CPT112S-A01-GMR

TouchXpress™ Family CPT112S Data Sheet The CPT112S device, part of the TouchXpress family, is designed to quickly add capacitive touch via an I2C interface by eliminating the firmware complexity and reducing the development time for capacitive sensing applications. Supporting up to 12 capacitive sensor inputs in packages as small as a 3 mm x 3 mm QFN, the CPT112S is a highly-integrated device that interfaces via I2C to the host processor to provide a simple solution for adding capacitive touch. The device also comes with advanced features like moisture immunity, wake-on proximity, and buzzer feedback for an enhanced user experience. No firmware development is needed, and all the capacitive touch sense parameters can be configured using a simple GUI-based configurator. By eliminating the need for complex firmware development, the CPT112S device enables rapid user interface designs with minimal development effort. The CPT112S device is ideal for a wide range of capacitive touch applications including the following: • Medical equipment • Consumer electronics • Lighting control • Home appliances • Instrument / Control panels • White goods Input Features Capacitive Touch Sensing Features KEY FEATURES • No firmware development required • Simple GUI-based configurator • 12 Capacitive Sensor inputs with programmable sensitivity • Configurable multi-button slider • I2C interface to communicate to the host • Lowest power capacitive sense solution • Active — 200 µA • Sleep — 1 µA • Wake on proximity • Superior noise immunity: SNR up to 270:1 • Moisture immunity • Mutually-exclusive touch qualifier • Button touch time-out to avoid false touches • Buzzer output for audible touch feedback Output Features Proximity Wake Input Touch Qualification MutuallyExclusive Touch Qualifier I2C Output I2C Event Buffer Option for a Multi-Button Slider Configuration Profile for each Input Baselining Interrupt Pin Optional Buzzer Output Input Engine with 12 Inputs Low Power State Machine Touch Time-Out Timer Lowest power mode with feature operational: Active Optimized Active Low Power Sleep silabs.com | Smart. Connected. Energy-friendly. This information applies to a product under development. Its characteristics and specifications are subject to change without notice. Preliminary Rev. 0.2 CPT112S Data Sheet Feature List and Ordering Information 1. Feature List and Ordering Information CP T 1 12 S – A 02 – G M R Tape and Reel (Optional) Package Type — QFN20 (M), QSOP24 (U) Temperature Grade — –40 to +85 °C (G) Firmware Revision Hardware Revision Capacitive Sense Features — Slider (S) Number of Capacitive Sense Inputs Interface Type — GPO (0), I2C (1) TouchXpress Family Silicon Labs Xpress Product Line Figure 1.1. CPT112S Part Numbering The CPT112S has the following features: • Capacitive sensing input engine with 12 inputs • Post-sample touch qualification engine • Configuration profile space in non-volatile memory • I2C event buffer with interrupt pin to signal when new touch events have been qualified • Low power state machine to minimize current draw in all use cases • Capacitive proximity sensing input • Buzzer output • Mutually-exclusive touch qualifier • Touch time-out timer Package QFN20 CPT112S-A02-GU Yes -40 to +85 °C QSOP24 silabs.com | Smart. Connected. Energy-friendly. (RoHS Compliant) -40 to +85 °C Pb-free Yes Part Number CPT112S-A02-GM Ordering Temperature Range Table 1.1. Product Selection Guide Preliminary Rev. 0.2 | 1 CPT112S Data Sheet Typical Connection Diagrams 2. Typical Connection Diagrams 2.1 Signal, Analog, and Power connections Figure 2.1 Connection Diagram on page 2 shows a typical connection diagram for the power pins of CPT112S devices. CPT112S Device 1.8-3.6 V (in) 4.7 µF and 0.1 µF bypass capacitors required for the power pins placed as close to the pins as possible. VDD GND 1.8-3.6 V (in) Host Processor EB_SCL EB_SDA EB_INT CS00 Electrode ... CS10 Electrode 1.8-3.6 V (in) Config Data Config Clk / RSTb Figure 2.1. Connection Diagram silabs.com | Smart. Connected. Energy-friendly. Preliminary Rev. 0.2 | 2 CPT112S Data Sheet Typical Connection Diagrams 2.2 Configuration The diagram below shows a typical connection diagram for the configuration connections pins. The ToolStick Base Adapter is available on the evaluation board. CPT112S Device VDD 1k Config Clk Config Data GND ToolStick Figure 2.2. Configuration Connection Diagram silabs.com | Smart. Connected. Energy-friendly. Preliminary Rev. 0.2 | 3 CPT112S Data Sheet Electrical Specifications 3. Electrical Specifications 3.1 Electrical Characteristics All electrical parameters in all tables are specified under the conditions listed in Table 3.1 Recommended Operating Conditions on page 4, unless stated otherwise. 3.1.1 Recommended Operating Conditions Table 3.1. Recommended Operating Conditions Parameter Symbol Operating Supply Voltage on VDD VDD Minimum RAM Data Retention Voltage on VDD1 VRAM Operating Ambient Temperature TA Test Condition Min Typ Max Unit 1.8 2.4 3.6 V Not in Sleep Mode — 1.4 — V Sleep Mode — 0.3 0.5 V –40 — 85 °C Note: 1. All voltages with respect to GND. silabs.com | Smart. Connected. Energy-friendly. Preliminary Rev. 0.2 | 4 CPT112S Data Sheet Electrical Specifications 3.1.2 Power Consumption See 3.4 Typical Performance Curves for power consumption plots. Table 3.2. Power Consumption Parameter Symbol Active Mode Supply Current Min Typ Max Unit IDD — 3.1 — mA Optimized Active Mode Supply Current IDD — 180 — µA Sleep Mode Current1, 2 IDD 3 sensors or fewer — 0.78 — µA 4 sensors — 0.79 — µA 5 sensors — 0.81 — µA 6 sensors — 0.82 — µA 7 sensors — 0.84 — µA 10 sensors — 0.88 — µA 12 sensors — 0.95 — µA Scan period = 10 ms — 154 — µA Scan period = 20 ms — 77 — µA Scan period = 50 ms — 31 — µA Scan period = 75 ms — 21 — µA Scan period = 100 ms — 16 — µA Scan period = 10 ms — 47 — µA Scan period = 20 ms — 23 — µA Scan period = 50 ms — 9 — µA Scan period = 75 ms — 6 — µA Scan period = 100 ms — 5 — µA System Current with Varying Scan Time — Base with One Sensor1 System Current with Varying Scan Time — Each Additional Sensor1 IDD IDD Test Condition Note: 1. Measured with Free Run Mode disabled and sensors set to 4x accumulation, 8x gain. 2. Measured with scan period set to 250 ms. silabs.com | Smart. Connected. Energy-friendly. Preliminary Rev. 0.2 | 5 CPT112S Data Sheet Electrical Specifications 3.1.3 Reset and Supply Monitor Table 3.3. Reset and Supply Monitor Parameter Symbol Test Condition Min Typ Max Unit VDD Supply Monitor Threshold VVDDM Reset Trigger 1.7 1.75 1.8 V VWARN Early Warning 1.8 1.85 1.9 V Power-On Reset (POR) Monitor Threshold VPOR Rising Voltage on VDD — 1.75 — V Falling Voltage on VDD 0.75 1.0 1.3 V VDD Ramp Time tRMP — — 3 ms RST Low Time to Generate Reset tRSTL 15 — — µs Boot Time1 tboot 1 sensor — 25 — ms 2 sensors — 40 — ms 3 sensors — 55 — ms 4 sensors — 70 — ms 5 sensors — 85 — ms 6 sensors — 100 — ms 7 sensors — 115 — ms 8 sensors — 130 — ms 9 sensors — 145 — ms 10 sensors — 160 — ms 11 sensors — 175 — ms 12 sensors — 200 — ms Time to VDD ≥ 1.8 V Note: 1. Boot time is defined as the time from a power-on reset or /RST pin release until the first capacitive sense scan begins. 3.1.4 Configuration Memory Table 3.4. Configuration Memory Parameter Symbol Endurance (Write/Erase Cycles) NWE Test Condition Min Typ Max Units 20 k 100 k — Cycles Note: 1. Data Retention Information is published in the Quarterly Quality and Reliability Report. silabs.com | Smart. Connected. Energy-friendly. Preliminary Rev. 0.2 | 6 CPT112S Data Sheet Electrical Specifications 3.1.5 Capacitive Sense Table 3.5. Capacitive Sense Parameter Symbol Test Condition Scan Time Per Sensor1 tSCAN Signal to Noise Ratio1, 2 Conversion Time Total Processing Time3 Maximum External Capacitive Load SNR tCONV tPROC CEXTMAX silabs.com | Smart. Connected. Energy-friendly. Min Typ Max Unit Accumulation = 1x — 64 — µs Accumulation = 4x — 256 — µs Accumulation = 8x — 512 — µs Accumulation = 16x — 1.024 — ms Accumulation = 32x — 2.048 — ms Accumulation = 64x — 4.096 — ms Accumulation = 1x — 90:1 — codes Accumulation = 4x — 180:1 — codes Accumulation = 8x — 182:1 — codes Accumulation = 16x — 210:1 — codes Accumulation = 32x — 230:1 — codes Accumulation = 64x — 270:1 — codes Gain = 1x — 205 — µs Gain = 2x — 123 — µs Gain = 3x — 98 — µs Gain = 4x — 85 — µs Gain = 5x — 76 — µs Gain = 6x — 72 — µs Gain = 7x — 67 — µs Gain = 8x — 64 — µs 1 sensor — 576 — µs 2 sensors — 796 — µs 3 sensors — 1.0 — ms 4 sensors — 1.2 — ms 5 sensors — 1.4 — ms 6 sensors — 1.7 — ms 7 sensors — 1.9 — ms 8 sensors — 2.1 — ms 9 sensors — 2.3 — ms 10 sensors — 2.6 — ms 11 sensors — 2.8 — ms 12 sensors — 3.0 — ms Gain = 8x — 45 — pF Gain = 1x — 500 — pF Preliminary Rev. 0.2 | 7 CPT112S Data Sheet Electrical Specifications Parameter Symbol Test Condition Maximum External Series Impedance REXTMAX Gain = 8x Min Typ Max Unit — 50 — kΩ Note: 1. Measured with gain set to 8x. 2. Measured with an evaluation board with 1/16" overlay using Capacitive Sense Profiler. 3. Sensors configured to 8x gain, 1x accumulation with sensor sampling and system processing time included and mutually-exclusive buttons, slider, buzzer, and touch time-outs disabled. 3.1.6 Buzzer Output Table 3.6. Buzzer Output Parameter Symbol Test Condition Min Typ Max Unit Output High Voltage (High Drive) VOH IOH = –3 mA VDD – 0.7 — — V Output Low Voltage (High Drive) VOL IOL = 8.5 mA — — 0.6 V Output High Voltage (Low Drive) VOH IOH = –1 mA VDD – 0.7 — — V Output Low Voltage (Low Drive) VOL IOL = 1.4 mA — — 0.6 V Weak Pull-Up Current IPU VDD = 1.8 V — –4 — µA –35 –20 — µA Min Typ Max Unit VIN = 0 V VDD = 3.6 V VIN = 0 V 3.2 Thermal Conditions Table 3.7. Thermal Conditions Parameter Symbol Test Condition Thermal Resistance* θJA QFN20 Packages — 60 — °C/W QSOP24 Packages — 65 — °C/W Note: 1. Thermal resistance assumes a multi-layer PCB with any exposed pad soldered to a PCB pad. silabs.com | Smart. Connected. Energy-friendly. Preliminary Rev. 0.2 | 8 CPT112S Data Sheet Electrical Specifications 3.3 Absolute Maximum Ratings Stresses above those listed in Table 3.8 Absolute Maximum Ratings on page 9 may cause permanent damage to the device. This is a stress rating only and functional operation of the devices at those or any other conditions above those indicated in the operation listings of this specification is not implied. Exposure to maximum rating conditions for extended periods may affect device reliability. For more information on the available quality and reliability data, see the Quality and Reliability Monitor Report at http://www.silabs.com/ support/quality/pages/default.aspx. Table 3.8. Absolute Maximum Ratings Parameter Symbol Ambient Temperature Under Bias Test Condition Min Max Unit TBIAS –55 125 °C Storage Temperature TSTG –65 150 °C Voltage on VDD VDD GND–0.3 4.0 V Voltage on I/O pins or RSTb VIN GND–0.3 VDD + 0.3 V Total Current Sunk into Supply Pin IVDD — 400 mA Total Current Sourced out of Ground Pin IGND 400 — mA Current Sourced or Sunk by Any I/O Pin or RSTb IIO –100 100 mA Maximum Total Current through all Port Pins IIOTOT — 200 mA Operating Junction Temperature TJ –40 105 °C Exposure to maximum rating conditions for extended periods may affect device reliability. silabs.com | Smart. Connected. Energy-friendly. Preliminary Rev. 0.2 | 9 CPT112S Data Sheet Electrical Specifications 3.4 Typical Performance Curves Figure 3.1. Active Mode Processing Time Per Sensor Note: Active mode processing time per sensor measured with sensors configured to 1x accumulation, 8x gain. Sensor sampling and system processing time is included with mutually-exclusive buttons, the buzzer, slider, and touch time-outs disabled. Figure 3.2. Current vs. Active Mode Scan Period — Base Current Consumption silabs.com | Smart. Connected. Energy-friendly. Preliminary Rev. 0.2 | 10 CPT112S Data Sheet Electrical Specifications Figure 3.3. Current vs. Active Mode Scan Period — Current Consumption for Each Additional Sensor Note: Active mode scan period current draw measured with free run mode disabled and all 12 sensors enabled at 4x accumulation, 8x gain. In addition, the buzzer, slider, and mutually-exclusive button groups were disabled. Figure 3.4. Typical VOH Curves silabs.com | Smart. Connected. Energy-friendly. Preliminary Rev. 0.2 | 11 CPT112S Data Sheet Electrical Specifications Figure 3.5. Typical VOL Curves silabs.com | Smart. Connected. Energy-friendly. Preliminary Rev. 0.2 | 12 CPT112S Data Sheet Functional Description 4. Functional Description 4.1 Capacitive Sensing Input 4.1.1 Introduction The capacitive to digital converter uses an iterative, charge-timing self-capacitance technique to measure capacitance on an input pin. Sampling is configured and controlled by settings in the non-volatile configuration profile, which can be changed through the 2-pin configuration interface. Capacitance Active threshold Inactive threshold Touch delta Baseline Time Figure 4.1. Capacitive Sense Data Types 4.1.2 Touch Qualification Criteria The device detects a touch event when an inactive (untouched) input enabled by the input enable mask detects an sequence of measurements that cross the active threshold. The device detects a touch release event when an active (touched) input enabled by the input enable mask detects an sequence of measurements that cross the inactive threshold. The debounce configuration profile parameter defines how many measurements in a row must cross a threshold before a touch or release is qualified. In electrically noisy environments more heavily filtered data is used for qualification. 4.1.3 Thresholds Capacitive sensing inputs use input-specific thresholds for touch qualification. Each input uses two thresholds, one to detect inactive-toactive transitions on the input, and another to determine active-to-inactive transitions on the input. The inputs use two thresholds to add hysteresis and prevent active/inactive ringing on inputs. Each threshold can be set through Simplicity Studio tools and all thresholds are stored in non-volatile memory in the device's configuration profile. Thresholds are defined as percentages of a capacitive sensing input's touch delta. silabs.com | Smart. Connected. Energy-friendly. Preliminary Rev. 0.2 | 13 CPT112S Data Sheet Functional Description 4.1.4 Debounce Counter Each capacitive sensing input maintains its own debounce counter. For an inactive sensor, this counter tracks the number of successive samples which have crossed that input's active threshold. For an active sensor, this counter tracks the number of successive samples which have crossed the inactive threshold. When the counter reaches a terminal value defined in the the configuration profile, the touch/release event is qualified. 4.1.5 Touch Deltas Each capacitive sensing input uses a stored touch delta value that describes the expected difference between inactive and active capacitive sensing output codes. This value is stored in the configuration profile for the system and is used by the touch qualification engine, which defines inactive and active thresholds relative to the touch delta. The touch deltas are stored in the configuration profile in a touch delta/16 format. For this reason, touch deltas must be configured as multiples of 16. 4.1.6 Auto-Accumulation and Averaging Capacitive sensing inputs have an auto-accumulate and average post-sample filter that can be used to improve signal strength if needed. Settings stored in the configuration profile can configure the engine to accumulate 1, 4, 8, 16, 32, or 64 samples. After the defined number of samples have been accumulated, the result is divided by either 1, 4, 8, 16, 32, or 64, depending on the accumulation setting. This auto-accumulated and averaged value is the sample output used for all touch qualification processing. Note that sample time per sensor increases as the level of accumulation increases. To reduce current consumption, the engine should not be set to auto-accumulate unless it is required to achieve acceptable signal strength due to thick overlays or other system-level factors. 4.1.7 Drive strength The drive strength of the current source used to charge the electrode being measured by the capacitive sensing input can be adjusted in integer increments from 1x to 8x (8x is the default). High drive strength gives the best sensitivity and resolution for small capacitors, such as those typically implemented as touch-sensitive PCB features. To measure larger capacitance values, the drive strength should be lowered accordingly. The highest drive strength setting that yields capacitive sensing output which does not saturate the sensing engine when the electrode is active (touched) should always be used to maximize input sensitivity. 4.1.8 Active Mode Scan Enable Active mode scanning of capacitive sensing inputs is controlled by an enable setting for each capacitive sensing input. This setting is stored in the configuration profile. 4.1.9 Active Mode Scan Period The capacitive sensing input engine stays in active mode whenever one or more inputs have qualified as active. During this time, the sensors scan at a periodicity defined by the active mode scan period, which is stored in the configuration profile. Every active mode scan pushes new samples through the processing engine, which checks for new touch and release events on all enabled inputs. If free run mode is enabled, the engine will repeatedly scan all enabled inputs during the active mode scan period. In this mode of operation, the active mode scan period is used as a timer to determine how much time has passed since the last qualified active sensor has been seen. When a defined amount of time without a qualified touch event has occurred, the engine switches to a low power mode using the sleep mode scan period, and conserves current. If free run mode is disabled, the engine will enter a low power state after completing one scan of all enabled inputs and processing the resulting samples. The engine will remain in this low power state until it wakes, at a time defined by active mode scan period, to perform another scan. silabs.com | Smart. Connected. Energy-friendly. Preliminary Rev. 0.2 | 14 CPT112S Data Sheet Functional Description 4.1.10 Active Mode Scan Type The active mode scan type, which is stored in the configuration profile, controls whether the capacitive sensing engine in active mode will scan only once during the active mode scan period before going to sleep, or whether the engine will continue scanning as quickly as possible during the active mode scan period, never entering a low power state. For optimal responsiveness, the engine should be configured to run with free run mode enabled. Setting the scan mode to 'free run' causes touch qualification on a new touch to occur as quickly as the scanning engine can convert and process samples on all sensors. In this mode, qualification time is not bounded by active mode scan period, and is only bounded by scanning configuration factors such as the debounce setting, the number of enabled sensors, the accumulation setting on each sensor, and the timing constraints of any enabled component. For optimal current draw when in active mode, the engine should be configured to use the 'one scan per period' mode setting. In this case, touch qualification is bound by the scan period and the debounce setting of the device. Touch Event (t = 0 ms) Active process Optimized Active sample 10 ms 20 ms additional processing 30 ms process debounce count = 1 additional processing sample touch qualified sleep Sleep 40 ms sleep Figure 4.2. Timing and Current — One Sample Per Period Mode Touch Event (t = 0 ms) Active process Optimized Active sample 10 ms additional processing 20 ms process debounce count = 1 30 ms 40 ms additional processing sample touch qualified Sleep Figure 4.3. Timing and Current — Free Run Mode 4.1.11 Sleep Mode Scan Period The sleep mode scan period defines the rate at which a scan of the inputs enabled as wake-up sources are sampled. Each enabled sensor can also be enabled as a wake-up source. After the sleep mode scan completes, the scan is processed for a qualified candidate touch. If a candidate touch is qualified, the system wakes form sleep mode and enters active mode scanning. The sleep mode scan period is stored in the configuration profile and is defined in units of ms. silabs.com | Smart. Connected. Energy-friendly. Preliminary Rev. 0.2 | 15 CPT112S Data Sheet Functional Description 4.1.12 Active Mode and Sleep Mode Transitions Capacitive sensing inputs will stay in active mode until no inputs detect qualified touches for a span of time defined by the counts until sleep parameter stored in the configuration profile. The scan period of enabled inputs is defined by the active mode scan period, also found in the configuration profile. If free run mode is enabled, the active mode sensing engine will remain awake and scanning the sensors as fast as possible. If free run mode is disabled, the engine will put itself into a low power state for the remainder of the active mode scan period, after a scan has completed. When in sleep mode, the sensing engine will wake at a period defined by sleep mode scan period to do a scan on sensors that have been enabled as wakeup sources. If the engine finds a candidate touch in this state, the system reverts to active mode to continue scanning. Note that in systems where a proximity input is selected, the sleep mode scan engine uses conversions on the proximity input instead of sensors enabled as wakeup sources. Touch Delta Devices configured to wake on a touch will attempt to qualify the candidate touch that initiated the sleep-to-active transition. If qualification completes successfully, the device will signal this qualification to the external system. Touch qualification of this candidate touch uses the same active mode thresholds, debounce setting, and active mode scan period settings as any touch that occurs during active mode scanning. touch release new touch sleep scan sees touch, wakes, qualifies touch qualified touch release no touch counter = 0 no touch counter = 1 Device Execution t no touch counter = 2 ... no touch counter = counts before sleep device enters sleep Figure 4.4. Active and Sleep Transitions silabs.com | Smart. Connected. Energy-friendly. Preliminary Rev. 0.2 | 16 CPT112S Data Sheet Functional Description 4.2 I2C Event Buffer Interface 4.2.1 Introduction The event buffer I2C interface provides an event-driven, packetized communication system describing newly qualified events generated by the capacitive sensing input engine. The interface provides access to a first-in-first-out buffer of data packets. When the sensing engine generates these packets and pushes them onto the buffer. The interface then signals a host to indicate that one or more packets are available in the buffer by activating the event buffer interrupt pin. The interrupt pin is defined as active-low and operates as a push-pull digital output. The host reads the packets through an I2C interface, with the host acting as an I2C master. Once all packets have been fully transmitted across the I2C interface, the event buffer interrupt pin is de-activated. The device will remain in active mode until no packets remain in the buffer, even if no sensors have been qualified as active for the period of time defined by the active mode scan period and the counts before sleep value. 4.2.2 Packet retrieval in operational mode When the least significant byte of the CRC of an event packet has been transferred during a master read transaction, that event is popped from the device's buffer. If only a part of the event is read, the event will stay in the buffer and will be transmitted again by the device during the next read. If the host initiates a master read when the device is in operational mode but the interrupt pin is not active, signifying that the device has no events in its buffer to transmit, the device will NACK its slave address on the bus. If the I2C master sends a stop condition on the bus before the entire three-byte packet has been read, the device will not pop the packet from its internal buffer. Instead, the I2C state machine will reset, and the next transaction will begin with the first byte of the same event that was being read in the previous, prematurely-terminated transaction. The I2C event buffer has a depth of 22 events. If the host does not read events promptly after seeing the interrupt pin go active, there is the possibility of a buffer overflow. In the event of an overflow, the I2C engine will discard the oldest events first. New I2C packets will only be generated at the active mode sample rate, and so the buffer will only fill at a maximum of 12 packets (in the case of 12 simultaneous touch/releases) per sample period. If the host runs the I2C bus at 400kHz and reads packets as soon as the interrupt pin activates, all packets can be read from the buffer in 1 to 2 ms, which is faster than the rate at which a new active mode scan sequence can complete. silabs.com | Smart. Connected. Energy-friendly. Preliminary Rev. 0.2 | 17 CPT112S Data Sheet Functional Description 4.2.3 Event Packet Structure Every qualified event detected by the capacitive sensing input engine generates a single packet that can be retrieved by the host processor through the event buffer I2C interface. The packet is an atomic data unit that fully describes the generated event. Note: The bytes in the packet are transmitted MSB first. Each packet has a standard structure that can be parsed by the host. Table 4.1. Standard Packet Structure Byte # Designator 0 I2C Slave Address + read bit 1 Packet counter and event type 2 Event description (byte 1) 3 Event description (byte 2) The packet counter is a 4-bit number stored in the upper bits of byte 1. Each new event will be assigned a counter value that is +1 from the last qualified event. After event 15, the counter wraps back to 0 for the next event. The counter captures the temporal nature of touch events so that a host can reconstruct a sequence of events over time. Also, the host can use the counter value to determine if a packet has been lost due to a buffer overflow. The event type is a 4-bit value describes the originator of the event. For instance, the source could be a capacitive sensing button. The event type is stored in the lower 4 bits of byte 1. The event description bytes define characteristics of the event that have been qualified. Event descriptions are defined relative to the event source. An event source that is a capacitive sensing input will have a defined set of valid event description values. Those same values will mean something different for a different type of event source, such as a slider. Event description values are defined relative to the event type field of byte 1. Touch Event I2C Slave Address + read bit byte 0 Touch Release Event Slider Event event type 0000 byte 1 I2C Slave Address + read bit byte 0 packet counter 0011 event type 0001 byte 1 I2C Slave Address + read bit byte 0 packet counter 0010 packet counter 0100 event type 0010 byte 1 CSxx index reserved byte 2 byte 3 CSxx index reserved byte 2 byte 3 slider position (MSB) slider position (LSB) byte 2 byte 3 Figure 4.5. I2C Event Buffer Packet Structure silabs.com | Smart. Connected. Energy-friendly. Preliminary Rev. 0.2 | 18 CPT112S Data Sheet Functional Description 4.2.4 Defined Event Types The device assigns the following event types to events. Table 4.2. Event Type Mapping Event Type Value Mapping 0 Sensor activity - touch event 1 Sensor activity - release event 2 Slider activity Note that this event type value is stored in the lower 4 bits of the first byte of a packet. The upper 4 bits are a packet counter value. 4.2.5 Description Bytes for Touch Events A touch or release event uses only one byte of the description field. That field identifies which sensor caused the touch or release event as shown below. Table 4.3. Touch or Release Event Sensor Mapping Value Mapping 0 Capacitive sensing input 0 1 Capacitive sensing input 1 2 Capacitive sensing input 2 3 Capacitive sensing input 3 4 Capacitive sensing input 4 5 Capacitive sensing input 5 6 Capacitive sensing input 6 7 Capacitive sensing input 7 8 Capacitive sensing input 8 9 Capacitive sensing input 9 10 Capacitive sensing input 10 11 Capacitive sensing input 11 4.2.6 Description Bytes for Slider Events The slider activity description field uses two bytes to describe the position of the slider, which can be any value between 0 (0x0000) and 65534 (0xFFFE). The most-significant byte of this value is transmitted in the first byte (byte 2 of the event packet), and the least-significant byte is transmitted second (byte 3 of the event packet). When the slider is released, a final slider event will be transmitted with 0xFFFF in the two-byte field. 4.2.7 Event Buffer I2C Slave Address The device's I2C slave address is configurable through the configuration profile. The device will ACK its slave address only when the interrupt pin is low, signalling that a packet is ready to be read by the host. If the interrupt pin is logic high, the device will not ACK its slave address. silabs.com | Smart. Connected. Energy-friendly. Preliminary Rev. 0.2 | 19 CPT112S Data Sheet Functional Description 4.3 Capacitive Proximity Sensing 4.3.1 Wake on Proximity The wake on capacitive proximity detection engine monitors for the presence of a conductive object such as a hand to move within detectable range of the sensor. When the engine detects an object, the device wakes from sleep and can begin qualifying touch events on all sensors enabled for active mode sensing. 4.3.2 Proximity Configuration The proximity sensing feature uses a single sensor input for proximity qualification. The configuration profile stores the pin chosen by the user. The sensor used for proximity qualification should also have a drive strength setting that is as high as possible without saturating the input when no conductive object is in proximity to the proximity sensor. The accumulation setting of the input is also configurable. The proximity threshold controls the sensitivity of the input. A lower threshold setting increases sensitivity and increases the range of the sensor. A proximity sensing input cannot be used for touch qualification, and so the active and inactive thresholds are not used for proximity sensors. Additionally, the proximity input has no effect on other components of the device such as mutually exclusive button groups, buzzer output, touch time out timers, and sliders. 4.4 Slider The device supports creation of a single slider that is composed of two or more capacitive sensing input pins. The pins chosen as slider inputs are assigned to the slider feature through the configuration profile. The configuration profile also stores a value designated as the highest positional value that can be derived by the slider engine. That highest value is used to derive the values of all intermediate positions on the slider array. silabs.com | Smart. Connected. Energy-friendly. Preliminary Rev. 0.2 | 20 CPT112S Data Sheet Functional Description When a capacitive sensing input pin is designated as a slider input, it will no longer function as a 'button' input and will not generate button style touch/release events across the I2C buffer interface. Touching the slider pads and moving a finger along a slider pad generates an event packet of type Slider, with the remaining two bytes of the packet describing the calculated active position of the slider. The range of possible reported slider active positions can be 0 to the maximum value of the slider as defined in the configuration profile, which can be any value between 40 and 65534. The 65535 (0xFFFF) value is reserved for a slider untouched event. Position 0 is always assigned to the lowest CSxx sensor enabled as a slider input. The maximum position value of the slider is assigned to the highest CSxx sensor enabled as a slider input. All slider inputs in between are assumed to be routed to the slider contiguously, lowest to highest. Valid Configuration CS00 CS02 CS04 CS05 increasing slider position Valid Configuration CS03 CS02 CS01 CS00 CS01 CS03 increasing slider position Invalid Configuration CS00 CS02 Figure 4.6. Slider Behavior and Layout Constraints Slider touch qualification uses the same touch deltas and thresholds that are defined in the configuration profile for all enabled sensors. The user should configure slider sensors through the configuration profile, just as one would configure a sensor assigned to a capacitive button. For optimal performance, each sensor used in the slider should have roughly the same touch surface area dimensions. If the touch-timeout feature is enabled, slider-assigned inputs will also be subject to being qualified as releases by the touch-timeout feature. The mutually exclusive button grouping feature does not affect slider-assigned sensors. Even if the mutually exclusive button grouping feature is enabled, multiple slider-assigned sensors can still be used to resolve a finger's position on the slider. 4.5 Touch Time-Out The touch time-out feature can be enabled and disabled through the configuration profile. When enabled, the device will monitor touch event duration on each input independently. When a touch event exceeds a duration specified in the configuration profile, the device forces a release event, even if the user is still actively touching the sensor. silabs.com | Smart. Connected. Energy-friendly. Preliminary Rev. 0.2 | 21 CPT112S Data Sheet Functional Description The feature qualifies a touch release by adding the configured touch delta value for that sensor to the sensor's current baseline value. By doing this, the raw data-to-baseline delta created by the touch will be removed, and the touch qualification engine will see this as a touch release event. When the user removes a finger from a sensor that had been qualified active but has been qualified released through touch timeout, the resulting raw-to-baseline negative delta will be aggressively tracked downward by the baseline, resulting in a sensor that remains sensitive to successive touches. The touch timeout duration is configured globally, so all inputs are monitored for the same touch duration. If both the touch timeout feature and the mutually exclusive button group feature are enabled, the timeout timer will only run on the touch that is externally reported as being active. 4.6 Buzzer Output 4.6.1 Introduction The buzzer output engine produces a square wave of a configurable duration and frequency when a capacitive sensing input goes from inactive to active. The feature can be enabled and disabled through the configuration profile. The configuration profile also includes the settings for active duration and frequency. Device Execution Active process Optimized Active sample additional processing process additional processing sample sleep Sleep sleep No Touch, Buzzer Inactive Figure 4.7. Effects of the Buzzer on Current Draw — Active Mode, No Touch, Buzzer Inactive Device Execution process Active sample additional processing sleep (stall) process sample additional processing sleep (stall) Optimized Active Sleep Touch Detected, Buzzer Active Figure 4.8. Effects of the Buzzer on Current Draw — Active Mode, Touch Detected, Buzzer Active silabs.com | Smart. Connected. Energy-friendly. Preliminary Rev. 0.2 | 22 CPT112S Data Sheet Functional Description 4.6.2 Buzzer Configuration When enabled, buzzer output will appear on the CS11/buzzer pin (pin 10) of the device. When buzzer output is enabled, CS11 is not available for capactive input sensing. When activated, the buzzer will remain active for either the duration specified in the configuration profile, or until the last active sensor has qualified a touch release. The configuration profile supports configuration of output frequencies ranging from 1 kHz to 4 kHz. The configuration profile can configure the buzzer output pin to either push pull mode or open drain mode. 4.7 Mutually Exclusive Buttons When enabled through the configuration profile, this system allows one and only one capacitive sensing input to be qualified as active at a time. The first sensor active will remain the only sensor active until released. The device will internally qualify multiple touch and release events but will not report them. If multiple sensors have been internally qualified as active, the first sensor's touch event will be reported. If a touch event occurs simultaneously on more than one sensor, the touch with the highest touch delta will be reported. If two sensors are qualified as active and the sensor being reported as active qualifies a touch release, the device will report that release and then report a touch qualification on the still-active second sensor. In the case where a device has simultaneously qualified more than two active sensors and the reported active sensor qualifies and reports a release, the remaining qualified sensor with the highest sensor name will then be reported. For example, if sensors CS00, CS01, and CS02 are active with CS00 externally reported as active, after CS00's release, CS02 would be externally reported as an active sensor unless the device has already qualified a touch release on CS02. If both the touch timeout feature and the mutually exclusive button group feature are enabled, the timeout timer will only run on the touch that is externally reported as being active. CS00 CS01 CS02 Device Execution physical touch on pad touch reported by CPT device release reported by CPT device Figure 4.9. Mutually-Exclusive Button Operation silabs.com | Smart. Connected. Energy-friendly. Preliminary Rev. 0.2 | 23 CPT112S Data Sheet Functional Description 4.8 Self Testing 4.8.1 Introduction When the self-test feature is enabled through the configuration profile, the device performs a check on all enabled capacitive sensing inputs upon startup to determine whether the sensing input pins are erroneously shorted to ground or supply. If a short or open is found on a sensor, the self test feature will signal that an error has been found through a port pin. The feature will then disable that sensor before beginning touch qualification scans on all sensors left enabled. 4.8.2 Test Failure Signaling If the self test check reveals an error, the device will toggle the I2C buffer interrupt pin at a frequency of 2 Hz. This toggling will persist for two seconds if the device detects one or more self test errors. 4.9 Configuration Profile The configuration interface is used by the device to configure default values and performance characteristics that effect capacitive sensing. The configuration data can be programmed through the Configuration interface (Config Clk and Config Data pins) using [Configurator] in Simplicity Studio. Several configuration profile templates are available in Simplicity Studio to provide a starting point for development. silabs.com | Smart. Connected. Energy-friendly. Preliminary Rev. 0.2 | 24 CPT112S Data Sheet Pin Definitions 5. Pin Definitions RSTb / Config Clk 5 Config Data 6 CS02 CS03 CS04 CS05 19 18 17 (Top View) GND 10 4 16 CS06 15 CS07 14 CS08 13 CS09 12 GND 11 CS10 CS11 / BUZZER VDD 20 pin QFN 9 3 EB_SDA GND 8 2 EB_SCL CS00 7 1 EB_INT CS01 20 5.1 CPT112S QFN20 Pin Definitions Figure 5.1. CPT112S QFN20 Pinout Table 5.1. Pin Definitions for CPT112S QFN20 Pin Pin Name Description CS01 Analog input Number 1 Capactive sensing input 1 2 CS00 Analog input Capacitive sensing input 0 3 GND Ground 4 VDD Supply power input 5 RSTb / Active-low reset / Config Clk Configuration clock Config Data Configuration data 6 silabs.com | Smart. Connected. Energy-friendly. Preliminary Rev. 0.2 | 25 CPT112S Data Sheet Pin Definitions Pin Pin Name Description EB_INT Push-pull digital output Number 7 Event buffer interrupt pin 8 EB_SCL Open drain digital output Event buffer I2C SCL 9 EB_SDA Open drain digital input Event buffer I2C SDA 10 11 CS11 / Analog input, capacitive sensing input 11 Buzzer Digital output for buzzer CS10 Analog input Capacitive sensing input 10 12 GND Ground 13 CS09 Analog input Capacitive sensing input 9 14 CS08 Analog input Capacitive sensing input 9 15 CS07 Analog input Capacitive sensing input 7 16 CS06 Analog input Capacitive sensing input 6 17 CS05 Analog input Capacitive sensing input 5 18 CS04 Analog input Capacitive sensing input 4 19 CS03 Analog input Capacitive sensing input 3 20 CS02 Analog input Capacitive sensing input 2 silabs.com | Smart. Connected. Energy-friendly. Preliminary Rev. 0.2 | 26 CPT112S Data Sheet Pin Definitions 5.2 CPT112S QSOP24 Pin Definitions CS02 1 24 CS03 CS01 2 23 CS04 CS00 3 22 CS05 N/C 4 21 CS06 GND 5 20 CS07 VDD 6 19 CS08 N/C 7 18 CS09 N/C 8 17 CS10 RSTb / Config Clk 9 16 CS11 / BUZZER Config Data 10 15 N/C EB_INT 11 14 EB_SDA EB_SCL 12 13 N/C 24 pin QSOP (Top View) Figure 5.2. CPT112S QSOP24 Pinout Table 5.2. Pin Definitions for CPT112S QSOP24 Pin Pin Name Description CS02 Analog input Number 1 Capacitive sensing input 2 2 CS01 Analog input Capactive sensing input 1 3 CS00 Analog input Capacitive sensing input 0 4 N/C No Connect (leave this pin floating) 5 GND Ground silabs.com | Smart. Connected. Energy-friendly. Preliminary Rev. 0.2 | 27 CPT112S Data Sheet Pin Definitions Pin Pin Name Description 6 VDD Supply power input 7 N/C No Connect (leave this pin floating) 8 N/C No Connect (leave this pin floating) 9 RSTb / Active-low reset / Config Clk Configuration clock 10 Config Data Configuration data 11 EB_INT Push-pull digital output Number Event buffer interrupt pin 12 EB_SCL Open drain digital output Event buffer I2C SCL 13 N/C No Connect (leave this pin floating) 14 EB_SDA Open drain digital input Event buffer I2C SDA 15 N/C No Connect (leave this pin floating) 16 CS11 / Analog input, capacitive sensing input 11 Buzzer Digital output for buzzer CS10 Analog input 17 Capacitive sensing input 10 18 CS09 Analog input Capacitive sensing input 9 19 CS08 Analog input Capacitive sensing input 9 20 CS07 Analog input Capacitive sensing input 7 21 CS06 Analog input Capacitive sensing input 6 22 CS05 Analog input Capacitive sensing input 5 23 CS04 Analog input Capacitive sensing input 4 24 CS03 Analog input Capacitive sensing input 3 silabs.com | Smart. Connected. Energy-friendly. Preliminary Rev. 0.2 | 28 CPT112S Data Sheet QFN20 Package Specifications 6. QFN20 Package Specifications 6.1 QFN20 Package Dimensions Figure 6.1. QFN20 Package Drawing Table 6.1. QFN20 Package Dimensions Dimension Min Typ Max A 0.50 0.55 0.60 A1 0.00 — 0.05 b 0.20 0.25 0.30 b1 0.275 0.325 0.375 D D2 3.00 BSC 1.6 1.70 e 0.50 BSC e1 0.513 BSC E 3.00 BSC 1.80 E2 1.60 1.70 1.80 L 0.35 0.40 0.45 silabs.com | Smart. Connected. Energy-friendly. Preliminary Rev. 0.2 | 29 CPT112S Data Sheet QFN20 Package Specifications Dimension Min Typ Max L1 0.00 — 0.10 aaa — 0.10 — bbb — 0.10 — ddd — 0.05 — eee — — 0.08 Note: 1. All dimensions shown are in millimeters (mm) unless otherwise noted. 2. Dimensioning and Tolerancing per ANSI Y14.5M-1994. 3. This drawing is based upon JEDEC Solid State Product Outline MO-248 but includes custom features which are toleranced per supplier designation. 4. Recommended card reflow profile is per the JEDEC/IPC J-STD-020 specification for Small Body Components. silabs.com | Smart. Connected. Energy-friendly. Preliminary Rev. 0.2 | 30 CPT112S Data Sheet QFN20 Package Specifications 6.2 QFN20 PCB Land Pattern Figure 6.2. QFN20 PCB Land Pattern Drawing Table 6.2. QFN20 PCB Land Pattern Dimensions Dimension Min Max C1 2.70 C2 2.70 C3 2.53 C4 2.53 E 0.50 REF X1 0.20 0.30 X2 0.24 .034 X3 1.70 1.80 Y1 0.50 0.60 Y2 0.24 0.34 Y3 1.70 1.80 silabs.com | Smart. Connected. Energy-friendly. Preliminary Rev. 0.2 | 31 CPT112S Data Sheet QFN20 Package Specifications Dimension Min Max Note: 1. All dimensions shown are in millimeters (mm) unless otherwise noted. 2. Dimensioning and Tolerancing is per the ANSI Y14.5M-1994 specification. 3. This Land Pattern Design is based on the IPC-7351 guidelines. 4. All metal pads are to be non-solder mask defined (NSMD). Clearance between the solder mask and the metal pad is to be 60 µm minimum, all the way around the pad. 5. A stainless steel, laser-cut and electro-polished stencil with trapezoidal walls should be used to assure good solder paste release. 6. The stencil thickness should be 0.125 mm (5 mils). 7. The ratio of stencil aperture to land pad size should be 1:1 for the perimeter pads. 8. A 2x2 array of 0.75 mm openings on a 0.95 mm pitch should be used for the center pad to assure proper paste volume. 9. A No-Clean, Type-3 solder paste is recommended. 10. The recommended card reflow profile is per the JEDEC/IPC J-STD-020 specification for Small Body Components. 6.3 QFN20 Package Marking 112S TTTT YWW+ Figure 6.3. QFN20 Package Marking The package marking consists of: • 112S – The part number designation. • TTTT – A trace or manufacturing code. The first letter of this code is the hardware revision. • Y – The last digit of the assembly year. • WW – The 2-digit workweek when the device was assembled. • + – Indicates the device is RoHS-compliant. silabs.com | Smart. Connected. Energy-friendly. Preliminary Rev. 0.2 | 32 CPT112S Data Sheet QSOP24 Package Specifications 7. QSOP24 Package Specifications 7.1 QSOP24 Package Dimensions Figure 7.1. QSOP24 Package Drawing Table 7.1. QSOP24 Package Dimensions Dimension Min Typ Max A — — 1.75 A1 0.10 — 0.25 b 0.20 — 0.30 c 0.10 — 0.25 D 8.65 BSC E 6.00 BSC E1 3.90 BSC e 0.635 BSC L theta silabs.com | Smart. Connected. Energy-friendly. 0.40 — 1.27 0º — 8º Preliminary Rev. 0.2 | 33 CPT112S Data Sheet QSOP24 Package Specifications Dimension Min Typ aaa 0.20 bbb 0.18 ccc 0.10 ddd 0.10 Max Note: 1. All dimensions shown are in millimeters (mm) unless otherwise noted. 2. Dimensioning and Tolerancing per ANSI Y14.5M-1994. 3. This drawing conforms to JEDEC outline MO-137, variation AE. 4. Recommended card reflow profile is per the JEDEC/IPC J-STD-020 specification for Small Body Components. silabs.com | Smart. Connected. Energy-friendly. Preliminary Rev. 0.2 | 34 CPT112S Data Sheet QSOP24 Package Specifications 7.2 QSOP24 PCB Land Pattern Figure 7.2. QSOP24 PCB Land Pattern Drawing Table 7.2. QSOP24 PCB Land Pattern Dimensions Dimension Min Max C 5.20 5.30 E 0.635 BSC X 0.30 0.40 Y 1.50 1.60 Note: 1. All dimensions shown are in millimeters (mm) unless otherwise noted. 2. This land pattern design is based on the IPC-7351 guidelines. 3. All metal pads are to be non-solder mask defined (NSMD). Clearance between the solder mask and the metal pad is to be 60 µm minimum, all the way around the pad. 4. A stainless steel, laser-cut and electro-polished stencil with trapezoidal walls should be used to assure good solder paste release. 5. The stencil thickness should be 0.125 mm (5 mils). 6. The ratio of stencil aperture to land pad size should be 1:1 for all perimeter pads. 7. A No-Clean, Type-3 solder paste is recommended. 8. The recommended card reflow profile is per the JEDEC/IPC J-STD-020 specification for Small Body Components. silabs.com | Smart. Connected. Energy-friendly. Preliminary Rev. 0.2 | 35 CPT112S Data Sheet QSOP24 Package Specifications 7.3 QSOP24 Package Marking e3 CPT112S YYWWTTTTTT Figure 7.3. QSOP24 Package Marking The package marking consists of: • CPT112S – The part number designation. • TTTTTT – A trace or manufacturing code. The first letter of this code is the hardware revision. • YY – The last two digits of the assembly year. • WW – The 2-digit workweek when the device was assembled. • e3 – Indicates the device is RoHS-compliant. silabs.com | Smart. Connected. Energy-friendly. Preliminary Rev. 0.2 | 36 CPT112S Data Sheet Relevant Application Notes 8. Relevant Application Notes The following Application Notes are applicable to the CPT112S devices: • AN957: TouchXpress™ Configuration and Profiling Guide — This application note guides developers through the evaluation and configuration process of TouchXpress devices using Simplicity Studio [Xpress Configurator] and [Capacitive Sense Profiler]. • AN447: Printed Circuit Design Notes for Capacitive Sensing Performance — This document describes hardware design guidelines specifically for capacitive sensing applications, including button placement and other layout guidelines. • AN949: TouchXpress™ Programming Guide — This application note discusses the production programming options available for TouchXpress devices. Application Notes can be accessed on the Silicon Labs website (www.silabs.com/interface-appnotes) or in Simplicity Studio using the [Application Notes] tile. silabs.com | Smart. Connected. Energy-friendly. Preliminary Rev. 0.2 | 37 CPT112S Data Sheet Revision History 9. Revision History 9.1 Revision 0.2 August 12th, 2016 Added new revision devices (A02). Added QSOP24 devices, including pinout information and package drawings. Added a paragraph to 4.1.12 Active Mode and Sleep Mode Transitions describing the wake-on-touch behavior. 9.2 Revision 0.1 November 21st, 2015 Initial release. silabs.com | Smart. Connected. Energy-friendly. Preliminary Rev. 0.2 | 38 Table of Contents 1. Feature List and Ordering Information . . . . . . . . . . . . . . . . . . . . . . 1 2. Typical Connection Diagrams . . . . . . . . . . . . . . . . . . . . . . . . . 2 2.1 Signal, Analog, and Power connections . . . . . . . . . . . . . . . . . . . . . 2 2.2 Configuration . . . . . . . . . . . . . . . . . . . . . 3 . . . . . . . . . 3. Electrical Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 3.1 Electrical Characteristics . . . . . 3.1.1 Recommended Operating Conditions 3.1.2 Power Consumption . . . . . . 3.1.3 Reset and Supply Monitor . . . . 3.1.4 Configuration Memory . . . . . 3.1.5 Capacitive Sense . . . . . . . 3.1.6 Buzzer Output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.2 Thermal Conditions . . . 4 4 5 6 6 7 8 . . . . . . . . . . . . . . . . . . . . . . . . . 8 3.3 Absolute Maximum Ratings . . . . . . . . . . . . . . . . . . . . . . . . . 9 3.4 Typical Performance Curves . . . . . . . . . . . . . . . . . . . . . . . . .10 4. Functional Description. . . . . . . . . . . . . . . . . . . . . . . . . . . 13 4.1 Capacitive Sensing Input . . . . . . . 4.1.1 Introduction . . . . . . . . . . . 4.1.2 Touch Qualification Criteria . . . . . . 4.1.3 Thresholds . . . . . . . . . . . 4.1.4 Debounce Counter . . . . . . . . 4.1.5 Touch Deltas . . . . . . . . . . 4.1.6 Auto-Accumulation and Averaging . . . 4.1.7 Drive strength . . . . . . . . . . 4.1.8 Active Mode Scan Enable . . . . . . 4.1.9 Active Mode Scan Period . . . . . . 4.1.10 Active Mode Scan Type . . . . . . 4.1.11 Sleep Mode Scan Period . . . . . . 4.1.12 Active Mode and Sleep Mode Transitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .13 .13 .13 .13 .14 .14 .14 .14 .14 .14 .15 .15 .16 4.2 I2C Event Buffer Interface . . . . . 4.2.1 Introduction . . . . . . . . . 4.2.2 Packet retrieval in operational mode. 4.2.3 Event Packet Structure . . . . . 4.2.4 Defined Event Types . . . . . . 4.2.5 Description Bytes for Touch Events . 4.2.6 Description Bytes for Slider Events . 4.2.7 Event Buffer I2C Slave Address . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .17 .17 .17 .18 .19 .19 .19 .19 4.3 Capacitive Proximity Sensing. 4.3.1 Wake on Proximity . . . 4.3.2 Proximity Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .20 .20 .20 4.4 Slider . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .20 4.5 Touch Time-Out . . . . . . . . . . . . . . . . . . . . . . . . . . . . .21 Table of Contents 39 4.6 Buzzer Output . . . . 4.6.1 Introduction . . . . 4.6.2 Buzzer Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .22 .22 .23 4.7 Mutually Exclusive Buttons . . . . . . . . . . . . . . . . . . . . . . . . .23 4.8 Self Testing . . . . 4.8.1 Introduction . . . . 4.8.2 Test Failure Signaling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .24 .24 .24 4.9 Configuration Profile. . . . . . . . . . . . . . . . . . . . . . . . . . .24 5. Pin Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 . 5.1 CPT112S QFN20 Pin Definitions . . . . . . . . . . . . . . . . . . . . . . .25 5.2 CPT112S QSOP24 Pin Definitions . . . . . . . . . . . . . . . . . . . . . . .27 6. QFN20 Package Specifications. . . . . . . . . . . . . . . . . . . . . . . . 29 6.1 QFN20 Package Dimensions . . . . . . . . . . . . . . . . . . . . . . . .29 6.2 QFN20 PCB Land Pattern . . . . . . . . . . . . . . . . . . . . . . . . .31 6.3 QFN20 Package Marking . . . . . . . . . . . . . . . . . . . . . . . . . .32 7. QSOP24 Package Specifications . . . . . . . . . . . . . . . . . . . . . . . 33 7.1 QSOP24 Package Dimensions . . . . . . . . . . . . . . . . . . . . . . . .33 7.2 QSOP24 PCB Land Pattern . . . . . . . . . . . . . . . . . . . . . . . . .35 7.3 QSOP24 Package Marking . . . . . . . . . . . . . . . . . . . . . . . . .36 8. Relevant Application Notes . . . . . . . . . . . . . . . . . . . . . . . . . 37 9. Revision History . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38 9.1 Revision 0.2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .38 9.2 Revision 0.1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .38 Table of Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39 Table of Contents 40 Simplicity Studio One-click access to MCU and wireless tools, documentation, software, source code libraries & more. Available for Windows, Mac and Linux! IoT Portfolio www.silabs.com/IoT SW/HW www.silabs.com/simplicity Quality www.silabs.com/quality Support and Community community.silabs.com Disclaimer Silicon Laboratories intends to provide customers with the latest, accurate, and in-depth documentation of all peripherals and modules available for system and software implementers using or intending to use the Silicon Laboratories products. Characterization data, available modules and peripherals, memory sizes and memory addresses refer to each specific device, and "Typical" parameters provided can and do vary in different applications. Application examples described herein are for illustrative purposes only. Silicon Laboratories reserves the right to make changes without further notice and limitation to product information, specifications, and descriptions herein, and does not give warranties as to the accuracy or completeness of the included information. Silicon Laboratories shall have no liability for the consequences of use of the information supplied herein. This document does not imply or express copyright licenses granted hereunder to design or fabricate any integrated circuits. The products are not designed or authorized to be used within any Life Support System without the specific written consent of Silicon Laboratories. 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