The EM6420 from EM Microelectronics is a true low power Touch Sensor Interface IC able to scan sequentially up to 16 capacitive sensors. The device parameters (number of used sensors, sensors scan frequency, sensors sensitivity level, IRQ condition) are configurable either from a host microcontroller through a communication port or through configuration inputs.
Recognised touch inputs will be signaled with an active edge at the IRQ pad and data are ready to be read through the communication port by the host MCU. Conditions for the IRQ to get active are configurable : at the end of every scan, at the end of a scan if at least one sensor is active or at the end of a scan if the sensors state has changed.
The EM6420 can also detect the most active sensor in applications where sensors are tightly spaced. It compares relative levels among sensors and selects the sensor with the largest signal strength.
To increase the number of sensors >16, use several EM6420 in parallel. The supply voltage range is selectable by pin configuration from 1.2 V to 2.0 V or from 2.2 V to 3.6 V.
- Up to 16 analogue sensor inputs
- User selectable communication interfaces : 4-wire SPI, I2C, 4-bit parallel interface and 8-bit direct output
- User-selectable active edge IRQ output signal
- Active high enable input
- Mobile and cordless phones
- PDA, keyboards
- White goods
- Lighting - Sliders for dimming