PIC32MX270F256BT-I/ML - 32-bit MCU 256KB Flash 40MHz | Microchip
MPN: PIC32MX270F256BT-I/ML ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $5.84 | $5.84 |
| 10 | $5.31 | $53.10 |
| 100 | $4.72 | $472.00 |
| 500 | $4.13 | $2,065.00 |
| 1,000 | $3.66 | $3,660.00 |
PIC32MX270F256BT-I/ML Overview
An MCU (Microcontroller Unit) is a single-chip computer containing a processor core, program and data memory, timers, ADCs, and a range of digital and analog peripherals. PIC32MX microcontrollers sit within Microchip's PIC32 family of MIPS-based 32-bit MCUs, themselves part of the broader PIC microcontroller family that bridges 8-bit PIC16/PIC18 designs to 32-bit ARM Cortex-M class devices. They target cost-sensitive embedded designs where 32-bit performance and USB connectivity are required without migrating to ARM Cortex-M cores.
Key differentiating features of the PIC32MX270F256BT-I/ML include its USB 2.0 full-speed OTG support (rare in this pin-count class), 256KB self-programmable Flash with 64KB SRAM, Peripheral Pin Select (PPS) for flexible remapping of digital peripherals to almost any I/O pin, the Charge Time Measurement Unit (CTMU) for capacitive touch and 1 ns time resolution, and Parallel Master Port (PMP) for graphics or external memory interfaces. The device operates from 2.3V to 3.6V, drawing approximately 0.5 mA/MHz typical active current.
The architecture combines a single-cycle MIPS32 M4K core with 5-stage pipeline, hardware multiplier/divider, dedicated DMA controller with up to 8 channels, and a prefetch cache that mitigates Flash wait-state penalty at 40 MHz. The 256KB Flash supports runtime self-programming under bootloader control, while the 64KB SRAM is large enough for IP stacks (TCP/IP, USB, audio) without external memory. JTAG and two-wire ICSP debug interfaces are available alongside trace support.
Typical applications include USB HID/CDC device peripherals, audio playback with I2S DACs and PWM output, low-cost graphics interfaces via PMP, mTouch capacitive buttons and sliders on consumer appliances, industrial sensor hubs, and low-bandwidth wireless sensor nodes. The CTMU also enables accurate pulse-width and temperature measurement in instrumentation.
Designers should pay attention to decoupling on VDDCORE and VDDPLL pins, the 4-wire or 2-wire ICSP programming interface, and the USB D+/D- trace routing for 90 ohm differential impedance. PPS mapping must be configured before peripheral use, and unused I/O should be set as outputs low or inputs with weak pull-ups to minimize power. The exposed pad (EP) on the ML package must be soldered to the central ground pour for thermal and electrical performance.
This page synthesizes distributor pricing, drop-in alternatives, and practical design notes not found in the manufacturer datasheet alone.
Drop-in alternatives for PIC32MX270F256BT-I/ML — 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 PIC32MX270F256BT-I/ML (same form factor and footprint) — differing in Package, ADC, Operating Temperature, Core Architecture, MSL Level.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC32MX270F256B-I/ML
✅ Drop-In📋 Reference alternative (not in catalog)
PIC32MX270F256BT-50I/ML
✅ Drop-In📋 Reference alternative (not in catalog)
PIC32MX270F256BT-40V/ML
✅ Drop-In📋 Reference alternative (not in catalog)
PIC32MX250F256B-I/ML
✅ Drop-In📋 Reference alternative (not in catalog)
PIC32MX170F256BT-I/ML
✅ Drop-In✓ In Stock
$3.62 / Unit
View Datasheet →PIC32MX230F256D-50I/ML
✅ Drop-In✓ In Stock
$3.96 / Unit
View Datasheet →PIC32MX254F128DT-I/ML
✅ Drop-In✓ In Stock
$2.62 / Unit
View Datasheet →PIC32MX174F256DT-I/ML
✅ Drop-In✓ In Stock
$2.55 / Unit
View Datasheet →PIC32MX270F256BT-I/ML Maximum Ratings & Electrical Characteristics
| Core | MIPS32 M4K 32-bit RISC |
| Maximum CPU Speed | 50 MHz / 83 DMIPS |
| Operating Frequency (this part) | 40 MHz |
| Program Flash | 256 KB (256K x 8) |
| SRAM | 64 KB |
| Supply Voltage (VDD) | 2.3 V to 3.6 V |
| Active Current (typical) | 0.5 mA/MHz |
| Package | 28-QFN (ML) 6x6 mm with exposed pad |
| Pin Count | 28 |
| I/O Pins | 21 |
| ADC | 10-bit, up to 13 channels |
| USB | USB 2.0 Full-Speed Device/Host/OTG |
| Serial Interfaces | 2x I2S, 2x SPI, 2x I2C, 2x UART |
| Timers | 5x 16-bit |
| DMA Channels | Up to 8 |
| PWM Outputs | Yes (from Output Compare / 16-bit timers) |
| Peripheral Pin Select (PPS) | Yes |
| Parallel Master Port (PMP) | Yes |
| Charge Time Measurement Unit (CTMU) | Yes (mTouch, 1 ns time resolution) |
| On-chip Temperature Sensor | Yes |
| Operating Temperature | -40 C to +85 C (Industrial, I grade) |
| Mounting Type | Surface Mount |
| MSL Level | 1 |
| RoHS Status | Compliant |
PIC32MX270F256BT-I/ML Pin Configuration
| Pin 1 | RF0/PGC2 — Digital I/O / ICSP clock (programming/debug) |
| Pin 2 | RF1/PGD2 — Digital I/O / ICSP data (programming/debug) |
| Pin 3 | RB0 — Digital I/O / PGED1 (programming) |
| Pin 4 | RB1 — Digital I/O / PGEC1 (programming) |
| Pin 5 | RB2 — Digital I/O / analog AN4 |
| Pin 6 | RB3 — Digital I/O / analog AN5 |
| Pin 7 | VDD — Positive supply (2.3 V to 3.6 V) |
| Pin 8 | VSS — Ground |
| Pin 9 | RB4 — Digital I/O / analog AN6 |
| Pin 10 | RB5 — Digital I/O / analog AN7 |
| Pin 11 | RB6 — Digital I/O / analog AN8 |
| Pin 12 | RB7 — Digital I/O / analog AN9 |
| Pin 13 | RB8 — Digital I/O / analog AN10 |
| Pin 14 | RB9 — Digital I/O / analog AN11 |
| Pin 15 | RB10 — Digital I/O / analog AN12 |
| Pin 16 | RB11 — Digital I/O / analog AN13 |
| Pin 17 | RB12 — Digital I/O |
| Pin 18 | RB13 — Digital I/O |
| Pin 19 | VBUS — USB VBUS sense input |
| Pin 20 | D- — USB data minus |
| Pin 21 | D+ — USB data plus |
| Pin 22 | RC0 — Digital I/O |
| Pin 23 | RC1 — Digital I/O |
| Pin 24 | RC2 — Digital I/O |
| Pin 25 | RC3 — Digital I/O |
| Pin 26 | RC4 — Digital I/O |
| Pin 27 | RC5 — Digital I/O |
| Pin 28 | EP — Exposed thermal pad - must be soldered to ground |
Typical Applications
PIC32MX270F256BT-I/ML is suitable for 6 applications: USB HID and CDC Peripherals, Audio Playback with I2S DAC, mTouch Capacitive Button Interfaces, Industrial Sensor Hubs, Low-Cost Graphics with PMP, Wireless Sensor Nodes (with External Radio).
USB HID and CDC Peripherals
The PIC32MX270F256BT-I/ML is ideal for USB HID/CDC peripherals because it integrates a USB 2.0 full-speed OTG controller with on-chip transceiver, eliminating the need for external bridge chips like FTDI or CP2102. With 256 KB Flash it easily fits the USB HID class descriptor and Microchip Harmony framework, while 64 KB SRAM accommodates USB endpoint buffers and protocol stacks. Designers route D+/D- as a 90 ohm differential pair, supply 48 MHz to the USB PLL, and call the Harmony USB stack to enumerate as HID or virtual COM port. The 40 MHz MIPS32 M4K core handles enumeration and polling interrupts in less than 5% CPU, leaving headroom for the application task. Compared to a discrete MCU plus FT232 solution, this single-chip approach reduces PCB area by 30-40% and BOM cost by roughly USD 1.50 per node.
Recommended
Audio Playback with I2S DAC
The PIC32MX270F256BT-I/ML fits digital audio playback designs because it integrates two I2S modules that interface directly to external DACs such as the PCM5102A or CS4344, and the DMA controller moves 16-bit/44.1 kHz stereo sample streams without CPU intervention. The 40 MHz MIPS32 M4K core decodes WAV/MP3/FLAC samples with enough MIPS left over for UI and volume control, while the 256 KB Flash stores small audio assets on-chip. Designers place the MCU on a dedicated 3.3 V analog supply rail and connect MCLK/BCLK/LRCK/DIN to the DAC. Compared with PIC32MX170 alternatives, the PIC32MX270 retains the same I2S module count but adds USB streaming capability for a single-chip USB audio DAC. CTMU support enables precision touch-button volume controls with 1 ns resolution.
Recommended
mTouch Capacitive Button Interfaces
The PIC32MX270F256BT-I/ML is well suited for mTouch capacitive touch buttons and sliders because the on-chip Charge Time Measurement Unit (CTMU) measures capacitance with 1 ns resolution using only an external pull-up resistor per electrode. With 256 KB Flash and 64 KB SRAM the MCU can run Microchip's mTouch libraries plus a small graphics UI, while the PPS function lets designers route CTMU channels to any pin for flexible PCB layout. Typical designs achieve 4-12 buttons and 2 sliders using a 4-layer board with proper ground guarding. The 0.5 mA/MHz active current keeps average power consumption below 15 mA even with all peripherals enabled. Compared to discrete touch ICs, the integrated CTMU approach removes a separate chip and consolidates touch handling with the main application code on the PIC32MX270.
Recommended
Industrial Sensor Hubs
The PIC32MX270F256BT-I/ML works as an industrial sensor hub because the 10-bit ADC with up to 1 Msps samples multi-channel analog sensors while I2C/SPI buses read digital temperature, pressure, or accelerometer peripherals. The 256 KB Flash runs a Modbus RTU slave or MQTT-SN client stack, and the 64 KB SRAM buffers data between acquisition cycles and network transmission. The industrial -40C to +85C temperature range suits factory-floor enclosures, and the 2.3-3.6 V supply tolerates 24 V industrial rails when paired with a step-down DC-DC converter. CTMU enables high-precision timing for ultrasonic flow sensors or capacitive proximity detectors. Compared to lower-pin PIC32MX1XX/2XX variants, the 28-QFN B-suffix retains USB for diagnostic interfaces and field firmware updates via bootloader.
Recommended
Low-Cost Graphics with PMP
The PIC32MX270F256BT-I/ML drives low-cost graphics displays via the Parallel Master Port (PMP) because PMP provides 8-bit data, address, and control lines that interface directly to OLED, TFT, or character LCD controllers such as SSD1306 and ILI9341. The 256 KB Flash stores full font tables and small bitmap libraries, while the 40 MHz CPU refreshes a 128x64 OLED comfortably with up to 50% spare MIPS for application logic. PMP timing is configurable for bus speed and setup/hold, and DMA can offload frame-buffer updates. Compared with SPI-only graphics, PMP cuts display refresh time by 3-5x and supports larger panels up to 240x320 QVGA without CPU bottlenecks.
Recommended
Wireless Sensor Nodes (with External Radio)
The PIC32MX270F256BT-I/ML is a good host MCU for low-bandwidth wireless sensor nodes because the 256 KB Flash holds a 6LoWPAN or LoRaWAN application layer plus Microchip's TCP/IP stack, and the 64 KB SRAM buffers queued transmissions. UART/SPI ports connect to external radios such as the RN2483 LoRa module or MRF24XA Wi-Fi transceiver, while the CTMU measures battery voltage and sensor capacitance. Average current under sleep with RTCC active is below 50 uA, suiting battery-powered deployments. The 28-QFN (6x6 mm) leaves room for compact PCB designs, and USB on the same MCU simplifies field firmware updates via the bootloader. Compared with smaller PIC32MX1XX MCUs, the PIC32MX270 adds USB-OTG for tethered setup and debugging without extra components.
Recommended
Recommended Products Summary
Engineering reference data for PIC32MX270F256BT-I/ML — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC32MX270F256B-I/ML | PIC32MX270F256BT-50I/ML | PIC32MX270F256BT-40V/ML | PIC32MX250F256B-I/ML | PIC32MX170F256BT-I/ML |
|---|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 28-QFN (ML) 6x6 mm | 28-QFN (ML) 6x6 mm - same | 28-QFN (ML) 6x6 mm - same | 28-QFN (ML) 6x6 mm - same | 28-QFN (ML) 6x6 mm - same | 28-QFN (ML) 6x6 mm - same |
| Core Architecture | MIPS32 M4K 32-bit | MIPS32 M4K 32-bit - same | MIPS32 M4K 32-bit - same | MIPS32 M4K 32-bit - same | MIPS32 M4K 32-bit - same | |
| Maximum CPU Speed | 40 MHz | 40 MHz | 50 MHz | 40 MHz | 50 MHz | 50 MHz |
| Flash Memory | 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 2.0 OTG | Yes | Yes | Yes | Yes | No | No |
| Operating Temperature | -40C to +85C (I grade) | -40C to +85C | -40C to +85C | -40C to +105C (V grade) | -40C to +85C | -40C to +85C |
| Supply 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 |
Key Differentiators
- Tape-and-reel packaging for SMT production (vs PIC32MX270F256B-I/ML)
- Industrial temperature grade for cost-sensitive applications (vs PIC32MX270F256BT-40V/ML)
- 40 MHz speed grade matches industrial cost target (vs PIC32MX270F256BT-50I/ML)
- Integrated USB 2.0 OTG eliminates bridge ICs (vs PIC32MX170F256BT-I/ML)
Design Notes
The PIC32MX270F256BT-I/ML requires careful power decoupling on each VDD/VSS pair: place a 100 nF ceramic capacitor as close as possible to every VDD pin (7 in this 28-QFN package) plus a shared 4.7 uF bulk capacitor near the regulator. The on-chip voltage regulator produces VDDCORE at 1.8 V; decouple its output with 1 uF + 100 nF to provide a stable core voltage. USB applications must supply 48 MHz to the USB PLL via a 12 MHz crystal multiplied internally; inadequate decoupling on VBUS introduces noise on D+/D- that can fail USB compliance tests.
USB differential pair routing is the single most important PCB layout concern for the PIC32MX270F256BT-I/ML. Route D+ and D- as a 90 ohm differential pair with length matching within 150 mil, keep the pair away from high-frequency clocks or switching regulators, and provide an unbroken ground reference plane beneath the traces. The exposed thermal pad (pin 28 EP) MUST be soldered to a central ground pad with multiple thermal vias to the inner ground plane; failure to solder it reduces thermal performance and can cause intermittent connectivity. Match the 28-QFN (ML) 6x6 mm land pattern to Microchip's recommended PCB footprint, with 0.4 mm pitch pads.
Three common pitfalls when bringing up the PIC32MX270F256BT-I/ML: (1) forgetting to configure Peripheral Pin Select (PPS) before using digital peripherals - PPS mapping must be assigned at startup or the I/O will not respond; (2) not enabling the USB PLL or missing the 12 MHz crystal, which causes USB enumeration to fail silently; (3) failing to solder the central exposed pad, leading to high junction temperatures or unexpected resets during peak load. Also ensure the ICSP clock (PGC2/PGD2, pins 1-2) is not loaded down by external circuitry, as this prevents in-circuit programming and debugging. Use Microchip Harmony or MPLAB Code Configurator to avoid missing required configuration bits.
Estimated: at 40 MHz active mode, the PIC32MX270F256BT-I/ML draws approximately 20 mA typical (0.5 mA/MHz x 40 MHz) from a 3.3 V supply, dissipating roughly 66 mW. In the 28-QFN (ML) 6x6 mm package with the exposed pad soldered to a 4-layer 1 oz copper ground pour, the thermal resistance theta_JA is approximately 35 C/W, yielding a junction temperature rise of only ~2.3 C above ambient. Sleep modes reduce current to single-digit microamps with RTCC active. For battery-powered designs, use deep sleep with RTCC wake-up to achieve multi-year battery life when the CTMU and ADC are idle.
Compliance Information
RoHS3 compliant per Microchip product page. Not AEC-Q100 qualified - choose PIC32MX270F256BT-40V/ML for automotive temperature grade (-40C to +105C).
