PIC32MX254F128BT-I/MM - 32-bit 72MHz MCU, 128KB Flash | Microchip
MPN: PIC32MX254F128BT-I/MM ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $5.2 | $5.20 |
| 10 | $4.78 | $47.80 |
| 100 | $4.12 | $412.00 |
| 500 | $3.65 | $1,825.00 |
| 1,000 | $3.2 | $3,200.00 |
PIC32MX254F128BT-I/MM Overview
A PIC32MX microcontroller is a 32-bit MIPS-based MCU family from Microchip that bridges the gap between 8-bit PIC16/PIC24 devices and 32-bit ARM Cortex-M parts. Positioned in the hierarchy: PIC32MX -> PIC32 family -> 32-bit MCU -> microcontroller -> embedded controller. These parts offer deterministic interrupt latency, mature MPLAB XC32 toolchain support, and rich peripherals (USB, CAN, PMP, ADC, CTMU) for cost-sensitive embedded designs.
Key features include MIPS32 M4K single-core at 72 MHz, 128 KB Flash, 32 KB SRAM, full-speed USB 2.0 device/host/OTG, up to 17 general-purpose I/O pins with Peripheral Pin Select (PPS), 10-bit 1 Msps ADC with up to 13 channels, three analog comparators, two I2S/SPI modules, two UART/I2C modules, CTMU for capacitive touch, RTCC, and on-chip temperature measurement. XLP technology provides deep-sleep currents in the microamp range.
The architecture combines a 5-stage MIPS32 M4K pipeline with single-cycle multiply, hardware divide, and 1.5 DMIPS/MHz efficiency. Programmable Peripheral Pin Select remaps digital peripherals to any GPIO, simplifying PCB routing. The 28-pin QFN-S package with exposed pad enables low-thermal-resistance mounting for industrial-temperature operation.
Typical applications include consumer USB devices (HID, CDC, mass storage), low-power IoT sensor nodes, capacitive touch interfaces using CTMU, battery-powered medical monitors, industrial control panels, and home appliances. The USB 2.0 FS peripheral makes the part a strong fit for any design that needs a tethered PC interface without an external PHY.
When designing, use the MPLAB X IDE + XC32 compiler and program via ICSP (PGECx/PGEDx) or the standard 6-pin header. The exposed pad must be soldered to the ground plane for thermal performance and electrical reference. Plan USB DP/DN trace impedance to 90 ohm differential per USB 2.0 spec.
This page synthesizes distributor pricing, drop-in alternatives, and practical design notes not found in the manufacturer datasheet alone.
Drop-in alternatives for PIC32MX254F128BT-I/MM — 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 PIC32MX254F128BT-I/MM (same form factor and footprint) — differing in Operating Temperature, Package, ADC, Core Architecture, DMA Channels.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC32MX254F128B-I/MM
✅ Drop-In📋 Reference alternative (not in catalog)
PIC32MX154F128BT-I/MM
✅ Drop-In📋 Reference alternative (not in catalog)
PIC32MX250F128BT-I/MM
✅ Drop-In📋 Reference alternative (not in catalog)
PIC32MX174F256BT-I/MM
✅ Drop-In📋 Reference alternative (not in catalog)
PIC32MX170F256BT-I/MM
✅ Drop-In📋 Reference alternative (not in catalog)
PIC32MX130F128H-I/MR
✅ Drop-In ⚠️ Specs Unverified✓ In Stock
$3.05 / Unit
View Datasheet →PIC32MX254F128BT-I/MM Maximum Ratings & Electrical Characteristics
| Core Architecture | MIPS32 M4K |
| Core Size | 32-bit single-core |
| Maximum CPU Clock | 72 MHz |
| Performance | 83 DMIPS |
| Program Memory (Flash) | 128 KB (128K x 8) |
| SRAM | 32 KB |
| Operating Voltage | 2.5 V to 3.6 V |
| Number of I/O Pins | 17 |
| Package | 28-QFN-S (6x6 mm) with exposed pad |
| USB | USB 2.0 Full-Speed (Device/Host/OTG) |
| ADC | 10-bit, up to 1 Msps |
| Analog Comparators | 3 |
| Operating Temperature | -40 C to +85 C (Industrial) |
| Mounting Type | Surface Mount |
| MSL Level | 1 (unlimited) |
PIC32MX254F128BT-I/MM Pin Configuration
| Pin 1 | RA0 — General purpose I/O / analog input AN0 |
| Pin 2 | RA1 — General purpose I/O / analog input AN1 |
| Pin 3 | RB0 — General purpose I/O / PGED1 (programming data) |
| Pin 4 | RB1 — General purpose I/O / PGEC1 (programming clock) |
| Pin 5 | RB2 — General purpose I/O / USB D- |
| Pin 6 | RB3 — General purpose I/O / USB D+ |
| Pin 7 | VDD — Positive supply voltage (2.5 V to 3.6 V) |
| Pin 8 | VSS — Ground reference |
| Pin 9 | OSC1 — External oscillator input / crystal connection |
| Pin 10 | OSC2 — External oscillator output / crystal connection |
| Pin 11 | RB4 — General purpose I/O / SOSCO (secondary oscillator out) |
| Pin 12 | RB5 — General purpose I/O / SOSCI (secondary oscillator in) |
| Pin 13 | RB6 — General purpose I/O / PGED2 (programming data) |
| Pin 14 | RB7 — General purpose I/O / PGEC2 (programming clock) |
| Pin 15 | RB8 — General purpose I/O |
| Pin 16 | RB9 — General purpose I/O |
| Pin 17 | RB10 — General purpose I/O |
| Pin 18 | RB11 — General purpose I/O |
| Pin 19 | RC0 — General purpose I/O |
| Pin 20 | RC1 — General purpose I/O |
| Pin 21 | RC2 — General purpose I/O |
| Pin 22 | RC3 — General purpose I/O |
| Pin 23 | RC4 — General purpose I/O |
| Pin 24 | RC5 — General purpose I/O |
| Pin 25 | RC6 — General purpose I/O |
| Pin 26 | RC7 — General purpose I/O |
| Pin 27 | RC8 — General purpose I/O |
| Pin 28 | VUSB — USB internal transceiver supply (3.3 V typical) |
| Pin EP | EP — Exposed thermal pad, must be soldered to VSS plane |
Typical Applications
PIC32MX254F128BT-I/MM is suitable for 7 applications: USB HID / CDC Device, Capacitive Touch Interface (CTMU), Battery-Powered IoT Sensor Node, Industrial Control Panel, Medical Point-of-Care Monitor, Home Appliance with USB Diagnostics, USB Audio / MIDI Device.
USB HID / CDC Device
The PIC32MX254F128BT-I/MM's on-chip USB 2.0 Full-Speed transceiver with device/host/OTG support makes it ideal for USB HID peripherals, CDC virtual COM ports, and MSD devices. The 72 MHz MIPS32 M4K core at 83 DMIPS comfortably handles USB polling plus application code without DMA. Typical designs need only a 90 ohm differential pair on D+/D-, ESD protection array (such as USBLC6-2SC6), and 100 nF decoupling on VBUS. Microchip's MLA USB stack provides ready-to-use HID, CDC, and MSD class drivers for MPLAB X.
Recommended
Capacitive Touch Interface (CTMU)
The integrated Charge Time Measurement Unit (CTMU) plus 10-bit ADC at 1 Msps lets the PIC32MX254F128BT-I/MM implement up to 17 capacitive touch buttons or sliders without an external touch IC. CTMU delivers charge-time resolution down to 1 ns, enabling reliable touch through 3-5 mm glass or plastic overlays. The 72 MHz core runs the touch-scan state machine plus UI rendering on small TFTs via PMP. mTouch reference designs from Microchip shorten time to prototype for white goods and consumer control panels.
Recommended
Battery-Powered IoT Sensor Node
XLP (eXtreme Low Power) technology gives the PIC32MX254F128BT-I/MM deep-sleep currents in the microamp range with retention RAM and RTCC active. The 2.5-3.6 V operating range suits 2xAA or Li-coin cells directly. The 72 MHz core wakes briefly to sample sensors, transmit over USB or UART, and return to sleep, drawing microamp average current. The 32 KB SRAM buffers sensor frames; the 128 KB Flash holds the MPLAB X firmware plus a USB bootloader for field updates.
Recommended
Industrial Control Panel
The industrial temperature range (-40 C to +85 C), USB for diagnostics, and 17 GPIO with Peripheral Pin Select make the PIC32MX254F128BT-I/MM well suited for industrial control panels, HMI keypads, and small PLC I/O modules. The hardware PMP interface can drive character LCDs or small parallel TFTs directly. Three analog comparators support over-current/voltage protection loops. The exposed-pad QFN-S package provides robust thermal performance for enclosed industrial cabinets.
Recommended
Medical Point-of-Care Monitor
The PIC32MX254F128BT-I/MM's 10-bit ADC at 1 Msps with up to 13 analog inputs supports multi-channel physiological signal acquisition (pulse oximetry, temperature, ECG lead-off detection). The 83 DMIPS performance handles digital filtering and USB data streaming to a host PC without an external DSP. The 28-QFN-S (6x6 mm) package fits compact handheld enclosures. Use the RTCC for time-stamping patient measurements and the CTMU for capacitive coupling detection in ECG cables.
Recommended
Home Appliance with USB Diagnostics
Coffee machines, washing machines, and HVAC controllers increasingly use USB ports for service diagnostics and firmware updates. The PIC32MX254F128BT-I/MM integrates USB FS plus all the control peripherals (PWM, ADC, comparators, RTCC) needed for appliance control in a single chip. The 128 KB Flash supports USB MSD bootloader plus full application code. The exposed pad QFN-S package handles the thermal load in enclosed appliance environments.
Recommended
USB Audio / MIDI Device
The PIC32MX254F128BT-I/MM's I2S module combined with USB Full-Speed enables USB Audio Class 1.0 or USB MIDI device implementations. The 72 MHz core handles S/PDIF-to-USB bridging at 48 kHz with low latency. Microchip's MLA USB Audio stack provides reference firmware. The 32 KB SRAM is sufficient for short audio buffers; consider PIC32MX274 variants for multi-channel audio with more RAM. The exposed pad QFN-S package is ideal for compact desktop audio interfaces.
Recommended
Recommended Products Summary
Engineering reference data for PIC32MX254F128BT-I/MM — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC32MX254F128B-I/MM | PIC32MX154F128BT-I/MM | PIC32MX174F256BT-I/MM | PIC32MX170F256BT-I/MM | PIC32MX250F128BT-I/MM |
|---|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 28-QFN-S (6x6 mm) | 28-QFN-S (6x6 mm) - same | 28-QFN-S (6x6 mm) - same | 28-QFN-S (6x6 mm) - same | 28-QFN-S (6x6 mm) - same | 28-QFN-S (6x6 mm) - same |
| Maximum CPU Clock | 72 MHz | 72 MHz | 50 MHz | 50 MHz | 50 MHz | 50 MHz |
| Flash Memory | 128 KB | 128 KB | 128 KB | 256 KB | 256 KB | 128 KB |
| SRAM | 32 KB | 32 KB | 32 KB | 32 KB | 32 KB | 32 KB |
| USB 2.0 Full-Speed | Yes | Yes | Yes | Yes | Yes | No |
| GPIO Count | 17 | 17 | 17 | 17 | 17 | 17 |
| Operating Voltage | 2.5 V to 3.6 V | 2.5 V to 3.6 V | 2.5 V to 3.6 V | 2.5 V to 3.6 V | 2.5 V to 3.6 V | 2.5 V to 3.6 V |
| Operating Temperature | -40 C to +85 C | -40 C to +85 C | -40 C to +85 C | -40 C to +85 C | -40 C to +85 C | -40 C to +85 C |
Key Differentiators
- Higher CPU clock speed within same 28-QFN footprint (vs PIC32MX154F128BT-I/MM)
- Larger Flash memory at same package (vs PIC32MX250F128BT-I/MM)
- Integrated USB 2.0 Full-Speed transceiver (vs PIC32MX170F256BT-I/MM)
Design Notes
The 28-QFN-S package has an exposed thermal pad (EP) that must be soldered to the PCB ground plane. For designs operating at full 72 MHz with USB active, a 4-layer PCB with the EP connected to a continuous ground pour is recommended. Estimate: at VDD = 3.3 V, CPU running at 72 MHz with all peripherals active, core current is roughly 30 mA, giving junction temperature rise of 15-20 C above ambient on a JEDEC EIA/JESD51 4-layer test board.
USB D+ and D- traces must be routed as a 90 ohm differential pair on the top layer with continuous ground reference underneath. Keep the pair length-matched within 150 mil and avoid vias. Place a 100 nF decoupling capacitor within 2 mm of each VDD pin. The VUSB pin requires a 100 nF bypass to ground; without it the internal USB transceiver will not function reliably. Place the 12 MHz primary oscillator within 5 mm of OSC1/OSC2 with a grounded guard ring.
Do not exceed 3.6 V on any VDD pin; the PIC32MX254 is not 5 V tolerant. Configure unused I/O as outputs (not inputs) to avoid parasitic current draw. When using Peripheral Pin Select (PPS), unlock the IOLOCK bit sequence before configuration and lock again afterward to prevent accidental remapping. The CTMU requires the on-chip current source calibration per datasheet section 38 - skip this and your touch readings will drift with temperature.
The 10-bit ADC at 1 Msps requires a low-impedance source (under 1 kohm) for full accuracy. Add a 100 nF bypass on each analog input pin in use. For ACAP/VCAP filtering, route analog and digital ground planes separately and join them at a single point near the IC's VSS pins. The 12 MHz primary oscillator is sensitive to capacitive loading - use a crystal or resonator with specified load capacitance matching the on-chip load caps (typically 8-15 pF).
Compliance Information
RoHS and REACH compliant per Microchip product page. Industrial temperature grade -40 C to +85 C is NOT AEC-Q100 automotive qualified; for automotive use, consider the PIC32MX254F128BT-V/MM automotive variant. Halogen-free per JEDEC JS709.
