PIC32MX120F032BT-I/SS - 40MHz 32KB Flash 32-bit MCU | Microchip
MPN: PIC32MX120F032BT-I/SS ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $3.42 | $3.42 |
| 10 | $3.07 | $30.70 |
| 100 | $2.74 | $274.00 |
| 500 | $2.46 | $1,230.00 |
| 1,000 | $2.18 | $2,180.00 |
PIC32MX120F032BT-I/SS Overview
A 32-bit microcontroller (MCU) is a microprocessor that integrates CPU core, memory, and peripherals on a single die. The PIC32MX family uses the MIPS M4K core, which sits in the broader taxonomy of 32-bit RISC microcontrollers -> microcontrollers -> microcontrollers and processors -> semiconductors. Compared with 8-bit and 16-bit MCUs, the 32-bit class delivers higher computational throughput, larger addressable memory, and richer peripherals, enabling single-chip implementations of USB, graphics, audio, and connectivity stacks. The 28-pin SSOP package places this device in the small-outline surface-mount family (SSOP -> SOIC family -> surface-mount -> SMD).
Key specifications include 40 MHz maximum CPU frequency, 32 KB Flash program memory, 8 KB SRAM, 21 GPIO, four hardware DMA channels, and less than 0.5 mA/MHz active current consumption. Integrated peripherals include two UART modules, two I2C modules, two I2S/SPI modules, an Analog-to-Digital Converter (ADC), five 16-bit timers, and a Real-Time Clock and Calendar (RTCC). Programmable Peripheral Pin Select remapping allows flexible pin assignment of most digital peripherals.
The PIC32MX120F032BT-I/SS belongs to the PIC32MX1XX/2XX family, sharing a common peripherals set, registers, and toolchain across 28/36/44-pin variants. The Microchip MPLAB X IDE and the MPLAB XC32 C compiler support this device, and the PIC32 family shares code compatibility across packages and pin counts. Pin-compatible migration paths exist across PIC32MX1XX/2XX 28-pin SSOP parts with different Flash/RAM densities, simplifying BOM selection when memory requirements change.
Typical applications include low-cost USB audio devices, capacitive touch user interfaces, graphics displays using PMP, industrial control panels, sensor hubs, and consumer electronics that need 32-bit performance at 8/16-bit price points. The CTMU peripheral supports mTouch capacitive buttons, sliders, and proximity sensing for human-interface designs.
Designers should note that the SSOP package dissipates approximately 0.5 mA/MHz, so total active power scales linearly with CPU clock. Decoupling capacitors of 100 nF plus 4.7 uF should be placed within 5 mm of the VDD/VSS pairs, and the PPS feature must be configured before peripherals become active on their default pins. Use the SSOP variant rather than SOIC when PCB height is constrained and when the 28-SSOP footprint is already laid out.
This page synthesizes distributor pricing, drop-in alternatives, and practical design notes not found in the manufacturer datasheet alone, and cross-references Microchip PIC32MX1XX/2XX family devices that share the 28-SSOP footprint.
Drop-in alternatives for PIC32MX120F032BT-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 PIC32MX120F032BT-I/SS (same form factor and footprint) — differing in Package, DMA Channels, ADC, Operating Temperature Range, Parallel Master Port (PMP).
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
No drop-in alternatives available for this product.
Request AlternativesPIC32MX120F032BT-I/SS Maximum Ratings & Electrical Characteristics
| Core Architecture | MIPS32 M4K |
| Data Bus Width | 32-bit |
| Maximum CPU Frequency | 40 MHz |
| Program Memory (Flash) | 32 KB (32K x 8) |
| SRAM | 8 KB |
| Supply Voltage Range | 2.3 V to 3.6 V |
| Operating Temperature Range | -40C to +105C |
| GPIO Count | 21 |
| Package | 28-pin SSOP |
| Mounting Type | Surface Mount |
| DMA Channels | 4 |
| Active Current Consumption | < 0.5 mA/MHz |
| UART Modules | 2 |
| I2C Modules | 2 |
| I2S / SPI Modules | 2 |
| Parallel Master Port (PMP) | Yes (graphics interface) |
| Peripheral Pin Select (PPS) | Yes |
| CTMU (mTouch Capacitive Touch) | Yes |
| RoHS Status | Compliant |
PIC32MX120F032BT-I/SS Pin Configuration
| Pin 1 | SDA2/RG3 — I2C2 data or digital I/O pin 3 |
| Pin 2 | SCL2/RG2 — I2C2 clock or digital I/O pin 2 |
| Pin 3 | RA0 — Digital I/O pin 0, analog input |
| Pin 4 | RA1 — Digital I/O pin 1, analog input |
| Pin 5 | RA2 — Digital I/O pin 2, analog input, CTMU |
| Pin 6 | RA3 — Digital I/O pin 3, analog input, CTMU |
| Pin 7 | RA4 — Digital I/O pin 4, CTMU |
| Pin 8 | VSS — Ground reference |
| Pin 9 | RA5 — Digital I/O pin 5, CTMU |
| Pin 10 | RA6 — Digital I/O pin 6, oscillator output |
| Pin 11 | RA7 — Digital I/O pin 7, oscillator input |
| Pin 12 | RB0 — Digital I/O pin 8, programming |
| Pin 13 | RB1 — Digital I/O pin 9, analog input |
| Pin 14 | RB2 — Digital I/O pin 10, analog input |
| Pin 15 | RB3 — Digital I/O pin 11, analog input |
| Pin 16 | VSS — Ground reference (secondary) |
| Pin 17 | RB4 — Digital I/O pin 12, SDA1/I2C1 |
| Pin 18 | RB5 — Digital I/O pin 13, SCL1/I2C1 |
| Pin 19 | RB6 — Digital I/O pin 14, ICDCLK |
| Pin 20 | RB7 — Digital I/O pin 15, ICDDAT |
| Pin 21 | VUSB — USB voltage supply |
| Pin 22 | VBUS — USB bus voltage sense |
| Pin 23 | RB8 — Digital I/O pin 16, USB D- |
| Pin 24 | RB9 — Digital I/O pin 17, USB D+ |
| Pin 25 | VSS — Ground reference (USB) |
| Pin 26 | RC0 — Digital I/O pin 18, analog input |
| Pin 27 | RC1 — Digital I/O pin 19, analog input |
| Pin 28 | VDD — Positive supply voltage |
Typical Applications
PIC32MX120F032BT-I/SS is suitable for 6 applications: Capacitive Touch HMI Panel, Low-Cost USB Audio Device, Graphics Display Driver via PMP, Industrial Sensor Hub, Consumer Appliance Controller, IoT Edge Node Prototype.
Capacitive Touch HMI Panel
The PIC32MX120F032BT-I/SS is well suited to capacitive touch human-machine interface panels thanks to its integrated Charge Time Measurement Unit (CTMU), which supports up to 32 touch channels via the Microchip mTouch software library. With 32 KB Flash and 8 KB SRAM, the device can store a full touch gesture recognition firmware plus GUI bitmaps in external SPI flash. The 40 MHz MIPS M4K core executes scan cycles for 16 buttons in well under 1 ms, while the Peripheral Pin Select (PPS) feature lets designers route touch channels to any spare GPIO. Power consumption is under 20 mA active, making it practical for battery-powered remote controls or wall-mount touch panels in industrial control equipment.
Recommended
Low-Cost USB Audio Device
The PIC32MX120F032BT-I/SS targets low-cost USB audio peripherals such as USB speakers, headsets, and DAC dongles. The integrated USB 2.0 full-speed peripheral with on-chip transceiver, paired with two I2S/SPI modules for codec interfacing, allows direct connection to common audio codecs without an external PHY. The 40 MHz MIPS M4K core runs sample-rate conversion and basic audio processing, while 8 KB SRAM buffers USB isochronous packets. According to the Microchip PIC32MX1XX/2XX datasheet DS60001168L, separate PLLs for CPU and USB clocks allow the CPU to operate at 40 MHz while the USB module runs at 48 MHz, eliminating audio jitter from PLL resynchronization.
Recommended
Graphics Display Driver via PMP
The PIC32MX120F032BT-I/SS integrates a Parallel Master Port (PMP) capable of driving small TFT LCD panels up to 8-bit parallel in master mode, enabling low-cost graphical user interfaces. With 32 KB Flash, the device stores fonts, menus, and basic animation frames. The 40 MHz core refreshes a 128x64 pixel monochrome display at 60 Hz without DMA, while four DMA channels handle offloaded sprite blits for richer UIs. PPS allows remapping the PMP data lines to avoid conflict with touch CTMU pins. Industrial temperature range (-40C to +105C) supports outdoor or factory-floor display applications such as HVAC controllers and appliance front panels.
Recommended
Industrial Sensor Hub
The PIC32MX120F032BT-I/SS serves as a sensor aggregation node in industrial automation systems, fanning in temperature, pressure, and flow data via I2C and SPI, then forwarding aggregated readings over UART or USB. Two I2C modules support dual-sensor buses, while two UARTs enable Modbus RTU on RS-485 transceivers. The 32-bit MIPS M4K core executes floating-point math at 40 MHz, sufficient for simple calibration routines. Less than 0.5 mA/MHz active current keeps thermal dissipation low, and the -40C to +105C range meets industrial environmental specs. The CTMU can also read resistive temperature detectors (RTDs) without external ADCs, reducing BOM cost in dense sensor arrays.
Recommended
Consumer Appliance Controller
The PIC32MX120F032BT-I/SS fits mid-range consumer appliances - washing machines, microwave ovens, and coffee makers - where the 32-bit core handles UI state machines, motor control loops, and sensor monitoring on a single chip. Five 16-bit timers drive brushless DC (BLDC) motor commutation via PWM, while the ADC samples thermistors and current shunts. The 32 KB Flash stores the appliance firmware and configurable user settings, and the 8 KB SRAM buffers log data. The Peripheral Pin Select feature minimizes PCB traces by remapping peripheral signals to alternate pins, and the 28-SSOP package is a low-cost surface-mount option for high-volume consumer production. RoHS compliance meets global environmental directives.
Recommended
IoT Edge Node Prototype
The PIC32MX120F032BT-I/SS provides a low-cost 32-bit platform for prototyping IoT edge nodes with Wi-Fi or Bluetooth co-processors attached via UART or SPI. The MIPS M4K core runs application logic, JSON parsing, and TLS handshake offload coordination, while two UARTs handle AT-command links to wireless modules. With 32 KB Flash and 8 KB SRAM, the device manages TCP/IP stacks via external Wi-Fi controller firmware. The CTMU can read analog sensors such as soil moisture or gas-sensor resistance. PIC32 family migration to higher-density parts (PIC32MX150F128B, PIC32MX2XX) preserves firmware investment as IoT products scale. Microchip MPLAB X IDE and MPLAB Code Configurator accelerate prototype-to-production transitions.
Recommended
Recommended Products Summary
Engineering reference data for PIC32MX120F032BT-I/SS — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | PIC32MX120F032BT-I/SO |
|---|---|---|
| Brand | Microchip Technology | Microchip Technology |
| Package | 28-SSOP | 28-SOIC (different footprint - PCB redesign required) |
| Core Architecture | MIPS32 M4K 32-bit | MIPS32 M4K 32-bit (same) |
| Maximum CPU Frequency | 40 MHz | 40 MHz |
| Flash Memory | 32 KB | 32 KB |
| SRAM | 8 KB | 8 KB |
| Supply Voltage | 2.3 V to 3.6 V | 2.3 V to 3.6 V |
| GPIO Count | 21 | 21 |
| Packaging Format | Tape & Reel | Tape & Reel |
Key Differentiators
- Compact 28-SSOP package with full PIC32MX1XX peripheral set (vs PIC32MX120F032BT-I/SO)
- Tape and reel packaging optimized for SMT assembly (vs PIC32MX120F032B-I/SO (tube pack))
- Integrated CTMU capacitive touch peripheral (vs PIC32MX110F016B-I/SS (no CTMU upgrade in this family tier))
Design Notes
Decouple VDD with a 100 nF ceramic capacitor placed within 5 mm of each VDD/VSS pair, plus a bulk 4.7 uF to 10 uF tantalum or ceramic capacitor on the main VDD rail. The PIC32MX120F032BT-I/SS consumes less than 0.5 mA/MHz active current, so at 40 MHz full-speed CPU operation active current is approximately 20 mA typical. Place bulk decoupling at the IC end of the supply trace and a ferrite bead if the rail feeds other noisy digital loads. The VUSB pin (USB) requires a separate 100 nF bypass capacitor.
Route the 8 MHz external crystal traces (RA6/RA7) symmetrically with short lengths (under 5 mm) and shield them from digital switching lines. The Parallel Master Port (PMP) data lines (RE0-RE7 on larger pin-count variants) and the USB D+/D- differential pair (RB9/RB8) should each be routed as controlled-impedance groups. Use a continuous ground plane under the SSOP-28 footprint to provide thermal sinking and controlled return paths.
Place the SSOP-28 footprint on a single copper pour connected to VDD to spread heat dissipation across the package. Keep clear of high-current switching traces that could inject noise into the analog VDD rail. The Peripheral Pin Select (PPS) feature allows most digital peripherals to be remapped to alternate pins, so lay out for the most convenient PCB routing first, then configure PPS in firmware. Reserve RB6/RB7 for ICD (In-Circuit Debugger) programming access.
Estimated: at 40 MHz full CPU operation with active peripherals, total active current approximates 20 mA. The CTMU peripheral requires careful calibration of the current source trim bits to achieve accurate capacitive touch readings; consult Microchip AN1250 for proper CTMU configuration. The USB peripheral requires the on-chip 48 MHz PLL to be configured before VBUS is applied. Do not omit the 100 nF decoupling on VUSB or USB enumeration will fail intermittently. The PIC32MX120F032BT-I/SS is NOT a drop-in replacement for PIC32MX1XX/2XX parts in different packages - SOIC and SSOP land patterns differ.
Compliance Information
RoHS and REACH compliant per Microchip product page. Lead-free reflow profile per JEDEC J-STD-020. Not AEC-Q100 qualified - select PIC32MX110F016BT-V/SS or other -V suffix parts for automotive-grade designs.
