STMPE321QTR

Touch Capacitive Sensor Overview

The STMPE321QTR is a 3-channel capacitive touchkey controller manufactured by STMicroelectronics. It operates within a supply voltage range of 1.65 V to 1.95 V and features an I2C interface supporting standard (up to 100 kbps) and fast (up to 400 kbps) modes with 7-bit and 10-bit addressing. The device provides up to 3 GPIOs or capacitive touchkey inputs, offering 40 fF resolution and 128-step capacitance measurement. It includes advanced data filtering, environment tracking calibration, and individually adjustable touch variance settings. The component is housed in a QFN12 package measuring 2.2 x 1.5 mm and is supplied in tape and reel packaging.

Touch Capacitive Sensor Feature Summary

• Supports up to 3 channels configurable as either general-purpose I/O or capacitive touchkey inputs via I2C configuration.
• Integrates advanced data filtering and environment tracking calibration algorithms for reliable touch detection.
• Features adjustable touch variance and environmental variance settings to optimize sensitivity across different conditions.
• Provides an interrupt output pin and supports multiple power states including active, sleep, and hibernate modes.

Touch Capacitive Sensor Applications

• Mobile phones and smartphones
• Portable media players
• Game consoles

Touch Capacitive Sensor Procurement Notes

Verify the specific ordering suffix 'QTR' corresponds to the tape and reel packing format required for automated assembly processes. Confirm that the operating voltage range of 1.65 V to 1.95 V aligns with the target system's power supply rails. Ensure the I2C bus voltage levels are compatible with the host controller, noting the 3.3 V tolerance on the interface pins.

Touch Capacitive Sensor Selection Notes

Select this component when a compact solution for up to three capacitive touch keys is required. The QFN12 package offers a small footprint suitable for space-constrained portable designs. Consider the low power consumption in sleep mode if battery life is a critical design parameter. Verify that the I2C address 0x58 does not conflict with other devices on the bus.

Touch Capacitive Sensor Part Context

The STMPE321 belongs to the STMPE series of peripheral controllers from STMicroelectronics. This series focuses on providing dedicated hardware solutions for human-machine interface functions such as touch sensing and key scanning. The STMPE321 specifically targets applications requiring simple, low-pin-count capacitive touch interfaces without the complexity of full touchscreen controllers.

Touch Capacitive Sensor Replacement Considerations

Public confirmed substitute part numbers are not available in the provided documentation. Evaluate alternative STMPE models or similar capacitive touch controllers based on channel count, package compatibility, and I2C interface requirements.