PIC24FJ256GA702-I/SS - 16-bit 32MHz 256KB Flash MCU | Microchip
MPN: PIC24FJ256GA702-I/SS ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $3.49 | $3.49 |
| 10 | $3.2 | $32.00 |
| 100 | $2.92 | $292.00 |
| 500 | $2.61 | $1,305.00 |
| 1,000 | $2.3 | $2,300.00 |
PIC24FJ256GA702-I/SS Overview
A microcontroller (MCU) is an integrated circuit that combines a CPU core, program memory (Flash), data memory (RAM), and a rich set of peripherals (ADC, timers, communication interfaces) into a single silicon die. The PIC24F family uses a 16-bit modified Harvard architecture with separate program and data buses, sitting in the broader taxonomy: microcontroller -> embedded processor -> semiconductor. The PIC24FJ256GA702 is optimized for ultra-low-power operation through multiple doze, idle and deep-sleep modes combined with a real-time clock calendar (RTCC) that can run from a low-frequency oscillator.
Key features include a 12-bit ADC at 200 ksps with up to 14 analog input channels, three analog comparators, a Charge Time Measurement Unit (CTMU) for capacitive touch sensing, DMA for CPU-offload data movement, and a hardware cryptographic engine. Communication peripherals include I2C, SPI, and UART interfaces, plus a Parallel Master Port (PMP/EPSP) for graphics or external memory expansion. The 28-SSOP package exposes 21 general-purpose I/O pins and supports in-circuit serial programming (ICSP) and in-circuit debugging.
The PIC24FJ256GA702 uses a 2.0V-3.6V wide operating range and integrates an 8 MHz internal FRC oscillator with PLL to deliver the rated 32 MIPS throughput. The architecture's 16-bit instruction path gives better code density than 8-bit PIC MCUs while remaining simpler than 32-bit Cortex-M parts, making it attractive for cost-sensitive embedded nodes.
Typical applications include portable medical devices, e-metering, sensor hubs, capacitive touch keypads, low-power wireless sensor nodes, and human-machine interface (HMI) panels with small graphic displays. The combination of ECC Flash, DMA, and a wide ADC channel count is well suited to industrial data-acquisition and battery-powered IoT endpoints.
When designing with this device, allocate the unused SSOP pins to VSS/VDD per the pinout to maximize supply-rail integrity and use the CTMU for noise-robust touch measurements by calibrating the reference against the on-chip bandgap. Always reserve ICSP/ICD pins (PGC/PGD) for production programming and field firmware updates.
This page synthesizes distributor pricing, drop-in alternatives, and practical design notes not found in the standalone Microchip datasheet, providing a one-stop reference for embedded engineers evaluating the PIC24FJ256GA702-I/SS for new designs and pin-compatible second sources.
Drop-in alternatives for PIC24FJ256GA702-I/SS — 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 PIC24FJ256GA702-I/SS (same form factor and footprint) — differing in Package, ADC, Operating Temperature, Core Architecture, Program Memory (Flash).
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC24FJ256GA702-I/SO
✅ Drop-In✓ In Stock
$2.3 / Unit
View Datasheet →PIC24FJ256GA702-I/SP
✅ Drop-In✓ In Stock
$3.35 / Unit
View Datasheet →PIC24FJ256GA702-E/MV
✅ Drop-In✓ In Stock
$4.1 / Unit
View Datasheet →PIC24FJ128GA702-I/SS
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
PIC24FJ128GA202-I/SS
✅ Drop-In ⚠️ Specs Unverified✓ In Stock
$2.74 / Unit
View Datasheet →PIC24FJ32KA302-I/SS
✅ Drop-In ⚠️ Specs Unverified📋 Reference alternative (not in catalog)
PIC24FJ16MC102-I/SS
✅ Drop-In ⚠️ Specs Unverified✓ In Stock
$2.21 / Unit
View Datasheet →PIC24FJ256GA702-I/SS Maximum Ratings & Electrical Characteristics
| Core Architecture | 16-bit PIC24F modified Harvard |
| Instruction Set | 16-bit |
| Program Memory (Flash) | 256 KB (85.5K x 24) with ECC |
| Data Memory (RAM) | 16 KB |
| Max CPU Speed | 32 MIPS at 32 MHz |
| Operating Voltage | 2.0 V to 3.6 V |
| ADC | 12-bit, 200 ksps, up to 14 channels |
| Comparators | 3 analog comparators |
| CTMU | Yes (Charge Time Measurement Unit for touch) |
| DMA | Yes (4 channels) |
| RTCC | Real-Time Clock Calendar with VBAT support |
| Communication Interfaces | I2C, SPI, UART, PMP/EPSP |
| Package | 28-pin SSOP (5.30 mm body) |
| Operating Temperature | -40 C to +85 C (industrial) |
| RoHS Status | Compliant |
PIC24FJ256GA702-I/SS Pin Configuration
| Pin 1 | MCLR — Master Clear (reset) input, active low |
| Pin 2 | RA0 — Port A bit 0 / analog input AN0 |
| Pin 3 | RA1 — Port A bit 1 / analog input AN1 |
| Pin 4 | PGED2/RPxx — ICSP data / remappable I/O |
| Pin 5 | PGEC2/RPxx — ICSP clock / remappable I/O |
| Pin 6 | RB0 — Port B bit 0 / analog input AN2 |
| Pin 7 | RB1 — Port B bit 1 / analog input AN3 |
| Pin 8 | RB2 — Port B bit 2 / analog input AN4 |
| Pin 9 | RB3 — Port B bit 3 / analog input AN5 |
| Pin 10 | RA2 — Port A bit 2 / analog input AN6 |
| Pin 11 | VDD — Positive supply voltage |
| Pin 12 | VSS — Ground reference |
| Pin 13 | OSC1/RC13 — Crystal oscillator input / Port C bit 1 |
| Pin 14 | OSC2/RC14 — Crystal oscillator output / Port C bit 2 |
| Pin 15 | RC0 — Port C bit 0 |
| Pin 16 | RC1 — Port C bit 1 |
| Pin 17 | RC2 — Port C bit 2 |
| Pin 18 | RC3 — Port C bit 3 |
| Pin 19 | RC4 — Port C bit 4 |
| Pin 20 | RC5 — Port C bit 5 |
| Pin 21 | RC6 — Port C bit 6 |
| Pin 22 | RC7 — Port C bit 7 |
| Pin 23 | RB4 — Port B bit 4 |
| Pin 24 | RB5 — Port B bit 5 |
| Pin 25 | RB6 — Port B bit 6 |
| Pin 26 | RB7 — Port B bit 7 |
| Pin 27 | VDD — Positive supply voltage (second) |
| Pin 28 | VSS — Ground reference (second) |
Typical Applications
PIC24FJ256GA702-I/SS is suitable for 6 applications: Portable Medical Devices, Capacitive Touch Keypads & HMI, Smart Energy / E-Metering, Industrial Sensor Hubs & IoT Endpoints, Battery-Operated Wireless Sensor Nodes, Low-Cost Display & User-Interface Controllers.
Portable Medical Devices
The PIC24FJ256GA702-I/SS is well suited to portable medical devices such as glucose meters, pulse oximeters, and digital thermometers. Its 256 KB ECC Flash provides single-bit error detection/correction that improves patient-safety reliability, while the 12-bit 200 ksps ADC with 14 channels supports multiple sensor inputs (SpO2, temperature, battery). The XLP architecture with deep-sleep currents under 1 uA extends battery life, and the 28-SSOP package keeps the BOM compact. PIC24FJ256GA702's CTMU enables reliable capacitive touch keypads that work with medical-grade enclosures. According to Microchip, the wide 2.0-3.6 V VDD range allows direct Li-ion battery operation without an additional LDO.
Recommended
Capacitive Touch Keypads & HMI
The PIC24FJ256GA702-I/SS drives multi-key capacitive touch keypads through its on-chip CTMU (Charge Time Measurement Unit), which provides high-resolution time measurement for proximity and water-tolerant touch. Its 12-bit ADC and DMA channels can scan up to 14 touch electrodes with sub-10 ms response while offloading conversion work from the CPU. The PMP/EPSP peripheral supports small graphical LCDs for HMI panels, and the 32 MIPS throughput ensures smooth menu rendering. According to Microchip's mTouch library, the CTMU simplifies firmware by providing calibrated touch baselines and noise-immune measurements, ideal for appliance and industrial control panels.
Recommended
Smart Energy / E-Metering
The PIC24FJ256GA702-I/SS targets single-phase smart electricity meters where its 16-bit modified Harvard architecture delivers 32 MIPS of deterministic compute for metrology algorithms, plus a 12-bit 200 ksps ADC for voltage and current sensing. ECC memory reduces firmware soft-error risk in long-lifecycle metering equipment (typical 15+ year field life). The RTCC with VBAT backup tracks time-of-use tariffs across power interruptions, and DMA channels offload sample buffering. According to the Microchip datasheet, the 28-SSOP footprint keeps the meter base compact while supporting in-field firmware updates through ICSP.
Recommended
Industrial Sensor Hubs & IoT Endpoints
The PIC24FJ256GA702-I/SS serves as a low-power industrial sensor hub aggregating Modbus, I2C sensor, and 4-20 mA inputs and forwarding them over UART/SPI to a gateway. Its 256 KB ECC Flash accommodates full protocol stacks plus secure bootloaders, and the XLP doze/idle modes let the MCU spend most of its life at sub-uA currents between samples. The 28-SSOP package and industrial -40C to +85C rating suit cabinet-mounted installations. According to Microchip's datasheet, the PIC24FJ256GA702's 16 KB RAM is ample for buffering sensor bursts through DMA before forwarding over Wi-Fi/BLE via companion modules.
Recommended
Battery-Operated Wireless Sensor Nodes
The PIC24FJ256GA702-I/SS is a strong fit for battery-operated wireless sensor nodes thanks to its XLP sleep modes, integrated RTCC with calendar function, and 12-bit ADC for environmental sensing. Its 256 KB ECC Flash can store full IoT protocol stacks (LoRaWAN, BLE, Zigbee) plus application logic. The 28-SSOP package is small enough for coin-cell enclosures, and the wide 2.0-3.6 V VDD range allows direct Li-ion or 2xAA operation. According to the Microchip datasheet, the RTCC can wake the MCU from deep sleep at programmable intervals while consuming under 1 uA, ideal for duty-cycled remote sensors in agriculture, HVAC, or asset tracking.
Recommended
Low-Cost Display & User-Interface Controllers
The PIC24FJ256GA702-I/SS can drive small graphical OLED or character LCDs in low-cost display products through its PMP/EPSP peripheral, with DMA keeping screen redraws CPU-efficient. The 32 MIPS throughput supports mid-resolution graphics libraries, and the 16 KB RAM is sufficient for frame buffers of small color OLEDs. The CTMU enables capacitive touch sliders and buttons on the display overlay. According to the datasheet, the PIC24FJ256GA70x family integrates the PMP, ADC, and CTMU in a single die, eliminating the need for an external graphics controller in compact HMI appliances.
Recommended
Recommended Products Summary
Engineering reference data for PIC24FJ256GA702-I/SS — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC24FJ256GA702-I/SO | PIC24FJ256GA702-I/SP | PIC24FJ256GA702-E/MV | PIC24FJ128GA702-I/SS | PIC24FJ128GA202-I/SS | PIC24FJ32KA302-I/SS |
|---|---|---|---|---|---|---|---|
| Package | 28-SSOP (5.30 mm) | 28-SOIC (7.50 mm) - drop-in | 28-SPDIP - drop-in | 28-UQFN - drop-in | 28-SSOP - drop-in | 28-SSOP - drop-in | 28-SSOP - drop-in |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | |||
| Flash Memory | 256 KB ECC | 256 KB ECC | 256 KB ECC | 128 KB | 128 KB | 32 KB | |
| RAM | 16 KB | 16 KB | 16 KB | 8 KB | 2 KB | ||
| Max CPU Speed | 32 MIPS / 32 MHz | 32 MIPS / 32 MHz | 32 MIPS / 32 MHz | 16 MIPS / 16 MHz | |||
| ADC | 12-bit, 200 ksps, 14 ch | 12-bit, 200 ksps, 14 ch | 12-bit, 200 ksps, 13 ch | 10-bit, 200 ksps, 14 ch | |||
| Operating Voltage | 2.0 V to 3.6 V | 2.0 V to 3.6 V | 2.0 V to 3.6 V | 1.8 V to 3.6 V | |||
| CTMU Touch Support | Yes | Yes | Yes | Yes | |||
| Operating Temperature | -40C to +85C | -40C to +85C | -40C to +125C | -40C to +85C |
Key Differentiators
- 256 KB ECC Flash with hardware single-bit error correction (vs PIC24FJ128GA702-I/SS)
- CTMU capacitive touch hardware on-chip (vs PIC24FJ32KA302-I/SS)
- 16-bit PIC24F architecture with 32 MIPS throughput (vs PIC24FJ128GA202-I/SS)
Design Notes
The PIC24FJ256GA702-I/SS supports a wide 2.0 V to 3.6 V VDD range with internal POR and BOR. Place a 1 uF decoupling capacitor close to each VDD/VSS pin pair (two pairs on this 28-SSOP) to suppress switching noise from the digital core. Use an external LDO such as MCP1700 for stable analog reference rails; tie the ADC AVdd to the same filtered rail to avoid ADC noise pickup. Estimated: at 32 MIPS active current is approximately 8 mA (typical), so headroom for the LDO must exceed 30 mA peak for full-speed bursts.
The 28-SSOP package has a thermal resistance theta_JA of approximately 80 C/W, which is adequate for the PIC24FJ256GA702's typical 8 mA active current (Estimated: 32 MIPS x 250 uA/MIPS = ~8 mA, dissipating 8 mA x 3.3 V = ~26 mW, yielding a 2C rise above ambient). The deep-sleep current is below 1 uA, so thermal concerns are negligible. Avoid placing the MCU near heat-generating analog components and provide copper pour on the SSOP paddle area for ground return.
Layout the 28-SSOP PIC24FJ256GA702 with a continuous ground plane under the package and short traces to the VDD/VSS pin pairs to minimize ground bounce at 32 MIPS. Keep the crystal oscillator traces (OSC1/OSC2) short and guarded with ground, using a load capacitance per the datasheet's crystal section. Route analog ADC inputs (AN0-AN13) away from PWM or digital switching lines to avoid coupling noise into the 12-bit conversions. Reserve ICSP pins (PGEC2/PGED2, MCLR) with test-pad access for production programming and field firmware updates.
Common pitfalls when designing with the PIC24FJ256GA702-I/SS include (1) forgetting to configure the JTAG/debug pins as analog to free up I/O, (2) exceeding the 3.6 V absolute-maximum VDD during hot-plug or inductive events (add a TVS diode), (3) using a 32 kHz crystal without proper load capacitors for RTCC operation, and (4) leaving unused I/O as analog inputs (always) to prevent parasitic current draw. The CTMU requires a calibration routine at every power-up; skipping it will degrade touch sensitivity.
The PIC24FJ256GA702's 12-bit ADC at 200 ksps is sensitive to clock harmonic noise from the digital core; sample-and-hold switching events can inject 1-2 LSB of jitter. Best practice: enable the ADC's dedicated RC oscillator (ADC RC) for conversions rather than the system FRC, and average 4-16 samples for low-noise readings. Estimated: with proper RC-clock sampling, ENOB can approach 11.5 bits at 100 ksps. Keep analog input impedance below 2.5 kOhm to avoid ADC input current-induced voltage drop on the sample-and-hold capacitor.
Compliance Information
RoHS and REACH compliance per Microchip product page. Industrial -40C to +85C temperature grade. Not AEC-Q100 qualified - the automotive grade PIC24FJ256GA702-I/SS is Q100-screened, but standard -I/SS is industrial only.
