IQS229-00085000-DNR

ProxSense® Series IQS229 Datasheet Single Channel Capacitive Proximity/Touch Controller for SAR Applications The IQS229 ProxSense® IC is a self-capacitance controller designed for applications that are required to meet SAR regulations. The IQS229 can also be used to detect a long term presence as a movement detector. The IQS229 operates standalone and can be configured via digital inputs. Features           RoHS2 SAR compliance in mobile devices according to the IEC 62209-2 ed1.0 standard and the FCC standard (KDB 616217 - D04 SAR for laptop and tablets v01) Failsafe firmware/hardware design Automatic Tuning (ATI) On-chip movement detection algorithm Minimal external components Standalone operation 25mm detection distance Up to 60pF sensor load Internal Capacitor Implementation (ICI) – reference capacitor on-chip Configuration settings via external pins   Compliant IQS229 DFN10 Representations only, not actual markings     Activation threshold Activation time-out Supply voltage: 1.8V to 3.6V Low power consumption: 30uA (sub 10uA in sleep mode) Low profile DFN10 package (3x3) Movement filter threshold Applications  SAR detection for tablets and mobile phones  SAR detection for wireless charging stations (operating frequency > 100 MHz)  SAR detection devices  Movement detection devices (anti-theft) for USB      dongle-type Reed relay replacement White goods and appliances Human Interface Devices Proximity activated backlighting Applications with long-term activation Available Packages TA DFN10 (3x3) -20°C to 85°C Copyright © Azoteq 2017 All Rights Reserved IQS229 IQS229 Datasheet v1.91 Check for latest datasheet Page 1 of 18 September 2017 ProxSense® Series Figure 1.1 Flow diagram of the IQS229 user interface 1.1.1 Normal operation 1 Overview With a normal activation (hand brought close) the output will become active. The output will de-activate as soon as the action is reversed (hand taken away). In addition a separate movement output will become active when movement is detected according to a movement threshold. Movement may be detected before the normal threshold is crossed. Movement 1.1 Device COUNTS (Capacitance) The IQS229 is a device tailored for longterm proximity or touch activations. It offers two Boolean outputs, one with an activation threshold for large capacitive shifts and the other with a threshold for small movements even during a normal activation. COUNTS (Capacitance) LONG TERM AVERAGE Cross threshold before time-out Threshold Time MOV_OUT pin OUT pin Timer Reset Sensor ACTIVATION RELEASE Figure 1.2 Plot of IQS229 streaming data along with the digital response Copyright © Azoteq 2017 All Rights Reserved IQS229 Datasheet v1.91 Check for latest datasheet Page 2 of 18 September 2017 ProxSense® Series detection is done via a completely separate digital filter while improving the efficiency of the sensor output (timer reset on movement). time-out with no movement around the sensor. 1.1.4 Fail-safe features For SAR application the device includes various features to ensure fail-safe operation: 1.1.2 Long term activation In a normal activation the output will stay active for as long as movements are detected. A time-out timer (configurable time) will be reset with each movement.  Active low with pull-down resistor ensures activation with failure (at the cost of leakage current with no activation)  Hard reset by pulling the movement pin low. This allows for a restart and device status check.  Characteristic toggle on output pin with power-up and soft reset to check if the IC is functioning. 1.1.3 Long term recovery When changing the sensor capacitive environment, the sensor will adapt to the new environment. If the new environment decreases capacitance (wooden table to air), the sensor will rapidly adapt in order to accept new human activations. If the new environment increases capacitance (like air to steel table), the sensor will remain in activation until a time-out occurs (as seen 1.1.5 Integrated features The device includes an internal voltage COUNTS (Capacitance) LTA (LONG TERM AVERAGE) Threshold Below threshold with time-out No movement time-out (default 3min) COUNTS & LTA AutoCalibration Routine (ATI) Time MOV_OUT pin OUT pin Timer Reset Sensor ACTIVATION 0 3min RELEASE No Movement Figure 1.3 Example of a time-out event with re-calibration in Figure 1.3) or until the device is returned to its previous environment. When the timer runs out, the output will be de-activated. Re-calibration is possible after de-activation because the timer will only Copyright © Azoteq 2017 All Rights Reserved regulator and reference capacitor (Cs). Various advanced signal processing techniques are combined for creating a robust solution. IQS229 Datasheet v1.91 Check for latest datasheet Page 3 of 18 September 2017 ProxSense® Series These techniques include:  Movement detection filter (to release an activation in the case of inactivity)  Advanced noise filtering on incoming sample stream  Superior methods of parasitic capacitance compensation while preserving sensitivity 1.1.6 Data streaming A 1-wire data streaming interface is offered for debugging purposes. Streaming mode and stand-alone mode are interchangeable via simple hardware configurations. This is offered because streaming may be useful at various stages of a design. Streaming mode is offered through a simple pull-up resistor on the standard digital output pin. Standalone mode is enabled through a pull-down resistor on this pin. described in the application note: “AZD004 - Azoteq Capacitive Sensing”.) 1.2 Operation 1.2.1 Device Setup Typical device use allows for very little to no setup before integration. A few characteristics may be fixed via four of the IQS229 pins - each having three possible pin states. This should suffice for most simple and intended applications. Note: It is important that any pins connected to an MCU are kept high impedance (Hi-Z) from the MCU side during power-up. This is to ensure correct start-up especially with a high impedance strap resistor on the OUT pin for standalone power-up. 1.2.2 Configuration pin setup Configuration options are selected by: 1.1.7 Hardware configuration options Various configuration options are made available through digital input pins. These include:  the activation threshold,  inactivity time-out settings  and movement threshold selection Special device configurations are only available on special request and can be done by setting one time programmable (OTP) options. These will only be available on special orders, aiming to meet most needs with configuration pins. 1.1.8 Automatic Calibration Proven Automatic Tuning Implementation (ATI) algorithms are used to calibrate the device to the sense electrode. This algorithm is optimised for applications where a fixed detection distance (in mid-air) is required for failure safe detection.  Floating a pin  pull-up resistor  pull-down resistor See section 4 for choosing a specific configuration. For configurations not covered by the configuration pins, custom ICs will be available in bulk orders. Information on custom configurations are available on special request. At start-up device parameters are read and set according to the configuration pin states. Configuration pins are then changed to digital outputs and are written to the state that was read (for minimising current consumption1). Floating pins are written low. After configuration, calibration routines are run which can be run periodically in order to run with optimal sensitivity. 1.2.3 Movement filters The movement filter runs continually and the dedicated digital output will activate for 1.1.9 Capacitive sensing method The charge transfer method of capacitive sensing is employed on the IQS229. (The charge transfer principle is thoroughly Copyright © Azoteq 2017 All Rights Reserved 1 Known issue & workaround: The THR0 and TIMER pin are written low when pulled high. Use a 1MΩ on these pins to limit current consumption. IQS229 Datasheet v1.91 Check for latest datasheet Page 4 of 18 September 2017 ProxSense® Series a time depending on the intensity of the movement. 1.2.4 External control The movement output (optional line to connect to master device) can be used to signal a “reseed” (treseed) or “sleep mode” (tsleep). A short pulse will force the reference counts (long-term average) to match the actual counts (capacitance of sensor). By writing the pin low for a longer time, will force the IC into sleep mode for low current consumption (2uA + required pull-up on movement pin). When sleep mode is entered, the IQS229 will reset upon wakeup. In sleep mode the output pin is written low in order to minimise current consumption. 1.2.5 Low power options As mentioned in the section above, a charge halt will initiate the sleep mode. The device will reset and return to normal power as soon as the line is released. 1.3 Applicability All specifications, except where specifically mentioned otherwise, provided by this datasheet are applicable to the following ranges: Temperature:-20C to +85C Supply voltage (VDDHI): 1.8V to 3.6V 1.4 Passing the SAR qualification testing with the IQS229 For design information on passing the SAR qualification testing with Azoteq movement based sensors, please see the application note: “AZD073 SAR qualification with Azoteq movement-based sensors” Copyright © Azoteq 2017 All Rights Reserved IQS229 Datasheet v1.91 Check for latest datasheet Page 5 of 18 September 2017 ProxSense® Series 2 Packaging and Pin-Out The IQS229 is available in a DFN10 (3x3) package. Pin 1 Marking MOV_OUT TIMER 1 10 VSS 2 9 OUT CRX0 3 8 THR0 VDDHI 4 7 MOV_THR VREG 5 6 THR1 229 Figure 2.1 IQS229 pin-out (DFN10 package) Table 2.1 Pin-out description IQS229 in DFN10 Pin Name Type Function 1 2 TIMER VSS Digital Input Signal GND “No movement” timeout period selection 3 CRX0 Sense electrode 4 5 6 7 8 VDDHI VREG THR1 MOV_THR THR0 Supply Input Regulator output Digital Input Digital Input Digital Input 9 OUT Digital Output/Input 10 MOV_OUT Digital Output/Input Connect to conductive area intended for sensor Supply:1.8V – 3.6V Requires external capacitor Threshold1 selection (fine) Movement Threshold selection Threshold0 selection (coarse) Activation output (active low) / 1-wire Data / Input at power-up to determine standalone or streaming Movement output (active low) / Input for reseed and charge halt 3 Reference Design Figure 3.1 Reference schematic Copyright © Azoteq 2017 All Rights Reserved IQS229 Datasheet v1.91 Check for latest datasheet Page 6 of 18 September 2017 ProxSense® Series 4 Configuration Options 4.1 Activation Threshold The threshold adjustment is offered through two configuration pins. THR0 is a first level of threshold adjustment. THR1 is a second level for refining the threshold. See Table 4.1 for details on choosing the threshold Table 4.1 Threshold adjustment guide L = LOGIC LOW, H = LOGIC HIGH, F = FLOAT THR0 (pin 8) L L L F F F H H H F H L F H L F H 1 2 3 4 5 6 7 8 Entry Threshold Ratio 1/ 512 2/ 512 4/ 512 6/ 512 10/ 512 14/ 512 18/ 512 24/ 512 32/ 512 Corresponding Entry Threshold Countsi 3ii 4 9 14 23 32 42 56 74 Corresponding Release Threshold Counts (counts from reference) 3 3 7 11 ◄More sensitive 18 24 32 42 Large environmental shifts (capacitance increases or decreases) are regarded as activations. Such conditions are intelligently cleared via the movement filter and timer. The timer would reset with each detected movement. If no movement is detected for the duration of the timer, the activation will be cleared. A few options exist for the duration of this timer. TIMER (pin 1) Corresponding Threshold Level 0 4.2 Timer Settings Timer options are a summarized in the table below: THR1 (pin 6) L required, but is not recommended for activation critical applications. Time-out Low 60sec Float 3min High 10min For custom timers the IQS229 makes it possible to distinguish between a threshold release and a no-movement release. The master device may then override the IQS229 output until the custom master timer has expired. OUT pin 56 Less sensitive► It is important to note that most sensitive settings are heavily dependent on design factors influencing SNR. These may be in order where fail-safe activations are OUT pin Figure 4.1 Normal release with threshold crossing (top), time-out release after nomovement condition (bottom) i Assuming a target of 1200 counts, threshold may be more for a larger amount, and less for a smaller amount (usually by only 1 count) ii Threshold calculations limit any threshold value to always be larger than 2 counts Copyright © Azoteq 2017 All Rights Reserved IQS229 Datasheet v1.91 Check for latest datasheet Page 7 of 18 September 2017 ProxSense® Series 4.4 Human movement filter threshold The MOV_THR pin offers adjustment of the threshold used to determine if a movement event should be triggered. From a default setting (pin FLOATING), the threshold can be increased or decreased by a percentage of the capacitive sensor operating point (long-term average). Copyright © Azoteq 2017 All Rights Reserved MOV_THR (pin 7) Movement Threshold Low More sensitive Float Default High Less sensitive IQS229 Datasheet v1.91 Check for latest datasheet Page 8 of 18 September 2017 ProxSense® Series 5 Design Considerations 5.1 Power Layout Supply and 5.3 High Sensitivity PCB Azoteq IC's provide a high level of on-chip hardware and software noise filtering and ESD protection (refer to application note “AZD013 – ESD Overview”). Designing PCB's with better noise immunity against EMI, FTB and ESD in mind, it is always advisable to keep the critical noise suppression components like the de-coupling capacitors and series resistors in Figure 3.1. as close as possible to the IC. Always maintain a good ground connection and ground pour underneath the IC. For more guidelines please refer to the relevant application notes as mentioned in the next section. Through patented design and advanced signal processing, the device is able to provide extremely high sensitivity to detect proximity. This enables designs to detect proximity at distances that cannot be equaled by most other products. When the device is used in environments where high levels of noise or floating metal objects exist, a reduced proximity threshold is proposed to ensure reliable functioning of the sensor. The high sensitivity also allows the device to sense through overlay materials with low dielectric constants, such as wood or porous plastics. For more guidelines on the layout of capacitive sense electrodes, please refer to application note “AZD008 - Design Guidelines for Touch Pads”, available on the Azoteq web page: www.azoteq.com. 5.2 Design Rules for Harsh EMC Environments Applicable application notes: AZD013, AZD015, AZD051, and AZD052. Copyright © Azoteq 2017 All Rights Reserved IQS229 Datasheet v1.91 Check for latest datasheet Page 9 of 18 September 2017 ProxSense® Series 6 1-Wire mode data the PCB. This will put the standalone module in 1-wire streaming mode. streaming Data streaming is initiated by the IQS229. When data streaming is enabled data is sent following each charge cycle. The IQS229 has the capability to stream data over the OUT pin to a master controller or debugging device. This provides the designer with the capability to obtain the parameters within the device in order to aid design into applications. Data streaming is performed as a 1-wire data protocol on the OUT pin. The function of this pin is therefore lost when the device is placed in streaming mode. The function of the MOV_OUT pin remains. The MOV_OUT pin may now be used to only read streaming data when movements occur. This enables 1-wire data processing only on the occurrence of movement events. Figure 6.1 Illustrates the communication protocol for initialising and sending data with the 1 wire communication protocol. 1. Communication is initiated by a START bit. Bit defined as a low condition for tSTART. 2. Following the START bit, is a synchronisation byte (TINIT = 0xAA). This byte is used by the MCU for clock synchronisation. 3. Following TINIT the data bytes will be sent. 20 bytes will be sent after each charge cycle. 4. Each byte sent will be preceded by a START bit and a STOP bit will follow every byte. 5. STOP bit indicated by taking pin 1 high. The STOP bit does not have a defined period. Data streaming can be enabled as shown in Figure 3.1 by simply placing a strong pull-up resistor on the OUT pin (4.7kΩ is recommended). Debugging and qualification during production may be done by simply probing the output pin with a strong pull-up while the weaker pull-down (1MΩ) is placed on TOUT /OUT D7 D19 tINIT tDATA D6 D18 D5 D17 D4 … D3 D3 D2 D2 D1 D1 D0 D0 tSTOP Stop – Start Start Stop – Start Figure 6.1 1-wire data streaming mode Copyright © Azoteq 2017 All Rights Reserved IQS229 Datasheet v1.91 Check for latest datasheet Page 10 of 18 September 2017 ProxSense® Series The following table defines the data streamed Azoteq provides a graphic user interface to from the IQS229 device during streaming evaluate the user interface and debug current designs. mode. Table 6.1 Byte definitions for 1-wire streaming mode Byte 0 16 17 18 Bit 7:0 7 6 5 4 3 2 1 0 15:8 23:16 31:24 39:32 47:40 55:48 63:56 71:64 79:72 87:80 95:88 103:96 111:104 119:112 127:120 127:124 123:122 121:220 135:128 143:136 151:144 19 159:152 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 Copyright © Azoteq 2017 All Rights Reserved Value System Flags Activation Movement Timer Active Filter Halt Is channel 0 ATI tuning busy Noise detected Zoom CH0 CS High byte CH0 CS Low byte CH0 LTA High byte CH0 LTA Low byte CH1 CS High byte CH1 CS Low byte CH1 LTA High byte CH1 LTA Low byte Movement Filter Movement Filter Entry threshold high byte Entry threshold low byte Exit threshold high byte Exit threshold low byte Strap configuration Activation threshold Timer setting Movement threshold Multiplier channel 0 Multiplier channel 1 Parasitic capacitance compensation (PCC) channel 0 Parasitic capacitance compensation (PCC) channel 1 Sample code available: “AZD017 - IQS127 1Wire Protocol SAMPLE CODE” This code represents the same protocol and only needs to be adapted for the longer data stream. IQS229 Datasheet v1.91 Check for latest datasheet Page 11 of 18 September 2017 ProxSense® Series 7 Typical Application 7.1 Minimizing Resistor straps Component count is an important factor for applications with limited space and cost constraints. This section addresses this with a slightly more complex configuration than the standard reference design. This configuration should lead the designer to a safe minimal component design. Hardware Configuration options Pull up IQS229 Less sensitive / Longer timer Float Default/Midway options Digital Input Pull Down More sensitive / Shorter timer Figure 7.1 IQS229 configuration pin options Table 7.1 Table of constraints for resistor strap optimization Resistor strap state Applicable pins Output state after start-up Resistor value Current consumption Combination strap Pull down All input pins Written low when pulled low 1kΩ ≤ R ≤ 2MΩ Only at power-on Yes, all pins Pull up THR0 and TIMER Written low when pulled high 1MΩ ≤ R ≤ 2MΩ Continuous Applicable pins may be combined Pull up THR1 and MOV_THR Written high when pulled high 1kΩ ≤ R ≤ 2MΩ Only at power-on Applicable pins may be combined Figure 7.2 shows the reference design for a minimal resistor layout. With a fixed design, a minimum of 0 strap resistors and maximum of 3 strap resistors are expected. Figure 7.2 Minimal resistor strap configuration Copyright © Azoteq 2017 All Rights Reserved IQS229 Datasheet v1.91 Check for latest datasheet Page 12 of 18 September 2017 ProxSense® Series 8 Specifications 8.1 Absolute maximum ratings The following absolute maximum parameters are specified for the device: Exceeding these maximum specifications may cause damage to the device.  Operating temperature -20°C to 85°C  Supply Voltage (VDDHI – VSS) 3.6V  Maximum pin voltage  Maximum continuous current (for specific Pins) VDDHI + 0.5V (may not exceed VDDHI max) 10mA  Minimum pin voltage VSS - 0.5V  Minimum power-on slope 100V/s  ESD protection ±8kV (Human body model)  Package Moisture Sensitivity Level (MSL) 1 Table 8.1 IQS229 General Operating Conditions DESCRIPTION Supply voltage Internal regulator output Default Operating Current Conditions 1 1.8 ≤ VDDHI≤ 3.6 3.3V PARAMETER VDDHI VREG IIQS229NP MIN 1.8 1.62 - TYP 3.3V 1.7 100 MAX 3.6 1.79 Low Power Setting 1* 3.3V, LP=32 IIQS229LP32 -