Proximity Capacitive Touch Sensor Controllers - MPR081 and MPR082 - Freescale

Freescale Semiconductor introduced of two highly sensitive touch pad controllers. The MPR081 and MPR082 proximity capacitive touch sensor controllers are designed to detect touch by measuring capacitance. The MPR081 chip is ideal for rotary interface applications and the MPR082 is well suited for touch pad applications. Touch sensors offer a low-cost alternative to mechanical push buttons for applications such as home/office appliances, access controls,  mobile phones, PC peripherals and remote controls and other consumer electronic products.

Proximity detection provides the latest technology for the user to interact with consumer electronics. Touch sensing is one of the most popular applications because it:

• Enables the elimination of mechanical buttons and sliders
• Provides the ability to automate intuitively through our fingertips
• Gives greater flexibility for product designers
• Enhances reliability by eliminating mechanical wear and tear
• Reduces overall system costs

Replacing mechanical buttons on smart portable electronics enables a larger LCD display and orientation placement options. Additionally, the proximity sensor electrode layouts can be changed easily, depending on the device's portrait or landscape mode.

Freescale’s MPR082 Block Diagram. see below…

Example of Implementations proximity sensors:

• Control panels
• Switch replacements
• Rotary and linear sliders
• Touch pads

The proximity sensors have a common pin-out, which simplifies management of control panels, switch replacements, rotary and linear sliders, and touch pad implementations. Both touch sensor devices use a digital output I2C interface to communicate. The voltage operation range is 1.8 to 3.6V, which is ideal for consumer electronics. The devices have a sound driver that provides audible feedback to simulate mechanical key clicks.

The MPR081 proximity touch sensor controller

The MPR081 proximity sensor is a user interface controller which manages a 16-quadrant rotary touch pad. It uses an I2C interface to communicate with the host which configures the operation and an interrupt to advise the host of status changes. The MPR081 includes a piezo sounder which provides audible feedback to simulate mechanical key clicks.

Freescale’s MPR081 Proximity Capacitive Touch Sensor Controller - Application Block Diagram

Features of  MPR081 proximity sensor:

• Supports a 16-position rotary
• Ongoing pad analysis and detection not reset by EMI events
• Proprietary false touch rejection technology
• IRQ output advises when FIFO has data
• System can set interrupt behavior as immediate after event or program a minimum time between successive interrupts
• Digital output (I2C with custom addressing)
• Sounder drive provides audible feedback to simulate mechanical key clicks
• 1.8 - 3.6 V operation
• 1 μA standby current
• 150 μA average supply current (all touch pads being monitored)
• 16-pin QFN and TSSOP packages
• -40°C to +85°C operating temperature range

The MPR082 proximity touch sensor controller

The MPR082 proximity sensor is a user interface controller which manages 20 touch pads. It uses an I2C interface to communicate with the host, which configures the operation, and an interrupt to advise the host of status changes. The MPR082 includes a piezo sounder which provides audible feedback to simulate mechanical key clicks.

Freescale’s MPR082 Proximity Capacitive Touch Sensor Controller - Application Block Diagram

Features of  MPR082 capacitive proximity sensor

• Controls up to 20 touch pads
• Proprietary false touch rejection technology
• Ongoing pad analysis and detection not reset by EMI events
• IRQ output advises when FIFO has data
• System can set interrupt behavior as immediate after event or program a minimum time between successive interrupts
• Digital output (I2C with custom addressing)
• Sounder drive provides audible feedback to simulate mechanical key clicks
• 1.8 - 3.6 V
• 1 μA standby current
• 150 μA average supply current (all touch pads being monitored)
• 16-pin QFN and TSSOP packages
• -40°C to +85°C operating temperature range

MPR081 and MPR082 proximity touch sensor controllers  are expected to be available in Q4 this year. Price starts at US$1.07 each for 10K qty.

To speed-up implementation of these proximity capacitive touch sensor controllers, Freescale offers the KITMPR081EVM and KITMPR082EVM  evaluation kits.  Price: US$99 each.

More info: Freescale’s proximity capacitive touch sensor controllers