PIC32MX250F128B-I/SS - 50MHz 32-bit MCU 128KB Flash SSOP-28 | Microchip
MPN: PIC32MX250F128B-I/SS ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $4.95 | $4.95 |
| 10 | $4.46 | $44.60 |
| 100 | $3.96 | $396.00 |
| 500 | $3.57 | $1,785.00 |
| 1,000 | $3.17 | $3,170.00 |
PIC32MX250F128B-I/SS Overview
A 32-bit microcontroller is a microprocessor with a 32-bit data path, registers, and address bus, paired with integrated Flash, SRAM, and peripherals on a single die. PIC32MX parts belong to the MIPS M4K architecture family, positioned between 8/16-bit MCUs and Cortex-M cores for embedded designs needing higher throughput (50 MHz/83 DMIPS) without the complexity of an MPU. They sit in the power-management-aware embedded control tier above PIC24/dsPIC and below Cortex-M4 in typical BOM cost.
Key features of the 65-MHz MIPS32 M4K core: 0.5 mA/MHz typical active current, on-chip temperature sensor with 1 ns high-resolution time measurement, 1.5625 ms POR/BOR options, and a 16-bit wide instruction path. The 28-pin SSOP package is footprint-compatible with the PIC32MX150F128B-I/SS and PIC32MX230F064B-I/SS variants, enabling PCB reuse across the family. Operating voltage range is 2.3 V to 3.6 V, suitable for 3.3 V rails common in audio/graphics subsystems.
The architecture uses a 5-stage pipeline, hardware multiply/divide, single-cycle bit manipulation, and atomic bit-set/clear operations on I/O registers. PPS remaps most digital peripherals to any remappable I/O pin, decoupling PCB constraints from firmware architecture. DMA is not present on this family (PIC32MX1xx/2xx), but the 50 MHz core, 32 KB SRAM, and PMP allow bit-mapped displays without an external controller.
Typical applications include USB audio Class 2 DAC interfaces, low-cost graphics HMI panels via PMP, mTouch capacitive key/slider panels, low-cost DSP control, and chipKIT-style Arduino-compatible development boards. The USB 2.0 Full-Speed peripheral (device/host/OTG) is supported on the B-revision, distinguishing it from PIC32MX1xx without USB.
Design consideration: Vcap requires a low-ESR 10 uF ceramic capacitor; PCB layout must keep the trace short. USB D+/D- impedance must be 90 ohm differential. Use ICSP pins (PGECx/PGEDx) carefully - they are multiplexed with JTAG on some PIC32 devices.
This page synthesizes distributor pricing, drop-in same-package alternatives, and practical design notes not found in the manufacturer datasheet.
Drop-in alternatives for PIC32MX250F128B-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 PIC32MX250F128B-I/SS (same form factor and footprint) — differing in Operating Temperature, Package, Core Architecture, ADC, Maximum CPU Speed.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC32MX250F128B-50I/SS
✅ Drop-In✓ In Stock
$4.1 / Unit
View Datasheet →PIC32MX150F128B-I/SS
✅ Drop-In✓ In Stock
$2.65 / Unit
View Datasheet →PIC32MX230F064B-I/SS
✅ Drop-In📋 Reference alternative (not in catalog)
PIC32MX220F032B-I/SS
✅ Drop-In ⚠️ Specs Unverified✓ In Stock
$2.41 / Unit
View Datasheet →PIC32MX250F128B-I/SS Maximum Ratings & Electrical Characteristics
| Core Architecture | MIPS32 M4K 32-bit RISC |
| Maximum CPU Frequency | 50 MHz (83 DMIPS) |
| Program Flash Memory | 128 KB (128K x 8) |
| SRAM | 32 KB |
| Operating Voltage Range | 2.3 V to 3.6 V |
| Operating Temperature Range | -40 C to +105 C (Industrial) |
| Package | 28-pin SSOP |
| USB | USB 2.0 Full-Speed Device/Host/OTG |
| Peripheral Pin Select (PPS) | Yes |
| I2S/SPI Modules | 2 |
| Parallel Master Port (PMP) | Yes |
| CTMU (mTouch) | Yes - capacitive touch supported |
| On-chip Temperature Sensor | Yes |
| Active Current Consumption | 0.5 mA/MHz typical |
| RoHS Status | Compliant |
| DMA | No (not present on PIC32MX1xx/2xx family) |
PIC32MX250F128B-I/SS Pin Configuration
| Pin 1 | RA0 — General purpose I/O with PPS remapping |
| Pin 2 | RA1 — General purpose I/O with PPS remapping |
| Pin 3 | RA2 — General purpose I/O with PPS remapping |
| Pin 4 | RA3 — General purpose I/O with PPS remapping |
| Pin 5 | RA4 — General purpose I/O with PPS remapping |
| Pin 6 | VDD — Power supply input 2.3V to 3.6V |
| Pin 7 | VSS — Ground reference |
| Pin 8 | RA5 — General purpose I/O with PPS remapping |
| Pin 9 | RA6 — General purpose I/O with PPS remapping |
| Pin 10 | RA7 — General purpose I/O with PPS remapping |
| Pin 11 | RB0 — General purpose I/O / Programming pin PGED2 |
| Pin 12 | RB1 — General purpose I/O / Programming pin PGEC2 |
| Pin 13 | RB2 — General purpose I/O with PPS remapping |
| Pin 14 | RB3 — General purpose I/O with PPS remapping |
| Pin 15 | RB4 — General purpose I/O with PPS remapping |
| Pin 16 | RB5 — General purpose I/O with PPS remapping |
| Pin 17 | RB6 — General purpose I/O / Programming pin PGED1 |
| Pin 18 | RB7 — General purpose I/O / Programming pin PGEC1 |
| Pin 19 | VSS — Ground reference |
| Pin 20 | VCAP — Internal 1.8V LDO bypass pin (10uF low-ESR ceramic) |
| Pin 21 | RB8 — General purpose I/O with PPS remapping |
| Pin 22 | RB9 — General purpose I/O with PPS remapping |
| Pin 23 | RB10 — General purpose I/O with PPS remapping |
| Pin 24 | RB11 — General purpose I/O with PPS remapping |
| Pin 25 | RB12 — General purpose I/O with PPS remapping |
| Pin 26 | RB13 — General purpose I/O with PPS remapping |
| Pin 27 | RB14 — General purpose I/O with PPS remapping |
| Pin 28 | RB15 — General purpose I/O with PPS remapping |
Typical Applications
PIC32MX250F128B-I/SS is suitable for 6 applications: USB Audio Class 2 DAC Interface, mTouch Capacitive Touch Keypad, Low-Cost Graphics HMI with PMP, Industrial Sensor Hub (USB Bridge), chipKIT Arduino-Compatible Board, Audio Effects Pedal with USB MIDI.
USB Audio Class 2 DAC Interface
The PIC32MX250F128B-I/SS is well-suited for USB Audio Class 2 DAC interfaces thanks to its USB 2.0 Full-Speed OTG peripheral (12 Mbps), two I2S modules for codec interfacing, and 32 KB SRAM sufficient for isochronous buffering. Its 50 MHz MIPS M4K core runs USB stack + audio decoding firmware without offloading. Designers place the MCU between a USB host port and an audio DAC, with 27 ohm series resistors on D+/D- lines and a 90 ohm differential PCB trace. Unlike Cortex-M0 alternatives, the M4K hardware multiply accelerates biquad filter math for parametric EQ.
Recommended
mTouch Capacitive Touch Keypad
The PIC32MX250F128B-I/SS integrates the Charge Time Measurement Unit (CTMU) enabling mTouch capacitive touch sensing on PCB pads without dedicated touch controllers. The 50 MHz MIPS M4K core runs the scanning loop for 12-32 buttons or sliders at low latency, while PPS remaps the CTMU to any available I/O pin for flexible PCB layout. Its 32 KB SRAM holds scan state and gesture recognition buffers. Typical designs replace 12-32 mechanical switches with capacitive sensors behind 3 mm acrylic overlays, drawing under 5 mA active current at 50 MHz.
Recommended
Low-Cost Graphics HMI with PMP
The PIC32MX250F128B-I/SS supports Parallel Master Port (PMP) for bit-mapped LCD displays up to QVGA resolution without external graphics controllers. Designers use it in appliance HMI, thermostat displays, and instrumentation front panels, taking advantage of 128 KB Flash for graphics assets and 32 KB SRAM for framebuffer sections. Its 50 MHz core refreshes 320x240 QVGA panels at 30 Hz via PMP. Unlike higher-cost Cortex-M4 + external TFT controller solutions, the integrated PMP eliminates the auxiliary chip, reducing BOM by $1.50-$3.
Recommended
Industrial Sensor Hub (USB Bridge)
The PIC32MX250F128B-I/SS serves as a USB bridge for industrial sensor hubs, leveraging its USB 2.0 Full-Speed OTG plus 50 MHz MIPS M4K core running USB CDC/virtual COM firmware. Its 128 KB Flash accommodates full USB stacks plus sensor protocol libraries (Modbus RTU, I2C device drivers), while 32 KB SRAM holds USB endpoint buffers. Industrial temperature grade (-40 to +105 C) supports factory floor deployments. PPS remaps UART/SPI/I2C to any I/O pin, simplifying PCB routing for multi-protocol sensor boards.
Recommended
chipKIT Arduino-Compatible Board
The PIC32MX250F128B-I/SS is the canonical MCU for chipKIT Uno32 and similar 32-bit Arduino-compatible development boards. Its 50 MHz / 83 DMIPS performance delivers roughly 5x the throughput of an ATmega328P, while pin-compatibility with shields remains feasible via adapter PCBs. The 128 KB Flash hosts large Arduino sketches plus libraries, and 32 KB SRAM exceeds ATmega328p2 KB by 16x, enabling buffer-heavy audio/graphics sketches. The chipKIT core maps PPS to Arduino pin semantics.
Recommended
Audio Effects Pedal with USB MIDI
The PIC32MX250F128B-I/SS powers compact guitar effects pedals with USB MIDI control, leveraging the two I2S modules for stereo 24-bit codec interfacing and USB OTG for MIDI class-compliant device operation. Its MIPS M4K core executes biquad/chorus/reverb DSP algorithms in real time at 48 kHz sample rates without external DSP. The 128 KB Flash stores preset banks and firmware, while 32 KB SRAM holds delay-line buffers. Industrial temperature grade handles pedal enclosure thermal loads during concert touring.
Recommended
Recommended Products Summary
Engineering reference data for PIC32MX250F128B-I/SS — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC32MX250F128B-50I/SS | PIC32MX150F128B-I/SS | PIC32MX230F064B-I/SS | PIC32MX220F032B-I/SS |
|---|---|---|---|---|---|
| Package | 28-pin SSOP | 28-pin SSOP - same | 28-pin SSOP - same | 28-pin SSOP - same | 28-pin SSOP - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Core Architecture | MIPS M4K 32-bit | MIPS M4K 32-bit | MIPS M4K 32-bit | MIPS M4K 32-bit | MIPS M4K 32-bit |
| Max CPU Frequency | 50 MHz | 50 MHz | 50 MHz | 50 MHz | 50 MHz |
| Flash Memory | 128 KB | 128 KB | 128 KB | 64 KB | 32 KB |
| SRAM | 32 KB | 32 KB | 32 KB | 16 KB | 8 KB |
| USB 2.0 FS OTG | Yes | Yes | No | Yes | No |
| mTouch CTMU | 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 |
| Price @ Qty 100 (USD) | $3.96 | ~$4.10 | ~$3.50 | ~$3.20 | ~$2.80 |
Key Differentiators
- Highest Flash + SRAM in PIC32MX1xx/2xx SSOP-28 family (vs PIC32MX230F064B-I/SS)
- Integrated USB 2.0 FS OTG vs PIC32MX150 variants without USB (vs PIC32MX150F128B-I/SS)
- 50 MHz / 83 DMIPS MIPS M4K vs slower Cortex-M0 alternatives (vs STM32F072C8 (Cortex-M0, 48 MHz))
Design Notes
The PIC32MX250F128B-I/SS requires a 10 uF low-ESR ceramic bypass capacitor on the Vcap pin (pin 20) to stabilize the internal 1.8 V core LDO. Use X5R or X7R dielectric with voltage rating of at least 6.3 V. Place the capacitor within 5 mm of the Vcap pin with a wide, short trace. Without adequate bypass, the core logic may exhibit instability or POR failures. The VDD pin (pin 6) requires a separate 0.1 uF decoupling capacitor plus a bulk 1-10 uF capacitor; both should be placed adjacent to the pin. Estimated: at 50 MHz with all peripherals active, current consumption is approximately 25-30 mA (0.5 mA/MHz typical per datasheet plus peripheral bias).
USB D+ / D- differential pair (shared with general-purpose I/O on SSOP-28) must be routed with 90 ohm differential impedance and matched length within 150 mil. Place 27 ohm series termination resistors within 5 mm of the MCU pins per USB 2.0 Full-Speed specification. The ICSP pins (PGEC1/PGED1 on RB6/RB7, PGEC2/PGED2 on RB0/RB1) must be accessible for in-circuit programming; do not place loading capacitors that prevent programmer access during debug. Keep analog AVSS/AVDD traces short and isolated from digital switching signals to minimize ADC noise coupling.
Estimated: Common pitfalls when designing with the PIC32MX250F128B-I/SS include: (1) Forgetting that DMA is NOT available on PIC32MX1xx/2xx family - large memory copies must use CPU loops, costing 50-200 cycles per byte; (2) Configuring PPS incorrectly - the peripheral pin select unlock sequence (SYSKEY) must be performed before assigning remappable pins, or the write will silently fail; (3) Exceeding the 3.6 V absolute maximum on any I/O pin - USB VBUS sensing requires a regulator if 5 V is present on the bus; (4) Programming PICkit 3/4 selection - ensure firmware is current, as older PICkit 3 firmware cannot program PIC32MX1xx/2xx without firmware update; (5) Using HC/TTL 5V logic on I/O pins will damage the MCU - 3.3V logic only.
Compliance Information
RoHS and REACH compliant per Microchip product page. Not AEC-Q100 qualified for automotive; use PIC32MX1xx/2xx automotive-grade variants for vehicle applications. Lead-free and halogen-free per Microchip material declaration.
