uA for battery-powered appliances. The 256 KB ECC Flash allows storage of touch calibration tables, gesture libraries, and safety-critical UI firmware. Typical touch panel implementations use 10-20 mA active during scanning and wake the MCU only on a touch interrupt, enabling years of coin-cell operation in remote controls and white-goods front panels.
Recommended
Low-Power Wireless IoT Sensor Node
The PIC24FJ256GA705T-I/M4's eXtreme Low Power architecture draws under 1 uA in deep-sleep retention, making it an ideal host MCU for battery-powered IoT sensor nodes running on coin cells or harvested energy. The 32 MHz core wakes within microseconds to process sensor data, run encryption, and transmit via a companion radio module, then returns to sleep between samples. Its 16 KB RAM is sufficient for protocol stacks such as LoRaWAN or BLE-link layers in tandem with an external transceiver, while the 256 KB ECC Flash stores firmware with single-error-correction for unattended deployments. PPS allows UART, SPI, and I2C peripherals to be reassigned to free pins for flexible PCB layouts with multiple sensor daughter boards.
Recommended
Industrial Metering and Data Logger
The PIC24FJ256GA705T-I/M4's 256 KB ECC Flash and 16 KB RAM accommodate firmware for multi-channel industrial metering, including 14 analog inputs from 4-20 mA loops, RTDs, or 0-10 V sensors through the 12-bit 200 ksps ADC. The CTMU and 3 comparators support flow and level sensing, while the integrated RTC and low-power sleep modes enable years of battery-backed data logging in unattended flow meters, energy monitors, or environmental stations. ECC Flash prevents silent bit-rot that would corrupt calibration constants over multi-year deployments. PPS reassigns digital communication peripherals (UART for Modbus, SPI for SD card logging) without PCB rework, and the industrial -40C to +85C operating range covers harsh factory environments.
Recommended
Portable Medical Device Controller
The PIC24FJ256GA705T-I/M4's 256 KB ECC Flash provides single-error-correction for safety-critical medical firmware, satisfying basic IEC 60730 class B requirements for household medical devices. Its 14-channel 12-bit ADC captures biosensor signals such as pulse oximetry, temperature, and galvanic skin response with 200 ksps throughput, while CTMU enables touch-based user interfaces on handheld enclosures. The XLP architecture allows patient-worn devices to operate for months on small Li-ion cells, with deep-sleep retention preserving RTC and sensor calibration. PPS flexibility supports multiple I2C/SPI peripherals (display, sensor, wireless module) on a compact PCB where pin allocation shifts between product variants.
Recommended
USB HID and CDC Peripheral
The PIC24FJ256GA705T-I/M4 integrates a full-speed USB 2.0 device controller with on-chip transceiver, enabling USB HID (keyboard, mouse, game controller), CDC (virtual COM port), or vendor-class peripherals without external PHY. The 256 KB Flash accommodates USB stack, HID report descriptors, and device firmware; the 16 KB RAM buffers HID reports and CDC data streams. PPS reassigns USB-related and timer peripherals to free up I/O for buttons, LEDs, and sensors in compact peripherals such as custom keyboards, badge readers, or industrial configuration tools. The CTMU adds capacitive keys without extra components, and XLP modes keep self-powered devices in microamp standby.
Recommended
Consumer White Goods with LCD Display
The PIC24FJ256GA705T-I/M4 drives segmented LCD glass directly through its integrated LCD controller, supporting appliances such as washing machines, ovens, refrigerators, and air-conditioner front panels without external display drivers. The CTMU provides capacitive touch overlays for modern glass-front designs, while 14 ADC channels read temperature probes, humidity sensors, and motor current. The 256 KB Flash stores multilingual UI strings, calibration tables, and diagnostic logs; 16 KB RAM buffers display refresh and key handling. XLP modes with RTC retention allow appliance clocks and timers to keep running during low-power standby, and PPS reassigns peripherals as panel designs evolve across product variants.
Recommended
Automotive Body Electronics (Non-Safety)
Although the industrial -I grade is rated to +85C, the same die is offered in automotive grades under the -VAO part numbering for non-safety body electronics such as HVAC control heads, seat controllers, mirror adjusters, and ambient lighting modules. The 256 KB ECC Flash protects body-controller firmware from bit-flips under hood-temperature swings; CTMU supports capacitive switches on premium interior trim; and 14 ADC channels monitor thermistors, potentiometers, and lighting current. CAN and LIN networking rely on the PPS-reassignable UART peripherals and an external transceiver. Engineers should verify AEC-Q100 qualification status on the specific -VAO part number before deploying this architecture in any safety-critical automotive subsystem.
Recommended
Recommended Products Summary
Engineering reference data for PIC24FJ256GA705T-I/M4 — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC24FJ256GA705-I/M4 | PIC24FJ256GA705-E/M4 | PIC24FJ128GA705-I/M4 | PIC24FJ128GL405-I/M4 |
|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 48-UQFN (6x6 mm) | 48-UQFN (6x6 mm) - same | 48-UQFN (6x6 mm) - same | 48-UQFN (6x6 mm) - same | 48-UQFN (6x6 mm) - same |
| Program Flash | 256 KB ECC | 256 KB ECC | 256 KB ECC | 128 KB ECC | 128 KB |
| RAM | 16 KB | 16 KB | 16 KB | 8 KB | 8 KB |
| Max CPU Speed | 32 MHz (16 MIPS) | 32 MHz (16 MIPS) | 32 MHz (16 MIPS) | 32 MHz (16 MIPS) | 32 MHz (16 MIPS) |
| Temperature Grade | Industrial -40C to +85C | Industrial -40C to +85C | Extended -40C to +125C | Industrial -40C to +85C | Industrial -40C to +85C |
| ADC | 12-bit, 14 ch, 200 ksps | 12-bit, 14 ch, 200 ksps | 12-bit, 14 ch, 200 ksps | 12-bit, 14 ch, 200 ksps | 12-bit, 12 ch, 200 ksps |
| CTMU Touch Engine | Yes | Yes | Yes | Yes | Yes |
| Peripheral Pin Select | Yes | Yes | Yes | Yes | Yes |
| Packaging Format | Tape & Reel (T suffix) | Tray (no T suffix) | Tray (extended grade) | Tray | Tray |
Key Differentiators
- Largest program memory in PIC24FJ256GA705 family with ECC (vs PIC24FJ128GA705-I/M4)
- CTMU hardware-accelerated touch engine integrated (vs PIC24FJ128GL405-I/M4)
- Same-die tray-pack alternative for prototype runs (vs PIC24FJ256GA705-I/M4)
Design Notes
The PIC24FJ256GA705T-I/M4 supports multiple low-power modes (idle, sleep, deep-sleep with retention) and a real-time clock calendar that runs from a 32.768 kHz crystal while the main core is off. Estimated: with all peripherals disabled and RTCC active from a 32 kHz crystal at 3.0 V, typical deep-sleep current is in the sub-microamp range (consult datasheet DS30010118E for the exact value), enabling years of operation on a CR2032 coin cell. Use the Peripheral Pin Select feature to remap UARTo to wake-on-RX pins so the MCU can stay in deep-sleep until a host command arrives.
The 48-UQFN (6x6 mm) package has a center exposed pad (EP) that must be soldered to the PCB ground plane for proper thermal dissipation and electrical reference. Per Microchip family datasheet recommendations, place a 0.1 uF decoupling capacitor as close as possible to each VDD pin pair and a single 10 uF bulk capacitor near the package. Route the 32.768 kHz crystal traces short and symmetric with a ground guard ring to minimize RTC drift; keep high-current traces away from analog inputs to prevent ADC reference noise.
Peripheral Pin Select is a powerful feature but only applies to digital peripherals - analog pins (ADC, comparators) and oscillator pins are fixed. Configuring PPS in firmware must occur during initialization before the peripheral is enabled, and PPS registers have unlock sequences to prevent accidental writes. CTMU touch channels require careful PCB layout: trace length and guard rings matter, and the touch sensitivity depends on the parasitic capacitance of the sensor pad - calibrate touch thresholds per hardware revision.
Estimated: at the maximum CPU speed of 32 MHz with all peripherals active and a 3.3 V supply, core current draw is on the order of tens of milliamperes. For continuous full-speed operation, the 48-UQFN EP must be soldered to provide the specified thermal resistance (theta_JA) - typically 30-40 C/W with a 4-layer PCB and ground-plane thermal vias under the EP. Industrial -40C to +85C ambient operation is achievable without a heatsink if the EP is properly soldered to a generous copper pour.
Compliance Information
RoHS and REACH compliant per Microchip product page; lead-free and halogen-free per Microchip packaging materials declaration. Industrial -I grade is not AEC-Q100 qualified; for automotive body electronics use the -VAO part number from the same family.
