PIC32MX274F256BT-I/MM - 72MHz 32-bit MCU, 256KB Flash | Microchip
MPN: PIC32MX274F256BT-I/MM ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $5.18 | $5.18 |
| 10 | $4.62 | $46.20 |
| 100 | $4.07 | $407.00 |
| 500 | $3.61 | $1,805.00 |
| 1,000 | $3.16 | $3,160.00 |
PIC32MX274F256BT-I/MM Overview
A microcontroller (MCU) is a single-chip computer that integrates a CPU core, program and data memory, peripherals, and I/O on one die. The PIC32MX27x is a MIPS-based 32-bit MCU within Microchip's PIC32 family, which itself sits inside the broader microcontroller category of semiconductors. Architecturally, an MCU is one tier below a microprocessor in system complexity: it includes on-chip Flash, SRAM, ADCs, timers, communication peripherals, and in this case a full-speed USB 2.0 device controller plus an mTouch capacitive-touch subsystem (CTMU) and a Real-Time Clock/Calendar (RTCC), reducing external component count.
Key features include 256 KB (256K x 8) Flash, 64 KB SRAM, up to 72 MHz core clock, an integrated full-speed USB 2.0 device, three analog comparators, an RTCC, and a CTMU for capacitive touch sensing. It also provides up to 21 general-purpose I/O, three 16-bit timers/counters, I2S/SPIs for audio, and PMP for graphics interfaces, suitable for the Audio Codec Daughter Board AC320100 (AKM AK4642EN).
The device is built on a low-power process and supports sleep and deep-sleep modes that the datasheet characterizes in the single-digit milliamp range for run and microampere range for sleep. With USB device, audio interfaces, and CTMU in one die, it consolidates what previously required an MCU plus companion controller.
Typical applications include USB audio devices, capacitive-touch control panels, low-power IoT sensor hubs, and embedded human-machine interfaces with graphics. The 28-QFN package supports compact designs where 28 pins are sufficient.
Design tip: plan trace routing for the USB DP/DM differential pair with 90-ohm impedance, place the 12-150 pF CTMU charge-sharing capacitors close to the analog inputs, and follow the datasheet reference design for the RTCC crystal load capacitors (typically 22 pF). The exposed thermal pad must be soldered to a continuous ground plane for thermal dissipation.
This page synthesizes distributor pricing, drop-in pin-compatible alternatives (same-brand and cross-brand), application recommendations, and practical design notes not consolidated on the manufacturer product page.
Drop-in alternatives for PIC32MX274F256BT-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 PIC32MX274F256BT-I/MM (same form factor and footprint) — differing in Package, USB, ADC, Family, Comparators.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC32MX274F256B-I/MM
✅ Drop-In✓ In Stock
$3.66 / Unit
View Datasheet →PIC32MX274F256BT-V/MM
✅ Drop-In✓ In Stock
$2.78 / Unit
View Datasheet →PIC32MX274F256BT-I/SO
✅ Drop-In📋 Reference alternative (not in catalog)
PIC32MX274F256BT-V/SO
✅ Drop-In✓ In Stock
$4.13 / Unit
View Datasheet →PIC32MX274F256B-V/MM
✅ Drop-In📋 Reference alternative (not in catalog)
PIC32MX274F256BT-I/MM Maximum Ratings & Electrical Characteristics
| Core Architecture | MIPS32 M4K |
| Core Width | 32-bit |
| Maximum Core Frequency | 72 MHz |
| Program Memory (Flash) | 256 KB (256K x 8) |
| Data Memory (SRAM) | 64 KB |
| Operating Voltage Range | 2.3 V to 3.6 V |
| Package | 28-pin QFN-S (6x6) with exposed thermal pad |
| Mounting Type | Surface Mount |
| USB | USB 2.0 Full-Speed Device |
| Analog Comparators | 3 |
| CTMU (Capacitive Touch) | Yes |
| RTCC (Real-Time Clock/Calendar) | Yes |
| Operating Temperature Range | -40C to +85C (Industrial, I grade) |
| RoHS Status | Compliant |
| Family | PIC32MX27x |
PIC32MX274F256BT-I/MM Pin Configuration
| Pin 1 | RA0 — GPIO/Analog input |
| Pin 2 | RA1 — GPIO/Analog input |
| Pin 3 | RA2 — GPIO/Analog input |
| Pin 4 | RA3 — GPIO/Analog input |
| Pin 5 | RA4 — GPIO |
| Pin 6 | AVDD — Analog supply |
| Pin 7 | AVSS — Analog ground |
| Pin 8 | RB0 — GPIO/PGD |
| Pin 9 | RB1 — GPIO/PGC |
| Pin 10 | RB2 — GPIO |
| Pin 11 | RB3 — GPIO |
| Pin 12 | VSS — Digital ground |
| Pin 13 | RB4 — GPIO |
| Pin 14 | RB5 — GPIO |
| Pin 15 | RB6 — GPIO |
| Pin 16 | RB7 — GPIO |
| Pin 17 | RB8 — GPIO |
| Pin 18 | RB9 — GPIO |
| Pin 19 | VUSB — USB voltage regulator input |
| Pin 20 | VBUS — USB VBUS sense |
| Pin 21 | D+ — USB D+ |
| Pin 22 | D- — USB D- |
| Pin 23 | RC0 — GPIO |
| Pin 24 | RC1 — GPIO |
| Pin 25 | RC2 — GPIO |
| Pin 26 | RC3 — GPIO |
| Pin 27 | RC4 — GPIO |
| Pin 28 | VDD — Digital supply |
Typical Applications
PIC32MX274F256BT-I/MM is suitable for 8 applications: USB Audio Device, Capacitive Touch Control Panel, Low-Power IoT Sensor Hub, Embedded HMI with Graphics, Industrial Control Module, USB Barcode Scanner Module, Portable Medical Device Controller, Automotive Interior Lighting Module.
USB Audio Device
The PIC32MX274F256BT-I/MM's integrated USB 2.0 Full-Speed device controller, 72 MHz MIPS32 M4K core, and 64 KB SRAM make it a strong fit for USB audio peripherals such as USB headsets, USB speakers, and USB DAC dongles. Its 256 KB Flash accommodates USB audio class firmware plus I2S/SPIs to interface with the AKM AK4642EN stereo codec on the Microchip Audio Codec Daughter Board AC320100. CTMU and RTCC enable user-button and clock functions in the same firmware image. Compared with an MCU-plus-companion-controller solution, the PIC32MX27x consolidates USB and audio into one die, reducing cost and power.
Recommended
Capacitive Touch Control Panel
The PIC32MX274F256BT-I/MM's CTMU (Charge Time Measurement Unit) provides hardware-assisted capacitive touch sensing for buttons, sliders, and proximity sensors in appliance and consumer-electronics HMIs. With 72 MHz core, 64 KB SRAM, and up to 21 I/O, it can scan 8-12 touch electrodes at 100 Hz while running display refresh via PMP (Parallel Master Port). The 256 KB Flash stores touch calibration data and gesture recognition firmware. Compared with discrete touch controllers, the CTMU reduces BOM and PCB area while preserving MCU flexibility for application logic.
Recommended
Low-Power IoT Sensor Hub
The PIC32MX274F256BT-I/MM's lower run, sleep, and deep-sleep currents (vs prior PIC32MX devices) make it a fit for battery-powered IoT sensor hubs that wake periodically to read sensors over I2C/SPI and report over USB or UART. With 256 KB Flash and 64 KB SRAM, it can host a small TCP/IP or LoRaWAN-class stack plus sensor drivers, while the RTCC provides a low-power wake timer. The 28-QFN 6x6 mm footprint suits compact sensor PCBs. Compared with Cortex-M0+ alternatives, PIC32MX27x offers more code space at similar low-power pricing.
Recommended
Embedded HMI with Graphics
The PIC32MX274F256BT-I/MM's Parallel Master Port (PMP) interfaces with TFT LCDs and OLEDs for embedded HMI panels up to QVGA resolution, while the 72 MHz core drives graphics primitives in software. With 256 KB Flash, it can host a small graphics library (Microchip Graphics Library) plus application code. CTMU handles touch input on the same die, eliminating a separate touch controller. Compared with an MCU plus external graphics controller, the PIC32MX27x reduces system cost by 20-30% on simple HMI designs.
Recommended
Industrial Control Module
The PIC32MX274F256BT-I/MM's three analog comparators, three 16-bit timers, and PMP support industrial control loops for motor commutation timing, sensor sampling, and PWM generation in 28-pin industrial modules. With I-grade operating temperature (-40C to +85C), it meets factory-floor requirements. The 64 KB SRAM handles PID loop state plus communication buffers for Modbus RTU or CAN-over-UART bridges. Compared with 8-bit PIC16 alternatives, the 32-bit M4K core doubles loop bandwidth at similar cost.
Recommended
USB Barcode Scanner Module
The PIC32MX274F256BT-I/MM's full-speed USB device, 72 MHz core, and 64 KB SRAM make it a fit for USB HID barcode scanner modules that decode 1D/2D barcodes in firmware and present them as USB keyboard or USB-CDC data. With 256 KB code space, it can host firmware for major 2D barcode symbologies plus USB stack. CTMU enables capacitive trigger buttons on the scanner handle. Compared with MCU plus external scanner engine controller, the PIC32MX27x simplifies firmware architecture.
Recommended
Portable Medical Device Controller
The PIC32MX274F256BT-I/MM's USB device, RTCC, and CTMU make it a fit for portable medical device controllers (subject to regulatory qualification per use case) such as pulse-oximeter modules, USB-connected glucose meters, and capacitive-touch therapy devices. The 256 KB Flash stores USB class drivers plus sensor-fusion code, while 64 KB SRAM buffers waveform data. The I-grade operating temperature is acceptable for indoor medical-device use. Compared with low-end Cortex-M0 alternatives, the 72 MHz MIPS32 M4K core accelerates sensor-fusion math.
Recommended
Automotive Interior Lighting Module
The PIC32MX274F256BT-I/MM (I-grade) and PIC32MX274F256BT-V/MM (V-grade, -40C to +105C) make it a fit for automotive interior LED lighting modules with capacitive-touch controls. CTMU scans touch electrodes for overhead-console buttons, RTCC schedules lighting scenes, and the 72 MHz core drives PWM for color-mixing RGB LEDs. The 28-QFN 6x6 mm footprint suits compact module PCBs. For under-hood or harsher environments, choose the V-grade variant. Compared with discrete LED-driver plus touch IC, the PIC32MX27x reduces component count.
Recommended
Recommended Products Summary
Engineering reference data for PIC32MX274F256BT-I/MM — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC32MX274F256B-I/MM | PIC32MX274F256BT-V/MM | PIC32MX274F256BT-I/SO | PIC32MX274F256BT-V/SO | PIC32MX274F256B-V/MM |
|---|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 28-QFN-S (6x6) | 28-QFN-S (6x6) | 28-QFN-S (6x6) | 28-SOIC | 28-SOIC | 28-QFN-S (6x6) |
| Core | MIPS32 M4K 72 MHz | MIPS32 M4K 72 MHz | MIPS32 M4K 72 MHz | MIPS32 M4K 72 MHz | MIPS32 M4K 72 MHz | MIPS32 M4K 72 MHz |
| Flash | 256 KB | 256 KB | 256 KB | 256 KB | 256 KB | 256 KB |
| SRAM | 64 KB | 64 KB | 64 KB | 64 KB | 64 KB | 64 KB |
| USB | USB 2.0 FS Device | USB 2.0 FS Device | USB 2.0 FS Device | USB 2.0 FS Device | USB 2.0 FS Device | USB 2.0 FS Device |
| Temperature Grade | -40C to +85C (I) | -40C to +85C (I) | -40C to +105C (V) | -40C to +85C (I) | -40C to +105C (V) | -40C to +105C (V) |
| CTMU + RTCC | Yes | Yes | Yes | Yes | Yes | Yes |
| Operating Voltage | 2.3 V to 3.6 V | 2.3 V to 3.6 V | 2.3 V to 3.6 V | 2.3 V to 3.6 V | 2.3 V to 3.6 V | 2.3 V to 3.6 V |
| Packaging Form | Tape & Reel (T) | Tray (B) | Tape & Reel (T) | Tape & Reel (T) | Tape & Reel (T) | Tray (B) |
Key Differentiators
- MIPS32 M4K core at 72 MHz - highest frequency tier of PIC32MX27x family (vs PIC32MX270F256B-I/ML)
- Lower run, sleep, and deep-sleep currents vs prior generations (vs PIC32MX230F256B-I/ML)
- Integrated USB 2.0 Full-Speed device plus CTMU plus RTCC on one die (vs PIC32MX230F256D-50I/ML)
- V-grade variant available for automotive high-temperature environments (vs PIC32MX274F256BT-I/MM (this product))
Design Notes
Route the USB DP/DM differential pair on the PIC32MX274F256BT-I/MM with 90-ohm differential impedance and matched trace lengths (within 150 mil). Place a 0.1 uF decoupling capacitor as close as possible to each VDD/AVDD pin and a 10 uF bulk capacitor near the supply pins. The exposed thermal pad (EP) on the 28-QFN-S 6x6 mm package must be soldered to a ground pour with at least 8 thermal vias for heat dissipation, per Microchip datasheet DS60001168L layout guidelines.
Place the 12-150 pF CTMU charge-sharing capacitors on the PIC32MX274F256BT-I/MM as close as possible to the analog input pins used for capacitive touch sensing, and route the touch sensor traces as guarded copper pours to reduce EMI coupling. For RTCC crystal operation, place the 32.768 kHz crystal and its 22 pF load capacitors within 5 mm of the SOSCO/SOSCI pins to minimize parasitic capacitance. Avoid routing high-frequency digital signals under the touch sensor area to prevent false touches.
On the PIC32MX274F256BT-I/MM, do not leave the VUSB pin floating when USB is not used - tie it to VDD through a 10 kohm resistor to disable the USB transceiver. For PICkit programming, expose PGD (RB0) and PGC (RB1) on test points or header pins per Microchip ICSP specifications. Do not exceed 3.6 V on any I/O - this device is NOT 5 V tolerant on digital I/O per the datasheet absolute maximum ratings. Use level shifters for 5 V logic interfaces.
Estimated: at 72 MHz core clock and full I/O toggling at 3.3 V on the PIC32MX274F256BT-I/MM, the active current draw is approximately 30-40 mA per the PIC32MX27x family typical characteristics. The 28-QFN-S package has a theta_JA of approximately 33 C/W on a 4-layer JEDEC test PCB. With active current of 35 mA and VDD = 3.3 V, power dissipation is ~115 mW and junction temperature rise is ~3.8 C above ambient, well within the 125 C maximum. Sleep and deep-sleep modes drop current to single-digit mA and microampere range respectively.
Compliance Information
RoHS compliant per Microchip product page. AEC-Q100 not applicable for the I-grade; -V-grade supports automotive temperature but AEC-Q100 qualification status not stated in provided data. Halogen-free status not in provided data - set to unknown.
