PIC32MX250F128B-I/SP - 40MHz 32-bit MCU 128KB Flash 28-SPDIP
MPN: PIC32MX250F128B-I/SP ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $6.73 | $6.73 |
| 10 | $6.05 | $60.50 |
| 100 | $5.37 | $537.00 |
| 500 | $4.81 | $2,405.00 |
| 1,000 | $4.31 | $4,310.00 |
PIC32MX250F128B-I/SP Overview
An MCU (microcontroller unit) is a single-chip computer that combines a CPU core, non-volatile program storage (Flash), working memory (SRAM), and a rich set of on-chip peripherals such as timers, communication interfaces, ADCs, and I/O controllers. PIC32MX250 devices sit in Microchip's mid-range 32-bit PIC32MX family, sitting architecturally between 8-bit PIC16/PIC18 devices and higher-end Cortex-M-class parts. Their role in the broader hierarchy is: microcontroller -> embedded processor -> semiconductor IC.
Key features include two I2S/SPI modules for audio codec and serial communication, Peripheral Pin Select (PPS) for flexible signal routing, a Parallel Master Port (PMP) for graphics interfaces, mTouch capacitive touch support, 1 ns high-resolution time measurement, and on-chip temperature sensing. The device is also equipped with an USB OTG full-speed controller.
The PIC32MX250F128B-I/SP architecture pairs the MIPS M4K core with a multi-channel DMA engine, a 10-bit 1 Msps ADC, five 16-bit timers (plus up to two 32-bit timers), and an input-capture/PWM module. This combination enables real-time deterministic control with minimal CPU overhead, while PPS allows remapping of digital peripherals to almost any I/O pin to ease PCB layout.
Typical applications include industrial control (HMI panels, sensor hubs), USB device peripherals (HID, CDC, audio-USB), consumer audio with I2S codec interfaces, low-cost graphics with PMP-driven LCDs, and capacitive-touch user interfaces (keyboards, control surfaces, white goods).
When designing with this part, pay attention to the 2.3 V to 3.6 V supply range, place a decoupling capacitor on Vcap, and use Microchip's MPLAB X IDE with Harmony framework for firmware development. JTAG/ICSP programming via PICkit or ICD supports in-circuit debugging.
This page synthesizes distributor pricing, drop-in alternative listings, application examples, and design considerations that supplement, rather than duplicate, the Microchip datasheet.
Drop-in alternatives for PIC32MX250F128B-I/SP — 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/SP (same form factor and footprint) — differing in Package, Operating Temperature, Timers, ADC, Core.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC32MX250F128B-50I/SP
✅ Drop-In📋 Reference alternative (not in catalog)
PIC32MX150F128B-I/SP
✅ Drop-In✓ In Stock
$3.56 / Unit
View Datasheet →PIC32MX170F256B-I/SP
✅ Drop-In📋 Reference alternative (not in catalog)
PIC32MX130F064B-I/64B
✅ Drop-In📋 Reference alternative (not in catalog)
PIC32MX250F128B-I/SP Maximum Ratings & Electrical Characteristics
| Core | MIPS32 M4K |
| Core Size | 32-Bit |
| Core Speed | 40 MHz (50 MHz / 83 DMIPS performance) |
| Program Memory (Flash) | 128 KB (128K x 8) |
| RAM | 32 KB |
| Operating Voltage | 2.3 V to 3.6 V |
| I/O Pins | 21 (on 28-SPDIP) |
| Package | 28-SPDIP (0.300", 7.62 mm) |
| Mounting Type | Through-Hole |
| Operating Temperature | -40 °C to +85 °C (Industrial) |
| Connectivity | I2C, IrDA, LIN, PMP, SPI, UART/USART, USB OTG |
| Peripherals | Brown-out Detect/Reset, DMA, I2S, POR, PWM, WDT |
| ADC | 10-bit, 1 Msps |
| Timers | Five 16-bit + up to two 32-bit |
| DMA Channels | Available (multi-channel DMA controller) |
| Data Converters | 10-bit ADC |
| Program Memory Type | Flash |
| Oscillator Type | Internal + PLL |
| PPS (Peripheral Pin Select) | Yes |
| Parallel Master Port (PMP) | Yes |
| USB | USB OTG Full-Speed |
| mTouch Capacitive Touch | Supported |
| On-chip Temperature Sensor | Yes |
| RoHS Status | Compliant |
PIC32MX250F128B-I/SP Pin Configuration
| Pin 1 | MCLR — Master Clear (reset) input, active low |
| Pin 2 | RA0 — I/O port A bit 0 (PPS-capable) |
| Pin 3 | RA1 — I/O port A bit 1 (PPS-capable) |
| Pin 4 | RA2 — I/O port A bit 2 (PPS-capable) |
| Pin 5 | RA3 — I/O port A bit 3 (PPS-capable) |
| Pin 6 | RA4 — I/O port A bit 4 (PPS-capable) |
| Pin 7 | RA5 — I/O port A bit 5 (PPS-capable) |
| Pin 8 | VSS — Ground reference |
| Pin 9 | RA6 — I/O port A bit 6 (PPS-capable) |
| Pin 10 | RA7 — I/O port A bit 7 (PPS-capable) |
| Pin 11 | RB0 — I/O port B bit 0 (PPS-capable, PGED1) |
| Pin 12 | RB1 — I/O port B bit 1 (PPS-capable, PGEC1) |
| Pin 13 | RB2 — I/O port B bit 2 (PPS-capable) |
| Pin 14 | RB3 — I/O port B bit 3 (PPS-capable) |
| Pin 15 | RB4 — I/O port B bit 4 (PPS-capable) |
| Pin 16 | RB5 — I/O port B bit 5 (PPS-capable) |
| Pin 17 | RB6 — I/O port B bit 6 (PPS-capable) |
| Pin 18 | RB7 — I/O port B bit 7 (PPS-capable) |
| Pin 19 | VSS — Ground reference |
| Pin 20 | VCAP — Voltage regulator bypass capacitor |
| Pin 21 | RB8 — I/O port B bit 8 (PPS-capable) |
| Pin 22 | RB9 — I/O port B bit 9 (PPS-capable) |
| Pin 23 | RB10 — I/O port B bit 10 (PPS-capable) |
| Pin 24 | RB11 — I/O port B bit 11 (PPS-capable) |
| Pin 25 | RB12 — I/O port B bit 12 (PPS-capable) |
| Pin 26 | RB13 — I/O port B bit 13 (PPS-capable) |
| Pin 27 | AVSS — Analog ground reference |
| Pin 28 | VDD — Positive supply voltage (2.3 V to 3.6 V) |
Typical Applications
PIC32MX250F128B-I/SP is suitable for 6 applications: Industrial Control & HMI Panels, USB Device Peripherals (HID, CDC, Audio), Consumer Audio with I2S Codecs, Capacitive Touch Keypads (mTouch), Low-Cost PMP-Driven Graphic LCDs, Sensor Hub & Data Acquisition Front-Ends.
Industrial Control & HMI Panels
The PIC32MX250F128B-I/SP fits industrial HMI panels because its 32-bit MIPS core delivers deterministic interrupt response at 50 MHz / 83 DMIPS, while 128 KB Flash and 32 KB SRAM accommodate large state machines, menu trees, and protocol converters. The on-chip 10-bit ADC at 1 Msps reads potentiometers, temperature sensors, and 4-20 mA loop inputs directly. Peripheral Pin Select lets the same PCB layout support PWM outputs, UART lines, and encoder inputs routed to nearly any spare pin, which shortens mechanical-to-electrical porting time. Industrial temperature grade (-40 °C to +85 °C) lets the same firmware survive cabinet-mounted enclosures near motors and contactors, while the brown-out reset prevents corruption during brown-outs in 24 V-supplied systems. USB OTG Full-Speed enables field firmware upgrade via standard MSD drag-and-drop, eliminating the need for an external programmer in production.
Recommended
USB Device Peripherals (HID, CDC, Audio)
The PIC32MX250F128B-I/SP integrates a USB OTG Full-Speed controller with on-chip transceiver and dedicated DMA channels, enabling HID keyboards, CDC virtual COM ports, MSD mass-storage devices, and USB audio class 1.0 devices without external PHY chips. The 32 KB SRAM buffers audio packets at full-speed 12 Mbps polling rates without CPU saturation, leaving headroom for protocol state machines. Two I2S/SPI modules drive external audio codecs, while PPS remaps the I2S signals to spare I/O pins to ease PCB layout under USB-B or USB-C connectors. The 128 KB Flash is large enough to embed USB stacks and composite-class descriptors side by side. Industrial temperature rating (-40 °C to +85 °C) suits POS terminals and industrial USB peripherals that operate near power supplies and switching converters.
Recommended
Consumer Audio with I2S Codecs
The PIC32MX250F128B-I/SP drives external 24-bit I2S audio codecs directly through its two I2S/SPI modules at sample rates up to 192 kHz. Its 50 MHz / 83 DMIPS MIPS M4K core executes DSP-style volume control, EQ, and mixing in real time without audible artifacts. The 32 KB SRAM serves as an audio buffer for USB-streamed or SD-card-sourced playback, while PPS routes BCLK, LRCLK, and DATA to pins that keep them away from switching supply traces to minimize jitter. Compared with 8-bit PIC18 alternatives, the PIC32MX250 offers 32-bit precision in software gain and filter calculations, raising THD+N headroom for compact audio products. mTouch support enables capacitive-button volume control on the same PCB, eliminating mechanical switches and improving moisture resistance.
Recommended
Capacitive Touch Keypads (mTouch)
The PIC32MX250F128B-I/SP supports Microchip's mTouch capacitive touch library directly through its CTMU (Charge Time Measurement Unit) peripheral, with 1 ns time-resolution that detects sub-pF capacitance changes from finger proximity. The 21 available I/O pins on the 28-SPDIP package support up to 21 touch electrodes including sliders and wheels without external scan ICs. The 50 MHz MIPS M4K core runs mTouch scanning plus the application stack (USB HID keyboard, BLE bridge, or LCD UI) in parallel without noticeable scan latency. Industrial temperature rating lets the same firmware operate in kitchen appliances, automotive interiors, and outdoor access panels. mTouch's proximity sensing also enables wake-on-touch for battery applications, dropping quiescent current to microamp levels between touches.
Recommended
Low-Cost PMP-Driven Graphic LCDs
The PIC32MX250F128B-I/SP integrates a Parallel Master Port (PMP) that interfaces directly to character and graphic LCDs in 8-bit parallel mode, including the common ST7565R, ILI9340, and NT7605 controller chips. The PMP bus supports up to 25 MHz read/write cycles with the 50 MHz core, refreshing QVGA displays without DMA saturation. The 32 KB SRAM stores a full screen buffer at lower resolutions, while 128 KB Flash holds font tables and menu assets. Industrial temperature grade (-40 °C to +85 °C) makes the part suited for vending-machine user interfaces, instrumentation front panels, and HVAC control screens. PPS remaps the 8-bit data bus plus control signals to nearly any I/O pin, simplifying PCB routing around mechanical connectors.
Recommended
Sensor Hub & Data Acquisition Front-Ends
The PIC32MX250F128B-I/SP serves as a multi-sensor front-end that aggregates I2C, SPI, and UART sensors, performs on-board signal conditioning, and forwards processed data over USB CDC or CAN. The 10-bit 1 Msps ADC samples analog signals alongside digital sensors, while the multi-channel DMA engine transfers ADC results into RAM without CPU intervention. The 50 MHz MIPS core runs sensor-fusion math, leaving headroom for protocol stacks. 32 KB SRAM buffers burst sensor data, and 128 KB Flash stores calibration tables. PPS lets engineers re-route UART or SPI pins between PCB revisions without re-spinning firmware, accelerating design iterations. Industrial temperature grade suits outdoor sensor pods, environmental monitors, and motor-control feedback boards that operate near hot drivers.
Recommended
Recommended Products Summary
Engineering reference data for PIC32MX250F128B-I/SP — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC32MX250F128B-50I/SP | PIC32MX150F128B-I/SP | PIC32MX170F256B-I/SP | PIC32MX130F064B-I/64B |
|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 28-SPDIP (0.300") | 28-SPDIP (0.300") - same | 28-SPDIP (0.300") - same | 28-SPDIP (0.300") - same | 28-SPDIP (0.300") - same |
| Core Speed | 40 MHz (50 MHz / 83 DMIPS) | 50 MHz / 83 DMIPS | 40 MHz / 50 DMIPS | 50 MHz / 83 DMIPS | 40 MHz / 50 DMIPS |
| Flash Memory | 128 KB | 128 KB | 128 KB | 256 KB | 64 KB |
| RAM | 32 KB | 32 KB | 32 KB | 50 KB | 16 KB |
| USB | USB OTG Full-Speed | USB OTG Full-Speed | None | USB OTG Full-Speed | None |
| 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 |
| Operating Temperature | -40 °C to +85 °C (Industrial) | -40 °C to +85 °C | -40 °C to +85 °C | -40 °C to +85 °C | -40 °C to +85 °C |
Key Differentiators
- Integrated USB OTG Full-Speed with on-chip transceiver (vs PIC32MX150F128B-I/SP)
- 256 KB Flash / 50 KB RAM upgrade path available in same footprint (vs PIC32MX170F256B-I/SP)
- Half-cost memory variant for cost-sensitive designs (vs PIC32MX130F064B-I/SP)
Design Notes
Place a 10 µF ceramic decoupling capacitor (X5R/X7R) close to each VDD/AVDD pair and a 1 µF capacitor at Vcap (pin 7). The internal voltage regulator requires Vcap to be stable for proper operation. According to the Microchip PIC32MX1xx/2xx family reference manual, insufficient Vcap capacitance causes erratic behavior and POR failures during power-up. Brown-out reset (BOR) is enabled by default at 2.3 V to prevent Flash corruption on slow-rising supplies.
Route the ICSP/ICD lines (PGEC1/PGED1 on RB1/RB0) directly to the programming header with short traces and no series resistors. Per Microchip PICkit 3/4 documentation, series resistors on PGEC/PGED degrade debug clock integrity. Keep USB D+/D- traces matched in length (within 150 mil) and away from switching converters; place a 0.1 µF decoupling capacitor at the VUSB pin when USB is used. Use a ground flood under the MCU and stitch vias around high-speed signal exits.
Do not forget to configure PPS (Peripheral Pin Select) before using remapped digital peripherals. PPS unlock sequence uses the OSCCON register and must be followed by the PPS register write - skipping it silently disables the peripheral. Always enable the JTAG port lock (CFG<3> = 1) when JTAG is not used to free RA0/RA1/RA4/RA5 for I/O. Watch the configuration bits: wrong PLL configuration on a 40 MHz target prevents the part from running at all and looks like a dead board.
Use a 27 ohm series resistor on USB D+/D- close to the MCU when the trace length to the connector exceeds 50 mm, per USB 2.0 Full-Speed signal-integrity guidelines. Place the USBLC6-2SC6 ESD protection array within 10 mm of the connector, with the protected-side stub to the MCU kept under 30 mm. Decouple the MCU VUSB pin with 0.1 µF and 4.7 µF in parallel to suppress 480 MHz harmonics on the supply rail.
Compliance Information
RoHS compliant per Microchip product page. Not AEC-Q100 qualified - choose PIC32MX170F256B-I/SP automotive variants for automotive applications. Industrial temperature grade (-40 °C to +85 °C) suitable for non-automotive industrial applications.
