PIC32MX270F256BT-I/SS - 256KB Flash 32-bit MCU | Microchip
MPN: PIC32MX270F256BT-I/SS ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $6.5 | $6.50 |
| 10 | $5.78 | $57.80 |
| 100 | $5.04 | $504.00 |
| 500 | $4.42 | $2,210.00 |
| 1,000 | $3.89 | $3,890.00 |
PIC32MX270F256BT-I/SS Overview
A microcontroller (MCU) is a single-chip computer that integrates a CPU core, program memory (Flash), working memory (SRAM), and peripheral interfaces (UART, SPI, ADC, timers) into one package. PIC32MX MCUs occupy the 32-bit performance tier of Microchip's PIC32 family — above the 8-bit PIC16/PIC18 devices and below the high-end PIC32MZ — and target applications where designers need MIPS-class arithmetic and ample memory without migrating to Cortex-M silicon.
The PIC32MX270 series is distinguished from the pinout-similar PIC32MX170 by the addition of an integrated USB 2.0 Full-Speed controller with on-chip transceiver. It also features Peripheral Pin Select (PPS), which remaps most digital peripherals to multiple I/O pins, simplifying PCB routing and supporting pin-compatible migration to higher-density packages. Hardware DMA (up to 4 channels) offloads memory-to-peripheral transfers without CPU intervention.
Architecturally, the device uses a 5-stage MIPS32 M4K pipeline with single-cycle atomic bit-set/-clear instructions and a Harvard bus topology separating instruction and data paths to Flash. Separate PLLs drive the CPU and the 48 MHz USB clock, enabling system design without external USB crystal. mTouch capacitive-touch support, CTMU for time measurement, and on-chip temperature sensing round out the analog/mixed-signal peripherals.
Typical applications include USB HID/CDC devices, capacitive touch user panels, low-cost HMI controllers, USB-to-UART bridges, and embedded audio interfaces using the I²S codec link. The 28-SSOP form factor is preferred for hand-solderable designs and cost-sensitive production.
When migrating from a PIC32MX170F256B design to gain USB, the PIC32MX270F256B is the drop-in equivalent — same SSOP-28 footprint, identical peripheral count, and shared USB firmware blob on power-rail sequencing.
This page synthesizes distributor pricing, same-package alternatives from the PIC32 family, and practical design notes not found in the manufacturer datasheet.
Drop-in alternatives for PIC32MX270F256BT-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 PIC32MX270F256BT-I/SS (same form factor and footprint) — differing in Package, ADC, Operating Temperature, USB, Maximum CPU Frequency.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC32MX270F256B-I/SS
✅ Drop-In✓ In Stock
$3.4 / Unit
View Datasheet →PIC32MX170F256B-I/SS
✅ Drop-In✓ In Stock
$2.2 / Unit
View Datasheet →PIC32MX170F256BT-I/SS
✅ Drop-In📋 Reference alternative (not in catalog)
PIC32MX130F256BT-I/SS
✅ Drop-In✓ In Stock
$3.12 / Unit
View Datasheet →PIC32MX250F128B-I/SS
✅ Drop-In✓ In Stock
$3.17 / Unit
View Datasheet →PIC32MX230F256BT-I/SS
✅ Drop-In✓ In Stock
$2.4 / Unit
View Datasheet →PIC32MX270F256BT-I/SS Maximum Ratings & Electrical Characteristics
| Core Architecture | MIPS32 M4K |
| CPU Bit Width | 32-bit |
| Maximum CPU Frequency | 40 MHz (83 DMIPS) |
| Flash Program Memory | 256 KB |
| SRAM | 64 KB |
| Operating Voltage Range | 2.3 V to 3.6 V |
| USB Controller | USB 2.0 Full-Speed with on-chip transceiver |
| ADC | 10-bit, 1 Msps, up to 13 channels |
| UART Modules | 2 |
| SPI / I2S Modules | 2 |
| I2C Modules | 2 |
| Parallel Master Port (PMP) | Yes |
| DMA Channels | 4 (hardware DMA) |
| Peripheral Pin Select (PPS) | Yes |
| Timers | 5 x 16-bit / 2 x 32-bit |
| mTouch Capacitive Touch | Supported via CTMU |
| On-chip Temperature Sensor | Yes |
| Operating Temperature | -40°C to +85°C |
| Package | 28-SSOP (5.30 mm body) |
| Mounting Type | Surface Mount |
| RoHS Status | Compliant |
PIC32MX270F256BT-I/SS Pin Configuration
| Pin 1 | MCLR — Master Clear (reset) input, active-low |
| Pin 2 | RA0 — GPIO / analog input AN0 |
| Pin 3 | RA1 — GPIO / analog input AN1 |
| Pin 4 | PGED1 — ICSP data line (programming/debug) |
| Pin 5 | PGEC1 — ICSP clock line (programming/debug) |
| Pin 6 | RB0 — GPIO / analog input AN2 |
| Pin 7 | RB1 — GPIO / analog input AN3 |
| Pin 8 | RB2 — GPIO / analog input AN4 |
| Pin 9 | RB3 — GPIO / analog input AN5 |
| Pin 10 | RB4 — GPIO / analog input AN6 |
| Pin 11 | RB5 — GPIO / analog input AN7 |
| Pin 12 | RB6 — GPIO / analog input AN8 |
| Pin 13 | RB7 — GPIO / analog input AN9 |
| Pin 14 | RC0 — GPIO |
| Pin 15 | RC1 — GPIO |
| Pin 16 | RC2 — GPIO |
| Pin 17 | RC3 — GPIO |
| Pin 18 | RC4 — GPIO |
| Pin 19 | VSS — Ground reference |
| Pin 20 | VDD — Positive supply (2.3 V to 3.6 V) |
| Pin 21 | RC5 — GPIO |
| Pin 22 | RC6 — GPIO |
| Pin 23 | RC7 — GPIO |
| Pin 24 | RC8 — GPIO |
| Pin 25 | D- — USB D- data line |
| Pin 26 | D+ — USB D+ data line |
| Pin 27 | RA2 — GPIO / analog input AN10 |
| Pin 28 | RA3 — GPIO / analog input AN11 |
Typical Applications
PIC32MX270F256BT-I/SS is suitable for 6 applications: USB HID Peripheral (Keyboard/Mouse/Gamepad), USB CDC Virtual COM Port / USB-UART Bridge, Capacitive Touch Control Panel (mTouch), Low-Cost Audio Interface (USB Audio Class 1.0), Industrial HMI / Parallel Master Port Display, USB Bootloader Host / Field Firmware Update.
USB HID Peripheral (Keyboard/Mouse/Gamepad)
The PIC32MX270F256BT-I/SS is purpose-built for USB Human Interface Device (HID) designs thanks to its integrated USB 2.0 Full-Speed controller with on-chip transceiver, eliminating the need for an external USB PHY or 48 MHz crystal. 256 KB Flash comfortably hosts the Microchip MLA USB HID stack plus application firmware, while 64 KB SRAM supports HID report FIFOs and protocol state. The 40 MHz MIPS M4K core sustains HID polling rates above the 1000 Hz USB Full-Speed ceiling with margin for LED animations and debounce processing. 28-SSOP is ideal for hand-assembled prototypes and small-batch HID peripherals.
Recommended
USB CDC Virtual COM Port / USB-UART Bridge
The integrated USB 2.0 Full-Speed controller makes the PIC32MX270F256BT-I/SS an excellent platform for USB-to-UART bridges that present to the operating system as a CDC ACM serial port. Two hardware UARTs (with PPS routing) can drive two serial channels simultaneously, while 64 KB SRAM buffers sustained serial throughput at 921600 baud. The MLA CDC Basic driver provides cross-platform driver-free enumeration on Windows 10+, Linux, and macOS. Typical applications include industrial configuration ports, factory test fixtures, and embedded debug consoles.
Recommended
Capacitive Touch Control Panel (mTouch)
The PIC32MX270F256BT-I/SS supports mTouch capacitive-touch sensing through the integrated Charge Time Measurement Unit (CTMU) and PPS-routable I/O, enabling up to 13 capacitive touch buttons or a small slider in the 28-SSOP package. The 10-bit ADC with 1 Msps throughput provides fast measurement cycles, while the 40 MHz core executes the touch decoding algorithm in real time. Typical designs include appliance front panels, dimmer switches, and small-format touch user interfaces where mechanical buttons are replaced by capacitive sensors.
Recommended
Low-Cost Audio Interface (USB Audio Class 1.0)
The integrated USB Full-Speed controller supports USB Audio Class 1.0 at 48 kHz / 16-bit, while the two I²S/SPI modules interface directly to low-cost audio codecs. The PIC32MX270F256BT-I/SS is well suited to USB headphone adapters, USB microphones, and small USB speakers that do not need high-bandwidth USB 2.0 High-Speed. 256 KB Flash accommodates the USB Audio Class stack and custom DSP, while the 5-stage MIPS pipeline executes basic audio mixing without a separate DSP chip.
Recommended
Industrial HMI / Parallel Master Port Display
The Parallel Master Port (PMP) on the PIC32MX270F256BT-I/SS directly interfaces to small graphical LCDs and TFT displays, enabling low-cost industrial HMI designs in the 28-SSOP package. The 10-bit ADC supports analog sensor inputs (temperature, pressure, potentiometers), while PPS routing frees any pin to function as a digital I/O or peripheral. Typical designs include small-format operator panels, simple menu-driven thermostats, and instrumentation front panels where a single chip drives display plus user input.
Recommended
USB Bootloader Host / Field Firmware Update
The PIC32MX270F256BT-I/SS is widely deployed as a USB DFU (Device Firmware Upgrade) host or device in field-update-capable products. The integrated USB Full-Speed interface, ample 256 KB Flash for dual-bank bootloader storage, and PPS-routable UARTs for log output simplify secure field-update designs. Microchip's USB DFU bootloader library is pre-validated for this part. This suits industrial sensors, smart appliances, and connected equipment that must accept firmware updates without physical access to programming pins.
Recommended
Recommended Products Summary
Engineering reference data for PIC32MX270F256BT-I/SS — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC32MX270F256B-I/SS | PIC32MX170F256B-I/SS | PIC32MX170F256BT-I/SS | PIC32MX130F256BT-I/SS | PIC32MX250F128B-I/SS |
|---|---|---|---|---|---|---|
| Package | 28-SSOP | 28-SSOP - same | 28-SSOP - same | 28-SSOP - same | 28-SSOP - same | 28-SSOP - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Flash Memory | 256 KB | 256 KB | 256 KB | 256 KB | 256 KB | 128 KB |
| SRAM | 64 KB | 64 KB | 64 KB | 64 KB | 64 KB | 64 KB |
| Maximum Clock | 40 MHz (83 DMIPS) | 40 MHz (83 DMIPS) | 40 MHz (83 DMIPS) | 40 MHz (83 DMIPS) | 40 MHz (83 DMIPS) | 50 MHz (83 DMIPS) |
| USB Controller | USB 2.0 Full-Speed | USB 2.0 Full-Speed | None | None | None | USB 2.0 Full-Speed |
| ADC | 10-bit, 1 Msps | 10-bit, 1 Msps | 10-bit, 1 Msps | 10-bit, 1 Msps | 10-bit, 1 Msps (with 16-bit mode) | 10-bit, 1 Msps |
| Peripheral Pin Select (PPS) | 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 |
Key Differentiators
- Integrated USB 2.0 Full-Speed controller with on-chip transceiver (vs PIC32MX170F256B-I/SS)
- Higher-performance 50 MHz option in same 28-SSOP footprint (vs PIC32MX250F128B-I/SS)
- Same-package alternative with 16-bit ADC mode for precision analog (vs PIC32MX130F256BT-I/SS)
Design Notes
Decouple VDD (pin 20) with a 100 nF X7R capacitor placed within 5 mm of the pin, plus a bulk 4.7 uF to 10 uF tantalum or ceramic capacitor on the same net. The PIC32MX270F256B has separate internal digital and analog supply rails; route AVDD to the same 3.3 V net but isolate with a ferrite bead or small resistor when noise-sensitive analog measurements are at scale. VSS (pin 19) must connect to a low-impedance ground plane with multiple stitching vias for return-current management.
The 28-SSOP package has a 0.65 mm pitch with thermal pad requirements — no center pad is exposed, but keep ground copper continuous for 40 MHz current return. Route the USB D+/D- traces (pins 25/26) as a 90 ohm differential pair with length matching within 150 mil. Avoid routing the USB traces near switching regulators or high-current traces; place a ground pour under the USB traces for return-path integrity.
Place the ICSP pins (PGED1/PGEC1, pins 4/5) on a 0.1-inch header accessible for in-circuit programming and debugging via PICkit 3/4. Place a 10 kohm pull-up on MCLR (pin 1) per the device family reference manual. The 28-SSOP body is 5.30 mm wide — leave at least 0.5 mm clearance on each side of the package for solder mask and paste stencil. Use a 0.5 mm pitch stencil aperture for the SSOP leads.
Do not exceed 3.6 V on VDD or 5 V tolerance on any digital I/O pin — applying 5 V to a 3.3 V I/O pin will damage the part. Always configure the unused I/O pins as outputs (not floating inputs) to avoid shoot-through current. The USB bus-powered configuration requires a 10 uF bulk capacitor on VBUS and ferrite bead filtering; non-USB designs should leave the USB D+/D- pins unconnected. Configure the on-chip LDO properly via the ENVREG pin setting per the datasheet, or the internal 2.5 V core regulator may not start up.
Compliance Information
RoHS compliant per Microchip product page. Industrial temperature grade -40C to +85C (I suffix). Not AEC-Q100 qualified; for automotive applications consider PIC32MK or SAM E70 series.
