PIC32MX120F032B-50I/SS - 50MHz 32-bit MCU 32KB Flash | Microchip
MPN: PIC32MX120F032B-50I/SS ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $2.75 | $2.75 |
| 10 | $2.48 | $24.80 |
| 100 | $2.2 | $220.00 |
| 500 | $1.96 | $980.00 |
| 1,000 | $1.74 | $1,740.00 |
PIC32MX120F032B-50I/SS Overview
A microcontroller (MCU) is a single-chip computer that integrates a CPU core, non-volatile program memory (Flash), volatile working memory (SRAM), and configurable peripherals onto one die. The PIC32MX1XX/2XX family sits in the hierarchy: microcontroller -> 32-bit MCU -> MIPS M4K architecture -> Microchip PIC32MX series -> entry-level flash-MCU segment. Designed for connected and low-power embedded designs, the PIC32MX120 line is the lowest pin-count / lowest Flash member of the family, targeting cost-sensitive applications that still need 32-bit performance, USB-OTG, or graphics peripherals.
Key features that distinguish this part include Peripheral Pin Select (PPS), which remaps most digital I/O to virtually any I/O pin for flexible PCB routing; a 16-bit Parallel Master Port (PMP) for external memory or graphics; a Charge Time Measurement Unit (CTMU) for mTouch capacitive-touch buttons and sliders; and a 10-bit 1 Msps Analog-to-Digital Converter with up to 13 analog input channels. The PIC32MX120 also integrates a real-time clock-calendar, a watchdog timer, and multiple power-management modes that drop quiescent current into the microamp range for battery-powered designs.
Architecturally, the PIC32MX120 uses a Harvard-style MIPS32 M4K core with a 5-stage pipeline, single-cycle multiply, hardware divide, and tightly-coupled prefetch module to keep Flash accesses from bottlenecking execution. The 50 MHz (-50) speed grade is the higher-performance bin of the family and supports 50 MHz operation across the full industrial temperature range, while the 40 MHz (-40) grade supports 40 MHz only. Industrial-grade silicon (-I) is rated to 105 C ambient.
Typical applications for the PIC32MX120F032B-50I/SS include low-cost consumer devices, mTouch capacitive touch user interfaces, audio playback systems using the I2S codec interface, low-end graphics terminals driven by PMP, USB device peripherals in the 28-pin form factor, and industrial sensor / control nodes. The 32 KB Flash comfortably holds small graphical menus, USB stacks (e.g. Microchip MLA / Harmony Lite), and RTOS workloads.
When designing with this part, plan for an external supervisor or internal POR delay for clean reset behavior, place the 8 MHz-40 MHz crystal within 10 mm of the OSC pins, and follow Microchip's recommendations for decoupling (0.1 uF + 4.7 uF within 5 mm of each VDD/VSS pair). The CTMU requires an external current-setting resistor; PPS mappings must be locked after configuration to avoid glitches during runtime. For migration to higher pin-count members, the PIC32MX130/150/170/270 families share this die with additional Flash and peripherals and are upward-compatible in software.
This page synthesizes distributor pricing, drop-in alternatives in the same 28-SSOP footprint, and practical design notes not found in the manufacturer datasheet.
Drop-in alternatives for PIC32MX120F032B-50I/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 PIC32MX120F032B-50I/SS (same form factor and footprint) — differing in Package, Program Memory (Flash), Core Architecture, ADC, Operating Temperature Range.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
PIC32MX130F032B-50I/SS
✅ Drop-In📋 Reference alternative (not in catalog)
PIC32MX110F016B-I/SS
✅ Drop-In✓ In Stock
$1.84 / Unit
View Datasheet →PIC32MX170F032B-50I/SS
✅ Drop-In📋 Reference alternative (not in catalog)
PIC32MX130F064B-I/SS
✅ Drop-In✓ In Stock
$2.43 / Unit
View Datasheet →PIC32MX150F032B-50I/SS
✅ Drop-In📋 Reference alternative (not in catalog)
PIC32MM0064GPM028-I/SS
✅ Drop-In✓ In Stock
$2.55 / Unit
View Datasheet →PIC32MM0256GPM028T-I/SS
✅ Drop-In✓ In Stock
$2.55 / Unit
View Datasheet →PIC32MX120F032B-50I/SS Maximum Ratings & Electrical Characteristics
| Core Architecture | MIPS32 M4K 32-bit RISC |
| Core Count | Single-core |
| Maximum CPU Frequency | 50 MHz |
| Program Memory (Flash) | 32 KB (32K x 8) |
| Data RAM | 8 KB |
| Operating Voltage Range | 2.3 V to 3.6 V |
| Operating Temperature Range | -40 C to +105 C (Industrial) |
| Active Current | < 0.5 mA/MHz |
| I/O Pins | 21 (multiplexed) |
| Package | 28-pin SSOP |
| Mounting Type | Surface Mount |
| ADC | 10-bit, 1 Msps, up to 13 channels |
| DMA Channels | 4 |
| UART | 2 (with LIN and IrDA support) |
| SPI | 2 (shared with I2S) |
| I2C | 2 |
| Parallel Master Port (PMP) | Yes, 16-bit |
| Peripheral Pin Select (PPS) | Yes |
| CTMU (mTouch) | Yes |
| RoHS Status | Compliant |
PIC32MX120F032B-50I/SS Pin Configuration
| Pin 1 | PGED3/AN0/RPB0/RB0 — Programming data, analog input 0, or GPIO |
| Pin 2 | PGEC3/AN1/RPB1/RB1 — Programming clock, analog input 1, or GPIO |
| Pin 3 | VSS — Ground reference |
| Pin 4 | AN2/C1INC/RPB2/RB2 — Analog input 2, comparator 1 input, or GPIO |
| Pin 5 | AN3/C1IND/RPB3/RB3 — Analog input 3, comparator 1 input, or GPIO |
| Pin 6 | PGEC1/VREF-/CVREF-/AN4/RB4 — Programming clock, VREF-, or analog input 4 |
| Pin 7 | PGED1/VREF+/CVREF+/AN5/RB5 — Programming data, VREF+, or analog input 5 |
| Pin 8 | AN6/RPB6/RB6 — Analog input 6 or GPIO |
| Pin 9 | AN7/RPB7/RB7 — Analog input 7 or GPIO |
| Pin 10 | VSS — Ground reference |
| Pin 11 | VDD — Positive supply (2.3 V to 3.6 V) |
| Pin 12 | OSCI/CLKI/RA3 — External oscillator input or GPIO |
| Pin 13 | OSCO/CLKO/RA2 — External oscillator output or GPIO |
| Pin 14 | TDO/RA1 — Trace data output or GPIO |
| Pin 15 | TCK/RA0 — Trace clock or GPIO |
| Pin 16 | TMS/RPB8/RB8 — Test mode select or GPIO |
| Pin 17 | VBUS/AN8/RPB9/RB9 — USB VBUS detect (PIC32MX220/250 only) or analog input 8 |
| Pin 18 | D-/AN10/RPB11/RB11 — USB D- (on USB variants) or analog input 10 |
| Pin 19 | D+/AN11/RPB10/RB10 — USB D+ (on USB variants) or analog input 11 |
| Pin 20 | VDD — Positive supply (2.3 V to 3.6 V) |
| Pin 21 | VSS — Ground reference |
| Pin 22 | AN12/RPC0/RC0 — Analog input 12 or GPIO |
| Pin 23 | AN13/RPC1/RC1 — Analog input 13 or GPIO |
| Pin 24 | RPC2/SDA1/RC2 — I2C1 SDA or GPIO (PPS-remappable) |
| Pin 25 | RPC3/SCL1/RC3 — I2C1 SCL or GPIO (PPS-remappable) |
| Pin 26 | RPC4/PMA0/RC4 — PMP address 0 or GPIO |
| Pin 27 | RPC5/PMA1/RC5 — PMP address 1 or GPIO |
| Pin 28 | RPC6/PMA2/RC6 — PMP address 2 or GPIO |
Typical Applications
PIC32MX120F032B-50I/SS is suitable for 6 applications: mTouch Capacitive Touch User Interface, Low-Cost Audio Player with I2S Codec, Industrial Sensor Node / Modbus RTU, USB HID / CDC Device Firmware (Migration Variant), Small TFT / Graphics Terminal, Battery-Powered Low-Power Embedded Device.
mTouch Capacitive Touch User Interface
The PIC32MX120F032B-50I/SS fits mTouch capacitive touch interfaces thanks to its on-chip Charge Time Measurement Unit (CTMU), 10-bit ADC, and 50 MHz MIPS core that runs Microchip's touch firmware libraries with low latency. With up to 13 ADC channels, the MCU can scan 12+ touch electrodes at 10 ms update rates while leaving CPU headroom for housekeeping. The CTMU provides a hardware-based charge-time measurement that is robust against humidity and temperature drift, and the 32 KB Flash accommodates Microchip's mTouch reference firmware plus application code. Designers place 1 nF to 10 nF touch pads on PCB, route them to ADC-capable pins, and add a single current-setting resistor for the CTMU. The 28-SSOP footprint also keeps BOM cost low versus larger QFP parts typically used in capacitive touch designs.
Recommended
Low-Cost Audio Player with I2S Codec
The PIC32MX120F032B-50I/SS drives low-cost audio playback through its two I2S/SSP peripherals, which interface directly to codecs such as the Microchip WM8904 family or TI TLV320AIC3x. At 50 MHz, the core can handle 16-bit/44.1 kHz stereo audio decoding from compressed formats (WAV, ADPCM, Ogg Vorbis via the Helix library) with sustained CPU cycles to spare for UI and storage. The 8 KB SRAM is sufficient for small audio buffers, and the 32 KB Flash holds the decoder plus a basic menu UI. The I2S module, together with DMA-driven playback, offloads the CPU and supports sample-accurate timing. The PMP can also drive a small TFT display for cover art. Industrial temperature rating makes it suitable for in-vehicle infotainment prototypes and public-address devices.
Recommended
Industrial Sensor Node / Modbus RTU
The PIC32MX120F032B-50I/SS is well-suited for low-cost industrial sensor nodes using Modbus RTU, thanks to its two UART peripherals (with LIN/IrDA support) and the wide 2.3 V to 3.6 V supply range that operates directly from a 24 V->3.3 V industrial bus. The 50 MHz MIPS core executes Modbus RTU handling, sensor sampling, and digital filtering with substantial headroom. The 10-bit ADC and CTMU handle 4-20 mA loop interfaces, RTD bridges, or capacitive proximity sensors. The -I industrial temperature grade (-40 C to +105 C) supports unheated enclosures, and PPS allows flexible PCB routing for compact sensor modules. Designers pair it with an isolated RS-485 transceiver, a 3.3 V LDO, and a small OLED driven by PMP or SPI to build a full sensor gateway in the 28-SSOP footprint.
Recommended
USB HID / CDC Device Firmware (Migration Variant)
Although the PIC32MX120F032B-50I/SS does not include a USB module, it is frequently designed in alongside the pin-compatible PIC32MX220F032B-50I/SS (same 28-SSOP footprint, with USB-OTG added). The PIC32MX120 variant handles non-USB housekeeping; the 220 variant in the same socket adds USB on demand. This strategy gives product lines a single PCB that supports USB and non-USB SKUs. For pure USB devices, designers typically start with PIC32MX250F128B-50I/SS instead, which integrates USB-OTG with 128 KB Flash. Microchip's MLA USB stack provides HID, CDC, and MSD class drivers, all running comfortably at 50 MHz on this MIPS M4K core.
Recommended
Small TFT / Graphics Terminal
The PIC32MX120F032B-50I/SS drives small TFT displays via its 16-bit Parallel Master Port (PMP), which can directly interface 8-bit and 16-bit parallel LCDs at speeds sufficient for QVGA (320x240) panels. The 50 MHz MIPS core can refresh graphics buffers while handling a small RTOS, USB-OTG, or touch UI. The CTMU is unused in graphics but available if the display has a capacitive overlay. The 28-SSOP footprint pairs well with PMP-driven QVGA panels, and the 8 KB SRAM is enough for small framebuffer-only designs (use partial refresh). For larger screens, the PIC32MX170/270 series upgrade the Flash/RAM while keeping the same 28-pin footprint on the higher-pin-count packages.
Recommended
Battery-Powered Low-Power Embedded Device
The PIC32MX120F032B-50I/SS suits battery-powered designs thanks to its active current under 0.5 mA/MHz at 50 MHz (around 25 mA at full load) and dedicated low-power sleep modes that drop the core into microamp-range quiescent current. Combined with the wide 2.3 V to 3.6 V supply, it can run directly from a single Li-ion (3.0 V to 4.2 V) or two alkaline cells (2.6 V to 3.2 V). The CTMU wakes the MCU on capacitive touch; the RTCC maintains timekeeping during sleep. Designers use the PIC32's low-power modes (Sleep, Deep Sleep with RTCC) to keep idle current in single-digit microamps for battery life in the multi-month range. The 28-SSOP keeps the board compact, and PPS remaps wake sources to any pin to optimize sleep-current routing.
Recommended
Recommended Products Summary
Engineering reference data for PIC32MX120F032B-50I/SS — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC32MX130F032B-50I/SS | PIC32MX110F016B-I/SS | PIC32MX170F032B-50I/SS | PIC32MM0064GPM028-I/SS |
|---|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | 28-SSOP | 28-SSOP (same) | 28-SSOP (same) | 28-SSOP (same) | 28-SSOP (same) |
| Core Architecture | MIPS32 M4K 32-bit | MIPS32 M4K 32-bit | MIPS32 M4K 32-bit | MIPS32 M4K 32-bit | PIC32MM (MIPS M4K-compatible) 32-bit |
| Maximum CPU Frequency | 50 MHz | 50 MHz | 40 MHz (-20%) | 50 MHz | 25 MHz (-50%) |
| Flash Memory | 32 KB | 64 KB (+100%) | 16 KB (-50%) | 256 KB (+700%) | 64 KB (+100%) |
| RAM | 8 KB | 8 KB | 4 KB (-50%) | 64 KB (+700%) | 8 KB |
| Operating Voltage Range | 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 | 2.0 V to 3.6 V |
| Operating Temperature Range | -40 C to +105 C (Industrial) | -40 C to +105 C | -40 C to +105 C | -40 C to +105 C | -40 C to +125 C (extended) |
| USB Module | Not present on this part | Not present | Not present | Not present | Not present |
Key Differentiators
- Upward Flash scaling without PCB change (vs PIC32MX110F016B-I/SS)
- Lower-power peripheral core for energy-conscious designs (vs PIC32MX130F032B-50I/SS)
- Cost-optimized entry into PIC32 family (vs PIC32MX170F032B-50I/SS)
Design Notes
Decoupling: place a 0.1 uF ceramic capacitor within 5 mm of every VDD/VSS pair (pins 3/10/11 and 20/21/22 on the 28-SSOP), and add a single 4.7 uF bulk tantalum or ceramic capacitor near the MCU. The PIC32MX120F032B-50I/SS draws peaks above 25 mA when the MIPS core is active at 50 MHz; without local decoupling the supply sag can trigger POR. A ferrite bead plus 10 uF capacitor pair isolates analog VREF+ (pin 7) from digital noise. Use a star-ground topology with separate analog and digital ground planes that tie together at the VSS pin nearest the MCU.
Crystal placement: keep the 8 MHz to 40 MHz crystal or resonator within 10 mm of the OSCI (pin 12) and OSCO (pin 13) pins, with a continuous ground guard trace on the layer below. Keep high-speed digital traces (PMP, SPI) at least 5 mm away from the oscillator loop. If using the internal RC oscillator instead, leave pins 12/13 floating or as GPIO via PPS and ground the crystal traces. Route the ICSP PGECx/PGEDx pairs (pins 1/2 and 6/7) as a short, parallel pair with a ground shield for reliable in-circuit programming.
Peripheral Pin Select (PPS) lock: PPS mappings must be configured and then LOCKED before runtime to avoid accidental remapping by buggy firmware. PIC32MX120 has limited PPS output options on remappable pins - verify the exact mapping in the family datasheet's I/O chapter. Also avoid using PGEC1/PGED1 (pins 6/7) for JTAG-style debug on production firmware without a debug disable fuse, since this allows in-field firmware read-back. Configure the appropriate configuration bits in your linker script to lock the device against unauthorized readout. The CTMU requires an external current-setting resistor on a designated pin; omitting this resistor yields incorrect capacitance readings.
Compliance Information
RoHS and REACH compliant per Microchip product page; industrial temperature grade -I, not AEC-Q100 qualified for automotive applications. Use Microchip's automotive-grade /VAO or /Q equivalents for AEC-Q100 designs.
