TouchXpress™ Family CPT007B Data Sheet The CPT007B device, part of the TouchXpress family, is designed to quickly replace mechanical buttons with modern capacitive touch buttons by eliminating firmware complexity and reducing development time. Supporting up to 7 capacitive sensor inputs in a 3 mm x 3 mm QFN package, the CPT007B is a highly-integrated device that provides a simple solution for adding capacitive touch. The device also comes with advanced features like moisture immunity, wakeon 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 CPT007B device enables rapid user interface designs with minimal development effort. The CPT007B device is ideal for a wide range of capacitive touch applications, including the following: • Home appliances • Instrument / Control panels • White goods Input Features KEY FEATURES • No firmware development required • Simple GUI-based configurator • 7 Capacitive Sensor inputs with programmable sensitivity • 7 General purpose outputs (GPOs) to communicate to the host processor or drive LEDs • 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 • Medical equipment • Consumer electronics • Lighting control • Button touch time-out to avoid false touches • Buzzer output for audible touch feedback Capacitive Touch Sensing Features Output Features Proximity Wake Input Touch Qualification MutuallyExclusive Touch Qualifier Configurable Output Pin for each Input Input Engine with 7 Inputs Configuration Profile for each Input Baselining Optional Buzzer Output 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. 0.1 CPT007B Data Sheet Feature List and Ordering Information 1. Feature List and Ordering Information The CPT007B has the following features: • Capacitive sensing input engine with 7 inputs • Post-sample touch qualification engine • Configuration profile space in non-volatile memory • Pin output with configurable polarity and drive strength • 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 CP T 0 07 B – A 01 – G M R Tape and Reel (Optional) Package Type — QFN20 (M) Temperature Grade — –40 to +85 °C (G) Firmware Revision Hardware Revision Capacitive Sense Features — Button (B) Number of Capacitive Sense Inputs Interface Type — GPO (0), I2C (1) TouchXpress Family Silicon Labs Xpress Product Line Figure 1.1. CPT007B Part Numbering silabs.com | Smart. Connected. Energy-friendly. Preliminary Rev. 0.1 | 1 CPT007B 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 CPT007B devices. CPT007B 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 Host Processor OUT00 OUT01 ... OUT06 CS00 Electrode ... CS06 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. 0.1 | 2 CPT007B 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. CPT007B Device VDD 1k Config Clk Config Data GND ToolStick Figure 2.2. Configuration Connection Diagram silabs.com | Smart. Connected. Energy-friendly. Preliminary Rev. 0.1 | 3 CPT007B 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. 0.1 | 4 CPT007B 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 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. 0.1 | 5 CPT007B 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 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. 0.1 | 6 CPT007B 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 SNR tCONV tPROC Maximum External Capacitive Load CEXTMAX Maximum External Series Impedance REXTMAX 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 Gain = 8x — 45 — pF Gain = 1x — 500 — pF Gain = 8x — 50 — kΩ Preliminary Rev. 0.1 | 7 CPT007B Data Sheet Electrical Specifications Parameter Symbol Test Condition Min Typ Max Unit 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, buzzer, and touch time-outs disabled. 3.1.6 General Purpose and Buzzer Outputs Table 3.6. General Purpose and Buzzer Outputs 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 — 60 — °C/W VIN = 0 V VDD = 3.6 V VIN = 0 V 3.2 Thermal Conditions Table 3.7. Thermal Conditions Parameter Symbol Thermal Resistance* θJA Test Condition 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. 0.1 | 8 CPT007B 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. 0.1 | 9 CPT007B 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, 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. 0.1 | 10 CPT007B 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 7 sensors enabled at 4x accumulation, 8x gain. In addition, the buzzer and mutually-exclusive button groups were disabled. Figure 3.4. Typical VOH Curves silabs.com | Smart. Connected. Energy-friendly. Preliminary Rev. 0.1 | 11 CPT007B Data Sheet Electrical Specifications Figure 3.5. Typical VOL Curves silabs.com | Smart. Connected. Energy-friendly. Preliminary Rev. 0.1 | 12 CPT007B 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. 0.1 | 13 CPT007B 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. 0.1 | 14 CPT007B 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. 0.1 | 15 CPT007B 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. Touch Delta 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 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 4.2 Pin Output 4.2.1 Introduction Results of the capacitive sensing touch qualification engine are communicated through a set of digital output pins. The state of each pin is bound to the touch qualification status of one capacitive sensing input pin. If a capacitive sensing input has qualified an active event, the corresponding output pin will be set to its active state. If the input has qualified a release event is inactive, the corresponding output pin will be set to its inactive state. Pin polarity and drive strength are configurable parameters. silabs.com | Smart. Connected. Energy-friendly. Preliminary Rev. 0.1 | 16 CPT007B Data Sheet Functional Description 4.2.2 Configuration The configuration profile allows users to globally configure outputs as active high or active low. The configuration profile also allows users to globally configure pins as open drain outputs or push-pull outputs. 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 Sensing Output Proximity sensing state is output using a designated Out pin on the CPT007B. By choosing this pin, the user is effectively disabling the corresponding CS input pin. If the user is configuring proximity sensing to mode 2 operation, where a single capacitive sensing input pin is used for proximity detection, it is recommended that this input pin be the pin that corresponds to the selected proximity Out pin. 4.3.3 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 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. 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. 4.5 Buzzer Output 4.5.1 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. silabs.com | Smart. Connected. Energy-friendly. Preliminary Rev. 0.1 | 17 CPT007B Data Sheet Functional Description Device Execution Active process Optimized Active sample additional processing process additional processing sample sleep Sleep sleep No Touch, Buzzer Inactive Figure 4.5. 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 4.6. Effects of the Buzzer on Current Draw — Active Mode, Touch Detected, Buzzer Active 4.5.2 Buzzer Configuration If enabled, buzzer output will be routed to the Buzzer pin (pin 7) of the CPT007B. 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. 4.6 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. silabs.com | Smart. Connected. Energy-friendly. Preliminary Rev. 0.1 | 18 CPT007B Data Sheet Functional Description 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 4.7. Mutually-Exclusive Button Operation 4.7 Self Testing 4.7.1 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. 4.7.2 Test Failure Signaling If the self test check reveals an error, the device will toggle the buzzer output pin at a frequency of 2 Hz. This toggling will persist for two seconds if the device detects one or more self test errors. silabs.com | Smart. Connected. Energy-friendly. Preliminary Rev. 0.1 | 19 CPT007B Data Sheet Functional Description 4.8 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. 0.1 | 20 CPT007B Data Sheet Pin Definitions RSTb / Config Clk 5 Config Data 6 CS02 CS03 CS04 CS05 19 18 17 (Top View) GND 10 4 16 CS06 15 OUT00 14 OUT01 13 OUT02 12 GND 11 OUT03 OUT04 VDD 20 pin QFN 9 3 OUT05 GND 8 2 OUT06 CS00 7 1 BUZZER CS01 20 5. Pin Definitions Figure 5.1. CPT007B Pinout Table 5.1. Pin Definitions for CPT007B-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. 0.1 | 21 CPT007B Data Sheet Pin Definitions Pin Pin Name Description Buzzer Push-pull output Number 7 Buzzer output 8 OUT06 Push-pull output Sensing state of CS06 9 OUT05 Push-pull output Sensing state of CS05 10 OUT04 Push-pull output Sensing state of CS04 11 OUT03 Push-pull output Sensing state of CS03 12 GND Ground 13 OUT02 Push-pull output Sensing state of CS02 14 OUT01 Push-pull output Sensing state of CS01 15 OUT00 Push-pull output Sensing state of CS00 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. 0.1 | 22 CPT007B 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. 0.1 | 23 CPT007B 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. 0.1 | 24 CPT007B 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. 0.1 | 25 CPT007B 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 007B TTTT YWW+ Figure 6.3. QFN20 Package Marking The package marking consists of: • 007B – 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. 0.1 | 26 CPT007B Data Sheet Relevant Application Notes 7. Relevant Application Notes The following Application Notes are applicable to the CPT007B 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. 0.1 | 27 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 General Purpose and Buzzer Outputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 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 Pin Output . . 4.2.1 Introduction . 4.2.2 Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16 .16 .17 4.3 Capacitive Proximity Sensing. 4.3.1 Wake on Proximity . . . 4.3.2 Proximity Sensing Output . 4.3.3 Proximity Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .17 .17 .17 .17 4.4 Touch Time-Out . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .17 4.5 Buzzer Output . . . . 4.5.1 Introduction . . . . 4.5.2 Buzzer Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .17 .17 .18 4.6 Mutually Exclusive Buttons . . . . . . . . . . . . . . . . . . . . . . . . .18 4.7 Self Testing . . . . . . . . . . . . . . . . . . . . . . . . .19 Table of Contents 28 . . . . . . . . . 4.7.1 Introduction . . . . 4.7.2 Test Failure Signaling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19 .19 4.8 Configuration Profile. . . . . . . . . . . . . . . . . . . . . . . . . . .20 5. Pin Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 6. QFN20 Package Specifications. . . . . . . . . . . . . . . . . . . . . . . . 23 . 6.1 QFN20 Package Dimensions . . . . . . . . . . . . . . . . . . . . . . . .23 6.2 QFN20 PCB Land Pattern . . . . . . . . . . . . . . . . . . . . . . . . .25 6.3 QFN20 Package Marking . . . . . . . . . . . . . . . . . . . . . . . . . .26 7. Relevant Application Notes . . . . . . . . . . . . . . . . . . . . . . . . . 27 Table of Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 Table of Contents 29 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 Quality Support and Community www.silabs.com/simplicity www.silabs.com/quality 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. 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