NXP Semiconductors KITMPR03XEVM

Overview

KITMPR03XEVM from NXP Semiconductors (formerly Freescale) is an evaluation kit for the MPR03X capacitive touch sensor controller IC, designed to accelerate development of low-power, two- or three-electrode touch interfaces. It supports I²C communication at up to 400 kbit/s, operates from 1.71 V to 2.75 V, delivers 6 µA supply current with 32 ms response time, and enables rapid prototyping of touch pads in compact 2 mm × 2 mm µDFN packages.

For engineers reviewing the KITMPR03XEVM datasheet, KITMPR03XEVM pinout, KITMPR03XEVM application, or KITMPR03XEVM equivalent, this page provides verified hardware configuration details, supported electrode topologies (2-pad with IRQ or 3-pad without IRQ), register-level control guidance, power optimization trade-offs, and real-world implementation constraints including REXT resistor tolerance (±1%), bypass capacitor requirements (10 µF), and open-drain IRQ pull-up (4.7 kΩ).

Technical Context

The KITMPR03XEVM implements the MPR03X IC in Run1 or Run2 operational modes, supporting either dual-electrode sensing with active-low open-drain interrupt output or triple-electrode sensing with IRQ/ELE2 repurposed as a third input. Its analog front-end includes a 10-bit ADC, three-stage digital filtering (sample, average, debounce), and self-calibrating baseline tracking per electrode.

Hardware design centers on precise external component selection: a 75 kΩ ±1% resistor on REXT sets charge current, while VDD–VSS bypass (10 µF) and IRQ pull-up (4.7 kΩ) are mandatory. The board exposes all eight pins of the 8-lead µDFN package-including SCL, SDA, VDD, VSS, REXT, ELE0, ELE1, and IRQ/ELE2-for direct connection to host microcontrollers and custom electrode layouts.

Key Specifications

Availability

KITMPR03XEVM is available at Aetrix Electronics and suitable for PC peripherals, mobile phone UIs, remote controls, and lighting control systems requiring stable component supply, rapid proof-of-concept validation, and production-ready touch interface characterization.

Supply support for KITMPR03XEVM includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

NXP Semiconductors acquired Freescale in 2015 and maintains legacy product support, documentation, and design resources for the MPR03X family under its broad mixed-signal and human interface portfolio.

The MPR03X product line was engineered specifically for ultra-low-power capacitive touch sensing in space-constrained consumer and portable electronics, emphasizing minimal external components, autonomous baseline calibration, and interrupt-driven host interaction.

FAQ

What is the primary function of the KITMPR03XEVM evaluation kit?

The KITMPR03XEVM evaluation kit is a hardware platform designed to demonstrate and validate the MPR03X capacitive touch sensor controller IC. It enables engineers to configure, test, and characterize touch performance-including electrode count (2 or 3), interrupt behavior, threshold tuning, and power consumption-without developing custom PCBs. The kit includes all necessary passive components and exposes all MPR03X pins for direct interfacing with host controllers.

Does the KITMPR03XEVM support both MPR031 and MPR032 variants?

Yes, the KITMPR03XEVM supports both MPR031 (I²C address 0x4A) and MPR032 (I²C address 0x4B) variants, as confirmed by Freescale's official documentation and schematic compatibility. The board does not hardcode the I²C address; users select the target device via jumper or firmware configuration, enabling side-by-side comparison and multi-device system testing.

What external components are required to operate the KITMPR03XEVM?

The KITMPR03XEVM requires three external components for basic operation: a 75 kΩ ±1% resistor connected from REXT to VSS, a 10 µF bypass capacitor between VDD and VSS, and a 4.7 kΩ pull-up resistor on the IRQ line (when used as interrupt output). These values are specified in Freescale's MPR03X datasheet Section 2.2 and are critical for stable capacitance measurement and noise immunity.

How does the IRQ/ELE2 pin behave in different configurations on the KITMPR03XEVM?

On the KITMPR03XEVM, the IRQ/ELE2 pin functions as an active-low open-drain interrupt output when only two electrodes (ELE0 and ELE1) are enabled - automatically configured in Run1 mode. When three electrodes are enabled, the same pin becomes ELE2 input, disabling interrupt capability. This multiplexing is controlled solely by the EleEn field in the Electrode Configuration Register (0x44), not by hardware jumpers.

Can the KITMPR03XEVM be used to evaluate touch response time and power consumption trade-offs?

Yes, the KITMPR03XEVM allows direct evaluation of response time versus power trade-offs through register configuration. For example, adjusting the Sample Interval (Filter Configuration Register 0x43) and Debounce Count alters response latency (down to 32 ms) and supply current (as low as 6 µA). Real-time current measurement is supported via test points, and timing behavior can be verified using the Touch Status Register (0x00) and IRQ assertion timing.