MPR084QR2

MPR084QR2 Features

•1.8 V to 3.6 V operation •41 µA average supply current with 1 s response time •2 µA low Standby Current •Variable low power mode response time (32 ms – 4 s) •Rejects unwanted multi-key detections from EMI events such as PAbursts or user handling •Ongoing pad analysis and detection is not reset by EMI events •Data is buffered in a FIFO for shortest access time •IRQ output advises when FIFO has data •System can set interrupt behavior as immediate after event, orprogram a minimum time between successive interrupts •Current touched pad position is always available on demand forpolling-based systems •Sounder output can be enabled to generate key-click sound when padis touched •Two hardware selectable I2C addresses allowing two devices on asingle I2C bus •Configurable real-time auto calibration •5 mm x 5 mm x 1 mm 16 lead QFN package •-40°C to +85°C operating temperature range

MPR084QR2 Typical Applications

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MPR084QR2 Introduction

Freescale Semiconductor’s MPR084 proximity capacitive touch sensor controller is one of a family of products designed to detectthe state of capacitive touch pads. The MPR084 offers designers a cost-efficient alternative to mechanical keys for control panelapplications.The MPR084 uses an I2C interface to communicate with the host which configures the operation and an interrupt to advise thehost of status changes. The MPR084 includes a piezo sounder drive which provides audible feedback to simulate mechanicalkey clicks. The MPR08X family has several implementations to use in your design including control panels and switchreplacements. The MPR084 controls individual touch pads. Other members of the MPR08X family are well suited for otherapplication interface situations such as individual touch pads or rotary/touch pad combinations.Freescale offers a broad portfolio of proximity sensors for products ranging from appliance control panels to portable electronics.Target markets include consumer, appliance, industrial, medical and computer peripherals.1.1.1Devices in the MPR08X seriesThe MPR08X series of Proximity Capacitive Touch Sensor Controllers allows for a wide range of applications andimplementations. Each of the products in Table 1 perform a different application specific task and are optimized for this specificfunctionality.1.1.2

MPR084QR2 Introduction

Freescale Semiconductor’s MPR084 proximity capacitive touch sensor controller is one of a family of products designed to detectthe state of capacitive touch pads. The MPR084 offers designers a cost-efficient alternative to mechanical keys for control panelapplications.The MPR084 uses an I2C interface to communicate with the host which configures the operation and an interrupt to advise thehost of status changes. The MPR084 includes a piezo sounder drive which provides audible feedback to simulate mechanicalkey clicks. The MPR08X family has several implementations to use in your design including control panels and switchreplacements. The MPR084 controls individual touch pads. Other members of the MPR08X family are well suited for otherapplication interface situations such as individual touch pads or rotary/touch pad combinations.Freescale offers a broad portfolio of proximity sensors for products ranging from appliance control panels to portable electronics.Target markets include consumer, appliance, industrial, medical and computer peripherals.1.1.1Devices in the MPR08X seriesThe MPR08X series of Proximity Capacitive Touch Sensor Controllers allows for a wide range of applications andimplementations. Each of the products in Table 1 perform a different application specific task and are optimized for this specificfunctionality.1.1.2Internal Block DiagramThe MPR084 consists of primary functional blocks; Interrupt Controller, I2C Serial Interface, Sounder Controller, Configurationand Status registers, Touch Pad Decoder, Magnitude Comparator and Recalibrator, EMI Burst/Noise Rejection Filter,Capacitance Measurement Analog Front End. Each of these blocks will be described in detail in their respective sections.Figure 2. Functional Block DiagramTable 1. MPR08X Family OverviewProductBusSounderRotary/SliderTouch Pad ArrayMPR083I2CYes8-pads—MPR084I2CYes—8 keysCONFIGURATION AND STATUS REGISTERSMAGNITUDE COMPARATOR AND RECALIBRATOREMI BURST/NOISE REJECT FILTERCAPACITANCE MEASUREMENT A.F.E.888PADENABLEDIRQSDASCLI2CSERIALINTERFACEINTERRUPTCONTROLLERMASKSSETRATEATTNAD0SOUNDERSOUNDERDRIVERCONTROLLERCLEARTOUCHEDPADIDENTIFYDECODERPADCURRENT88 TOUCH PADS