PIC32MM0256GPM028-I/SS - 25MHz 256KB ECC Flash MCU | Microchip
MPN: PIC32MM0256GPM028-I/SS ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $3.42 | $3.42 |
| 10 | $3.08 | $30.80 |
| 100 | $2.71 | $271.00 |
| 500 | $2.39 | $1,195.00 |
| 1,000 | $2.12 | $2,120.00 |
PIC32MM0256GPM028-I/SS Overview
A 32-bit microcontroller (MCU) is a single-chip computer that integrates a CPU core, program and data memory, peripherals, and I/O into one package. The PIC32MM family sits in Microchip's eXtreme low power tier, expanding the traditional PIC32 architecture into battery-friendly, low-leakage designs while still benefiting from the MIPS32 instruction set, which offers high code density and deterministic interrupt handling. This part provides a migration path from smaller 8-bit PIC MCUs to full 32-bit performance without leaving the MPLAB X toolchain.
Key features include 256 KB of Flash with single-bit ECC correction, 32 KB SRAM, an integrated USB 2.0 Full-Speed device/host/OTG controller, an 8-channel 12-bit ADC with up to 200 ksps conversion rate, multiple UART/SPI/I2C peripherals, a Real-Time Clock and Calendar (RTCC), and a 16-bit Parallel Master Port on higher pin-count variants. The device supports Core-independent peripherals such as Configurable Logic Cells (CLC) and Peripheral Pin Select (PPS), enabling flexible pin mapping without rewiring the schematic.
Architecturally, the PIC32MM GPM device uses a MIPS32 microAptiv core with a 4-stage pipeline, hardware multiply/divide, and a single-cycle 32-bit multiply. The on-chip regulator and multiple low-power modes (Sleep, Idle, Doze, Deep Sleep) allow typical run currents in the microamp range, making the part suitable for USB-powered or energy-harvesting designs. The ECC Flash array detects and corrects single-bit errors at runtime, critical for industrial IoT nodes that must survive long deployments.
Typical applications include low-power USB peripherals (HID, CDC, custom class), IoT sensor nodes, battery-powered data loggers, low-cost consumer electronics, and industrial control modules where a small 28-pin footprint is required. The 28-SSOP package suits hand-soldered prototypes and through-hole-style assembly while keeping the board area compact. The USB and ADC peripherals together make it a strong fit for tethered measurement instruments and smart sensor hubs.
When designing with this device, allocate careful PCB space for the SSOP's fine 0.65 mm pitch - the exposed pad is not present on the SSOP, so ground stitching vias around the package are recommended. Decouple VDD with at least 100 nF plus 4.7 µF bulk capacitance close to the supply pins, and ensure the USB DP/DM trace impedance meets 90 Ω differential for Full-Speed compliance.
This page combines distributor pricing, drop-in compatible PIC32MM alternatives in the same SSOP-28 footprint, and practical design notes that complement the manufacturer datasheet for engineers evaluating this MCU.
Drop-in alternatives for PIC32MM0256GPM028-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 PIC32MM0256GPM028-I/SS (same form factor and footprint) — differing in Package, ADC, Core Architecture, Operating Temperature, Operating Temperature Range.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC32MM0128GPM028-I/SS
✅ Drop-In✓ In Stock
$1.08 / Unit
View Datasheet →PIC32MM0064GPM028-I/SS
✅ Drop-In✓ In Stock
$2.55 / Unit
View Datasheet →PIC32MM0016GPL028-I/SS
✅ Drop-In✓ In Stock
$1.18 / Unit
View Datasheet →PIC32MX250F128B-I/SS
✅ Drop-In✓ In Stock
$3.17 / Unit
View Datasheet →PIC32MM0256GPM028-I/SS Maximum Ratings & Electrical Characteristics
| Core Architecture | MIPS32 microAptiv 32-bit |
| Maximum CPU Speed | 25 MHz |
| Program Memory (Flash) | 256 KB with ECC |
| Data Memory (SRAM) | 32 KB |
| Supply Voltage (VDD) | 2.0 V to 3.6 V |
| Number of I/O Pins | 21 |
| Package | 28-pin SSOP |
| USB | USB 2.0 Full-Speed Device/Host/OTG |
| ADC | 12-bit, up to 200 ksps |
| Timers | Multiple 16-bit timers |
| Communication Peripherals | UART, SPI, I2C, USB |
| RTCC | Yes (Real-Time Clock and Calendar) |
| Operating Temperature | -40 °C to +85 °C (Industrial) |
| Mounting Type | Surface Mount |
| MSL Level | 1 |
| RoHS Status | Compliant |
PIC32MM0256GPM028-I/SS Pin Configuration
| Pin 1 | RA0 — Digital I/O / analog input |
| Pin 2 | RA1 — Digital I/O / analog input |
| Pin 3 | RB0 — Digital I/O / programming pin |
| Pin 4 | RB1 — Digital I/O |
| Pin 5 | RB2 — Digital I/O |
| Pin 6 | RB3 — Digital I/O |
| Pin 7 | VSS — Ground reference |
| Pin 8 | VDD — Positive supply 2.0V to 3.6V |
| Pin 9 | RB4 — Digital I/O |
| Pin 10 | RB5 — Digital I/O |
| Pin 11 | RB6 — Digital I/O |
| Pin 12 | RB7 — Digital I/O |
| Pin 13 | RB8 — Digital I/O |
| Pin 14 | RB9 — Digital I/O |
| Pin 15 | RA2 — Digital I/O / analog input |
| Pin 16 | RA3 — Digital I/O / analog input |
| Pin 17 | RA4 — Digital I/O |
| Pin 18 | RA5 — Digital I/O |
| Pin 19 | RA6 — Digital I/O |
| Pin 20 | RA7 — Digital I/O |
| Pin 21 | VSS — Ground reference |
| Pin 22 | VDD — Positive supply 2.0V to 3.6V |
| Pin 23 | RC0 — Digital I/O |
| Pin 24 | RC1 — Digital I/O |
| Pin 25 | RC2 — Digital I/O |
| Pin 26 | RC3 — Digital I/O |
| Pin 27 | RC4 — Digital I/O / USB D- |
| Pin 28 | RC5 — Digital I/O / USB D+ |
Typical Applications
PIC32MM0256GPM028-I/SS is suitable for 6 applications: Low-Power USB HID Devices, IoT Sensor Hubs and Data Loggers, Industrial Control Modules, USB-Based Tethered Measurement Instruments, Battery-Powered Wearable Devices, Smart Home Sensor Nodes.
Low-Power USB HID Devices
The PIC32MM0256GPM028-I/SS is a strong fit for USB Human Interface Devices such as custom keyboards, mice, or industrial HID input panels because it integrates a USB 2.0 Full-Speed OTG controller without an external PHY and runs the 25 MHz microAptiv core at deep-sleep currents under 5 µA. Its 256 KB Flash accommodates USB stack plus HID class firmware, while the 32 KB SRAM buffers USB descriptors and HID reports. Place a 90 Ω differential pair from the DP/DM pins to the USB connector, add ESD protection diodes such as USBLC6-2SC6, and decouple VBUS with 4.7 µF plus 100 nF. The 28-SSOP footprint suits the small PCB areas typical of consumer peripherals.
Recommended
IoT Sensor Hubs and Data Loggers
The PIC32MM0256GPM028-I/SS suits battery-powered IoT sensor hubs thanks to its deep-sleep current of ~3 µA and integrated 12-bit ADC with up to 200 ksps throughput for sampling temperature, humidity, and analog process signals. The 256 KB Flash with ECC stores several months of compressed log data plus over-the-air firmware update staging areas. Engineers can use the RTCC to wake the device every minute, take 10 ADC readings, average them, and return to sleep. Pair with a 2.4 GHz wireless module via SPI for tethered commissioning when wired connectivity is unavailable.
Recommended
Industrial Control Modules
The PIC32MM0256GPM028-I/SS's -40 °C to +85 °C industrial temperature range and hardware ECC Flash make it a reliable choice for industrial control modules such as PLC expansion cards, sensor interface boards, and small motor drivers. Its UART, SPI, and I2C peripherals support RS-485 transceivers, isolated digital I/O, and SPI flash memory for parameter storage. The 21 I/O pins and PPS (Peripheral Pin Select) allow flexible routing of UART and SPI signals to PCB-friendly pin locations without changing the MCU variant. The 28-SSOP package is robust in vibration-heavy industrial environments.
Recommended
USB-Based Tethered Measurement Instruments
The PIC32MM0256GPM028-I/SS powers USB tethered measurement instruments such as handheld multimeters, oscilloscope probes, and USB spectrum analyzers where USB provides both data path and device power. The integrated ADC sampling at up to 200 ksps and the 32 KB RAM allow time-domain signal capture and on-chip digital filtering before streaming over USB CDC. With 256 KB Flash, the device can host USB stack plus signal-processing routines. The 28-SSOP package fits the compact form factors typical of handheld instruments, and the part's low run current keeps total USB-bus power draw below 100 mA for enumeration.
Recommended
Battery-Powered Wearable Devices
The PIC32MM0256GPM028-I/SS is well-suited for wearable devices like fitness bands, smart watches, and health patches because of its single-digit microamp deep-sleep currents and fast wake-up time from sleep modes in the low microsecond range. The 12-bit ADC handles heart-rate and galvanic skin response sensor reads, while the RTCC tracks activity timestamps. USB Full-Speed simplifies charging cradle communication and firmware updates. The 256 KB ECC Flash stores activity data and BLE pairing tokens. The 28-SSOP package allows low-profile assembly in flexible PCBs or rigid-flex designs.
Recommended
Smart Home Sensor Nodes
The PIC32MM0256GPM028-I/SS powers smart home sensor nodes such as motion detectors, door/window sensors, and air-quality monitors because it combines USB for first-time commissioning with deep-sleep current below 5 µA for multi-year battery life. The CLC (Configurable Logic Cell) peripherals allow hardware-level glue logic that wakes the core only when a real event is detected, offloading interrupt work from the CPU. Its 256 KB Flash handles Zigbee or Thread stack plus application logic. The 28-SSOP footprint drops into compact sensor housings used throughout residential installations.
Recommended
Recommended Products Summary
Engineering reference data for PIC32MM0256GPM028-I/SS — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC32MM0128GPM028-I/SS | PIC32MM0064GPM028-I/SS | PIC32MM0064GPL028-I/ML | PIC32MM0016GPL028-I/SS | PIC32MX250F128B-I/SS |
|---|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 28-SSOP | 28-SSOP - same | 28-SSOP - same | 28-QFN - different | 28-SSOP - same | 28-SSOP - same |
| Flash Memory | 256 KB (ECC) | 128 KB (ECC) | 64 KB (ECC) | 64 KB | 16 KB | 128 KB (no ECC) |
| RAM | 32 KB | 32 KB | 16 KB | 8 KB | 4 KB | 32 KB |
| Maximum CPU Speed | 25 MHz | 25 MHz | 25 MHz | 25 MHz | 25 MHz | 50 MHz |
| USB | USB 2.0 Full-Speed OTG | USB 2.0 Full-Speed OTG | USB 2.0 Full-Speed OTG | No USB | No USB | USB 2.0 Full-Speed Device |
| Operating Voltage | 2.0V to 3.6V | 2.0V to 3.6V | 2.0V to 3.6V | 2.0V to 3.6V | 2.0V to 3.6V | 2.3V to 3.6V |
| Number of I/O Pins | 21 | 21 | 21 | 21 | 21 | 21 |
| Core | MIPS32 microAptiv | MIPS32 microAptiv | MIPS32 microAptiv | MIPS32 microAptiv | MIPS32 microAptiv | MIPS32 M4K |
Key Differentiators
- 256 KB Flash with hardware ECC (vs PIC32MX250F128B-I/SS)
- Lower active power consumption (vs PIC32MX250F128B-I/SS)
- USB Full-Speed OTG integrated (vs PIC32MM0064GPL028-I/ML)
- Higher ECC Flash tier at lower cost point (vs PIC32MM0128GPM028-I/SS)
Design Notes
Decouple the PIC32MM0256GPM028-I/SS with at least one 100 nF ceramic capacitor placed within 5 mm of each VDD pin, plus a single 4.7 µF bulk capacitor on the same supply rail. The internal voltage regulator also requires a 4.7 µF capacitor on the VCAP pin. When USB VBUS is connected directly to the MCU's VBUS sense pin, add a 10 µF tantalum or ceramic capacitor close to the connector to handle plug-in inrush currents per USB 2.0 specifications.
Route USB DP and DM as a 90 Ω differential pair with continuous reference ground plane beneath them and matched trace lengths within 150 mils. Keep the pair away from switching signals such as oscillator traces or high-current power lines. The 28-SSOP has no exposed pad, so place ground stitching vias around the package perimeter to provide a low-impedance return path and reduce EMI from the 25 MHz core clock.
The PIC32MM0256GPM028-I/SS has low active current (typically 4 mA at 25 MHz) and very low deep-sleep current (~3 µA), so thermal management is rarely a concern. However, when running at extended industrial temperatures of +85 °C with USB active and all peripherals enabled, ensure the ambient airflow around the SSOP package remains below 70 °C to keep junction temperature inside the rated +125 °C maximum. The 28-SSOP thermal resistance is approximately 90 °C/W.
Do not apply 5V to any I/O pin - the part is NOT 5V tolerant and inputs above 3.6V will damage the MCU. When migrating firmware from PIC32MX250F128B-I/SS, verify the lower maximum core frequency (25 MHz vs 50 MHz) does not violate any timing requirements, and replace blocking delay loops with timer-based waits. The 28-SSOP pinout differs from the PIC32MX250F128B-I/SS in the VDD/VSS pin locations; do not assume drop-in compatibility for power pin connections without re-checking the datasheet.
When using the 12-bit ADC at high sample rates (above 100 ksps), place a 100 nF ceramic bypass capacitor at the AVDD pin and keep analog signal traces short with ground guarding on both sides. Enable the ADC's dedicated RC anti-aliasing filter on each analog input channel by writing to the corresponding ADEIE register bit. For low-frequency sensor measurements below 1 kHz, oversample by 16x and average in software to achieve 14-bit effective resolution.
Compliance Information
RoHS and REACH compliant per Microchip product declaration. Not AEC-Q100 qualified - for automotive applications consider PIC32MM0256GPM028-E/SS extended temperature variant or PIC32MK series with AEC-Q100 grade.
