sx8661 Semtech Corporation, sx8661 Datasheet
sx8661
Related parts for sx8661
sx8661 Summary of contents
Page 1
... ADVANCED COMMUNICATIONS & SENSING G D ENERAL ESCRIPTION The SX8661 is an ultra low power, fully integrated 8- channel solution for capacitive touch-button and proximity detection applications. capacitive touch solutions, the SX8661 features dedicated capacitive sense inputs (that requires no external components) in addition to 8 general purpose I/O ports (GPIO) ...
Page 2
... I2C interface 3.16 Interrupt 3.16.1 Power up 3.16.2 Assertion Revision v3.2, January 2011 Low Power, Capacitive Button Touch and Proximity Controller (8 sensors) with LED Drivers and Analog Output Table of Contents ............................................................................................................ 1 ............................................................................................................... 5 ................................................................................................. 8 ........................................................................................................ 12 © 2011 Semtech Corp. 2 SX8661 DATASHEET ...
Page 3
... Example of Touch+Proximity Module 7.3.1 Overview 7.3.2 Operation 7.3.3 Performance 7.3.4 Schematics 7.3.5 Layout Revision v3.2, January 2011 Low Power, Capacitive Button Touch and Proximity Controller (8 sensors) with LED Drivers and Analog Output .............................................................................. 43 ...................................................................................................... 79 © 2011 Semtech Corp. 3 SX8661 DATASHEET ...
Page 4
... ADVANCED COMMUNICATIONS & SENSING 8 R ............................................................................................................................. 86 EFERENCES ACKAGING NFORMATION 9.1 Package Outline Drawing 9.2 Land Pattern Revision v3.2, January 2011 Low Power, Capacitive Button Touch and Proximity Controller (8 sensors) with LED Drivers and Analog Output ........................................................................................................ 87 © 2011 Semtech Corp. 4 SX8661 DATASHEET 87 87 www.semtech.com ...
Page 5
... Pinout Diagram Figure 1 NC5B yyww xxxxx R07 yyww = Date Code xxxxx = Semtech lot number R07 = Semtech Code Marking Information Figure 2 © 2011 Semtech Corp. 5 DATASHEET 22 21 gnd 20 gpio5 19 gpio4 18 gpio3 17 gpio2 16 gnd 15 gpio1 14 www.semtech.com SX8661 ...
Page 6
... General Purpose Input/Output 7 Digital Core Decoupling, connect to a 100nF decoupling capacitor Ground Active Low Reset. Connect to VDD if not used. Analog Core Decoupling, connect to a 100nF decoupling capacitor Capacitive Sensor 0 Exposed pad connect to ground Pin description Table 1 © 2011 Semtech Corp. 6 SX8661 DATASHEET www.semtech.com ...
Page 7
... ADVANCED COMMUNICATIONS & SENSING 1.4 Simplified Block Diagram The simplified block diagram of the SX8661 is illustrated in Figure 3. Figure 3 1.5 Acronyms AOI Analog Output Interface ASI Analog Sensor Interface DCV Digital Compensation Value GPO General Purpose Output GPP General Purpose PWM MTP Multiple Time Programmable ...
Page 8
... I2C interface (v) In the event the host processor is reset or undergoes a power OFF/ON cycle recommended that the host also resets the SX8661 and assures that parameters are re-written into the SPM (should these differ to the parameters held in NVM). 2.3 Thermal Characteristics ...
Page 9
... PU when enabled PD I <4mA <12mA OL,GPIO OL I <4mA OL,SDA,INTB time between rising edge VDD and rising INTB © 2011 Semtech Corp. 9 SX8661 DATASHEET Min. Typ. Max. 200 275 70 100 8 17 800 1100 160 220 0.7*VDD VDD + 0.3 VSS - 0.3 0.8 ±1 ...
Page 10
... LED Drivers and Analog Output Conditions type 0402, tolerance +/-50% vdig type 0402, tolerance +/-50% vana type 0402, COG, tolerance +/-5% int type 0402, tolerance +/-50% vdd Electrical Specifications Table 5 © 2011 Semtech Corp. 10 SX8661 DATASHEET Min. Typ. Max. 100 100 1 100 www.semtech.com Unit ...
Page 11
... HIGH t SU;DAT t HD;DAT t SU;STA t HD;STA t SU;STO t BUF t SP I2C Timing Specification Table 6 I2C Start and Stop timing Figure 4 I2C Data timing Figure 5 © 2011 Semtech Corp. 11 SX8661 DATASHEET Min. Typ. Max. Unit 400 KHz 1.3 us 0.6 us 100 0.6 us 0.6 us 0.6 us 500 us 50 ...
Page 12
... UNCTIONAL DESCRIPTION 3.1 Quickstart Application The SX8661 is preconfigured (Quickstart Application) for an application requiring proximity and seven buttons, with one Analog Output Interface and seven LED drivers using PWM fading. Table 7 summarises the default configuration of the eight GPIOs available on the SX8661 Quickstart application. ...
Page 13
... In case a button is touched the corresponding LED will go to 100% of intensity and the AOI voltage level indicates the button that is touched. Revision v3.2, January 2011 Low Power, Capacitive Button Touch and Proximity Controller (8 sensors) with LED Drivers and Analog Output Quickstart LED and AOI reporting Figure 7 © 2011 Semtech Corp. 13 SX8661 DATASHEET www.semtech.com ...
Page 14
... Fading intensity variations can be logarithmic or linear. Interval speed and initial and final light intensity can be selected by the user. The fading is done using a 256 step PWM. The SX8661 has eight individual PWM generators, one for each GPIO pin. ...
Page 15
... In the second period (Processing) the SX8661 processes the sensor data, verifies and updates the GPIO and the I2C. In the third period (Timer) the SX8661 is set in a low power mode and waits until a new cycle starts. Figure 8 shows the different SX8661 periods over time. ...
Page 16
... In most applications the reaction time needs to be fast when fingers are present, but can be slow when no person uses the application. In case the SX8661 is not used for a specific time it will go from Active mode into Doze mode and power will be saved. This time-out is determined by the Passive Timer which can be configured by the user or turned OFF if not required ...
Page 17
... Buzzer The SX8661 has the ability to drive a buzzer (on GPIO5) to provide an audible indication that a button has been touched. The buzzer is driven by a square signal for approximately 30ms (default). During the first phase (15ms) the signal’s frequency is default 4KHz while in the second phase (15ms) the signal’s frequency default is 8KHz. ...
Page 18
... ADVANCED COMMUNICATIONS & SENSING Revision v3.2, January 2011 Low Power, Capacitive Button Touch and Proximity Controller (8 sensors) with LED Drivers and Analog Output Buzzer behavior Figure 12 © 2011 Semtech Corp. 18 SX8661 DATASHEET www.semtech.com ...
Page 19
... Semtech Corp. 19 SX8661 DATASHEET Index Width Index Width Index 161 193 160 192 224 162 194 161 193 225 163 195 162 194 ...
Page 20
... If more than one button is touched the reported depends on the selected button reporting mode parameter ( 5.5). Three reporting modes exist for the SX8661 (All, Single and Strongest). The All reporting mode is applicable only for the I2C reporting (AOI is not available). In All-mode all buttons that are touched are reported in the I2C buttons status bits ...
Page 21
... In Figure 17 the AOI will each time the buzzer is active. The AOI returns then to either the idle mode for one scan period or goes immediately to the PWM button level. In case the SX8661 is set to sleep mode the AOIs will go to 0V. 3.9 Analog Sensing Interface The Analog Sensing Interface (ASI) converts the charge on the sensors into ticks which will be further digitally processed ...
Page 22
... The larger the number the cycles are repeated the larger the signal out of the ADC with improved SNR. The sensitivity is therefore directly related to the number of cycles. The SX8661 allows setting the sensitivity for each sensor individually in applications which have a variety of sensors sizes or different overlays or for fine-tuning performances. The optimal sensitivity is depending heavily on the final application ...
Page 23
... Once the correct compensation values are found these will be stored and used to compensate each CAP pin. If the SX8661 is shut down the compensation values will be lost next power-up the procedure starts all over again. This assures that the SX8661 will operate under any condition. Powering up at e.g. different temperatures will not change the performance of the SX8661 and the host does not have to do anything special ...
Page 24
... Figure 20 shows the building blocks used for configuring the SX8661. The default configuration parameters of the SX8661 are stored in the Quick Start Memory (QSM). This configuration data is setup to a very common application for the SX8661 with 8 buttons. Without any programming or host interaction the SX8661 will start up in the Quick Start Application. ...
Page 25
... QSM or NVM content. The content of the SPM remains valid as long as the SX8661 is powered. After a power down the host needs to re-write the SPM at the next power-up. Figure 22 shows the Host NVM mode. In this mode the host will be able to write the NVM. ...
Page 26
... The writing of the host towards the NVM is not done directly but done in 2 steps (Figure 22). In the first step the host writes to the SPM (as in Figure 21). In the second step the host signals the SX8661 to copy the SPM content into the NVM. ...
Page 27
... NVM burn procedure is completed (may be delayed by 1 scan period), • during reset (power up, hardware RESETB, software reset). 3.16.3 Clearing The clearing of the INTB is done as soon as the host performs a read to any of the SX8661 I2C registers. Revision v3.2, January 2011 Low Power, Capacitive Button Touch and Proximity Controller (8 sensors) with LED Drivers and Analog Output Power Up vs ...
Page 28
... Example A typical example of the assertion and clearing of the INTB and the I2C communication is shown in Figure 24. When a button is touched the SX8661 will assert the interrupt (1). The host will read the SX8661 status information over the I2C (2) and this clears the interrupt. If the finger releases the button the interrupt will be asserted (3), the host reads the status (4) which clears the interrupt ...
Page 29
... As soon as the INTB rises the SX8661 will be ready for I2C communication. 3.17.2 RESETB When RESETB is driven low the SX8661 will reset and start the power up sequence as soon as RESETB is driven high or pulled high. In case the user does not require a hardware reset control pin then the RESETB pin can be connected to VDD. ...
Page 30
... ADVANCED COMMUNICATIONS & SENSING 3.18 General Purpose Input and Outputs The SX8661 offers eight General Purpose Input and Outputs (GPIO) pins which can be configured in any of these modes: - GPP (General Purpose PWM) - GPO (General Purpose Output) - SPO (Special Purpose Output) The input state of the GPIO is only used during the initial phase of the power up period. ...
Page 31
... Low Power, Capacitive Button Touch and Proximity Controller (8 sensors) with LED Drivers and Analog Output LED control in GPP mode Figure 30 GpioMode GpioOutPwrUp GpioPolarity GpioIntensityOn GpioIntensityOff GpioFunction GppPinId GppIntensity SPM/I2C Parameters Applicable in GPP Mode © 2011 Semtech Corp. 31 SX8661 DATASHEET GPP ...
Page 32
... GPIOs configured as GPO will operate as digital outputs which can generate both standard low/high logic levels and PWM low/high duty cycles levels. Typical application is LED ON/OFF control. This is the dual reporting mode. The SX8661 offers additionally a triple reporting mode which allows the reporting of proximity by a medium strong LED intensity (section 3.18.5). ...
Page 33
... OFF) and programming intensity OFF/ON to 0x00 and 0xFF. 3.18.3 GPO Fading The SX8661 supports two different fading modes, namely Single and Continuous. These fading modes can be configured for each GPIO individually. Please see 5.9 “GPIO Parameters” for more information on how to configure this feature ...
Page 34
... SX8661 Index Lin/Log 225/184 224 226/186 225 227/188 226 228/190 227 229/192 228 230/194 229 231/197 230 232/199 231 233/201 232 ...
Page 35
... Semtech Corp. 35 SX8661 DATASHEET 170/92 202/140 169 201 233 171/93 203/142 170 202 234 172/95 204/144 171 203 235 173/96 205/146 172 ...
Page 36
... Revision v3.2, January 2011 Low Power, Capacitive Button Touch and Proximity Controller (8 sensors) with LED Drivers and Analog Output LEDs in triple reporting mode proximity LEDs in triple reporting mode proximity and touch © 2011 Semtech Corp. 36 SX8661 DATASHEET www.semtech.com ...
Page 37
... ADVANCED COMMUNICATIONS & SENSING DESCRIPTIONS 4.1 Introduction This chapter describes briefly the pins of the SX8661, the way the pins are protected, if the pins are analog, digital, require pull up or pull down resistors and show control signals if these are available. 4.2 ASI pins CAP0, CAP1,...,CAP7 The capacitance sensor pins (CAP0, CAP1, ...
Page 38
... Revision v3.2, January 2011 Low Power, Capacitive Button Touch and Proximity Controller (8 sensors) with LED Drivers and Analog Output SX8661 VANA CP VANA CN Simplified diagram of CN and CP Figure 42 VDD SX8661 R_INT INTB Simplified diagram of INTB Figure 43 © 2011 Semtech Corp. 38 SX8661 DATASHEET ASI INT www.semtech.com ...
Page 39
... Revision v3.2, January 2011 Low Power, Capacitive Button Touch and Proximity Controller (8 sensors) with LED Drivers and Analog Output VDD SX8661 SCL Simplified diagram of SCL Figure 44 VDD SX8661 SDA Simplified diagram of SDA Figure 45 © 2011 Semtech Corp. 39 SX8661 DATASHEET SCL_IN SDA_IN SDA_OUT www.semtech.com ...
Page 40
... Low Power, Capacitive Button Touch and Proximity Controller (8 sensors) with LED Drivers and Analog Output VDD SX8661 RESETB Simplified diagram of RESETB controlled by host VDD SX8661 RESETB Simplified diagram of RESETB without host control © 2011 Semtech Corp. 40 SX8661 DATASHEET RESETB_IN RESETB _IN www.semtech.com ...
Page 41
... VDD has protection to GROUND. Figure 48 shows a simplified diagram of the VDD pin. GND The SX8661 has four ground pins all named GND. These pins and the package center pad need to be connected to ground potential. The GND has protection to VDD. Figure 49 shows a simplified diagram of the GND pin. ...
Page 42
... ADVANCED COMMUNICATIONS & SENSING VANA, VDIG The SX8661 has on-chip regulators for internal use (pins VANA and VDIG). VANA and VDIG have protection to VDD and to GND. The output of the regulators needs to be de-coupled with a small 100nF capacitor to ground. Figure 50 shows a simplified diagram of the VANA and VDIG pin. ...
Page 43
... ETAILED ONFIGURATION DESCRIPTIONS 5.1 Introduction The SX8661 configuration parameters are taken from the QSM or the NVM and loaded into the SPM as explained in the chapter ‘functional description’. This chapter describes the details of the configuration parameters of the SX8661. The SPM is split by functionality into 5 configuration sections: • ...
Page 44
... AoiBtnMapLsb AoiLevelBtn0 AoiLevelBtn1 AoiLevelBtn2 AoiLevelBtn3 AoiLevelBtn4 AoiLevelBtn5 AoiLevelBtn6 AoiLevelBtn7 AoiLevelIdle BuzzerCfg BuzzerFreqPhase1 BuzzerFreqPhase2 Reserved MapAutoLight0 MapAutoLight1 MapAutoLight2 MapAutoLight3 MapAutoLightGrp0Msb www.semtech.com SX8661 default QSM value 0x7F 0x64 0x70 0x50 0xA0 0x01 0x0A 0x00 0x80 0x00 0xFF 0x01 0x55 0x55 0xFF 0x2E 0x45 ...
Page 45
... SPM address map: 0x40…0x7F Table 13 © 2011 Semtech Corp. 45 SX8661 DATASHEET Name default QSM value GpioDecTime7_6 0x44 GpioDecTime5_4 0x44 GpioDecTime3_2 0x44 GpioDecTime1_0 0x44 GpioOffDelay7_6 0x00 GpioOffDelay5_4 0x00 ...
Page 46
... Reserved 0x01: 15ms … 0x0D: 195ms … 0xFF: 255 x 15ms Default: 0x0D Defines Passive Timer on Button Information (Figure 9). 0x00: OFF 0x01: 1 second … 0xFF: 255 seconds Default: 0x00 Reserved (0x00) General Parameters Table 14 © 2011 Semtech Corp. 46 SX8661 DATASHEET www.semtech.com ...
Page 47
... Defines the periodic offset compensation. 0x0: OFF (default) 0x1: 1 second 0x2: 2 seconds … © 2011 Semtech Corp. 47 SX8661 DATASHEET Default Button Default Button Default Button Default Button Default Button Default Button Default Button Default Proximity ...
Page 48
... Capacitive Sensors Parameters Table 15 minimum maximum zero seven Number of buttons (with CAP0 = proximity) minimum maximum one eight Number of buttons (with CAP0 = button or disabled) © 2011 Semtech Corp. 48 SX8661 DATASHEET 0x7: 7 seconds 0x8: 16 seconds 0x9: 18 seconds … 0xE: 28 seconds 0xF: 60 seconds www.semtech.com ...
Page 49
... Button examples Figure 52 Approximate Maximum Tick Level (CapProxEnable = OFF) 1000 2000 3000 4000 5000 6000 7000 8000 ASI Maximum Tick Levels Table 18 © 2011 Semtech Corp. 49 SX8661 DATASHEET Approximate Maximum Tick Level (CapProxEnable = ON) 4000 8000 12000 16000 20000 24000 28000 32000 www.semtech.com ...
Page 50
... The periodic offset compensation is done at a defined interval and only if buttons are released. CapProxEnable: The SX8661 is intended to be used with proximity. This register is set by default to ON (0x74). In case proximity is not required then this register should be set to OFF (0x46) and CAP0 Mode should be set to button or disabled. ...
Page 51
... Defines the proximity hysteresis corresponding to a percentage of the CAP0 threshold (defined in Table 15). 0x00: 0% 0x01: 1% … 0x0A: 10% (default) … 0x64: 100% © 2011 Semtech Corp. 51 SX8661 DATASHEET www.semtech.com ...
Page 52
... LED Drivers and Analog Output Description Defines triple or dual mode reporting of proximity on the GPIOs. 0x00: dual mode 0x7F: triple mode (default) Defines the proximity ON intensity index. 0x00: 0 0x01: 1 … 0x64: 100 (default) … 0xFF: 255 Proximity Parameters Table 19 © 2011 Semtech Corp. 52 SX8661 DATASHEET www.semtech.com ...
Page 53
... Defines the button hysteresis corresponding to a percentage of the CAP thresholds (defined in Table 15). All buttons use the same hysteresis. 0x00: 0% 0x01: 1% … 0x0A: 10% (default) … © 2011 Semtech Corp. 53 SX8661 DATASHEET www.semtech.com ...
Page 54
... Defines the long press button timeout on AOI pins (applicable in Single Reporting Mode). The proximity sensor does not trigger the timer. 0x00: OFF (default) 0x01: 1 second … 0xFF: 255 seconds Button Parameters Table 20 © 2011 Semtech Corp. 54 SX8661 DATASHEET www.semtech.com ...
Page 55
... In the example of Figure 53 the touch is validated after 2 ticks ( The release is detected immediately ( hysteresis. BtnCfg The SX8661 button and proximity interface has three modes of operation: • Report All: reports all touches of multiple fingers and proximity detection. • Report Single: reports only a single touch and/or proximity. Subsequent touches are ignored until the first touch is released. On the AOI proximity is implicit in case of a button touch. • ...
Page 56
... ADVANCED COMMUNICATIONS & SENSING In case the debounce is enabled the SX8661 will count up to the number of debounce samples BtnCfg [1:0], BtnCfg [3:2] before taking a touch or release decision. The sample period is identical to the scan period. BtnAvgPosThresh Small environmental and system noise cause the ticks to vary slowly around the zero idle mode value. ...
Page 57
... CAP0 Hysteresis As a result of that, the output of the SX8661 device would also change very quickly as each of the two sensors becomes the sensor with the strongest touch value. To eliminate this jitter, the SX8661 device adds a hysteresis element to the calculation of the strongest touch sensor. In that respect, the strongest CAP sensor is calculated as the sensor whose value is greater that the second detected strongest CAP sensor by the Strongest hysteresis amount ...
Page 58
... The I2C status and GPO are not affected by this timer (i.e. they will be updated when the button is actually released). Revision v3.2, January 2011 Low Power, Capacitive Button Touch and Proximity Controller (8 sensors) with LED Drivers and Analog Output © 2011 Semtech Corp. 58 SX8661 DATASHEET www.semtech.com ...
Page 59
... Default AoiLevelBtn0: 0xFF 7:0 Default AoiLevelBtn1: 0x2E 7:0 Default AoiLevelBtn2: 0x45 Default AoiLevelBtn3: 0x5D 7:0 Default AoiLevelBtn4: 0x74 Default AoiLevelBtn5: 0x8B 7:0 Default AoiLevelBtn6: 0xA3 Default AoiLevelBtn7: 0xBA Default AoiLevelIdle: 0xFF. AOI Parameters Table 22 © 2011 Semtech Corp. 59 SX8661 DATASHEET www.semtech.com ...
Page 60
... Maximum Voltage (VDD)) * AoiPmwPeriod ≈ (0.3/3.3) * 255 ≈ Write 0x17 in the register AoiBtn0DutyCycle. Revision v3.2, January 2011 Low Power, Capacitive Button Touch and Proximity Controller (8 sensors) with LED Drivers and Analog Output AoiLevelBtn2, AoiLevelBtn3, 23 decimal ≈ © 2011 Semtech Corp. 60 DATASHEET AoiLevelBtn4, AoiLevelBtn5, www.semtech.com SX8661 AoiLevelBtn6, ...
Page 61
... Defines the frequency for the first phase of the buzzer. freq ≈ 4MHz /(2^prescaler * BuzzerFreqPhase1) Default: 0x40 (4KHz) 7:0 Defines the frequency for the second phase of the buzzer. freq ≈ 4MHz /(2^prescaler * BuzzerFreqPhase2) Default: 0x20 (8KHz) 7:0 Reserved (0x00) Buzzer Parameters Table 23 © 2011 Semtech Corp. 61 SX8661 DATASHEET www.semtech.com ...
Page 62
... All sensors events within the group can be independently set. Default: 0x00 Defines Group1 sensor events: 0: OFF any of the enabled sensor events occurs the Group0 event will occur as well. All sensors events within the group can be independently set. Default: 0x00 www.semtech.com SX8661 ...
Page 63
... MapAutoLight3[3:0] should be set to 0x0C (i.e. Group0). - MapAutoLightGrp0 should be set to 0x0003 (i.e. Btn0 or Btn1) Revision v3.2, January 2011 Low Power, Capacitive Button Touch and Proximity Controller (8 sensors) with LED Drivers and Analog Output GPO ON Touch Autolight Mapping, Sensor Information © 2011 Semtech Corp. 63 SX8661 DATASHEET GPO OFF Release www.semtech.com ...
Page 64
... Enables Autolight in GPO mode OFF Default: 0xFF 7:0 Defines the polarity of the GPO and GPP pins. SPO pins require Normal Polarity. 0: Inverted © 2011 Semtech Corp. 64 SX8661 DATASHEET Default AOI-A Default GPO Default GPO Default GPO Default GPO Default GPO Default GPO Default GPO www ...
Page 65
... GPIO[5] OFF Delay 3:0 GPIO[4] OFF Delay 7:4 GPIO[3] OFF Delay 3:0 GPIO[2] OFF Delay 7:4 GPIO[1] OFF Delay 3:0 GPIO[0] OFF Delay © 2011 Semtech Corp. 65 SX8661 DATASHEET Defines the fading increment time. 0x0: OFF 0x1: 0.5ms 0x2: 1ms … 0xF: 7.5ms The total fading in time will be: GpioIncTime*GpioIncFactor* (GpioIntensityOn – ...
Page 66
... Fading mode for GPIO[5] 1:0 Fading mode for GPIO[4] 7:6 Fading mode for GPIO[3] 5:4 Fading mode for GPIO[2] 3:2 Fading mode for GPIO[1] 1:0 Fading mode for GPIO[0] © 2011 Semtech Corp. 66 SX8661 DATASHEET Default: 0x00000000 Enables pullup/down resistors for GPIO pins None 01 : Pullup 10 : Pulldown 11 : Reserved Default: 0x0000 Defines the Fading mode for GPO[7:0] ...
Page 67
... Low Power, Capacitive Button Touch and Proximity Controller (8 sensors) with LED Drivers and Analog Output GPP GPO Applicable SPM/I2C Parameters vs. GPIO Mode © 2011 Semtech Corp. 67 DATASHEET SPO 5 X 2,3 4 www.semtech.com SX8661 ...
Page 68
... After the start condition [S], the slave address (SA) is sent, followed by an eighth bit (‘0’) indicating a Write. The SX8661 then acknowledges [A] that it is being addressed, and the master sends an 8 bit Data Byte consisting of the SX8661 Register Address (RA). The slave acknowledges [A] and the master sends the appropriate 8 bit Data Byte (WD0) ...
Page 69
... The SX8661 responds with acknowledge [A] and the Read Data byte (RD0). If the master needs to read more data it will acknowledge [A] and the SX8661 will send the next read byte (RD1). This sequence can be repeated until the master terminates with a NACK [N] followed by a stop [P]. ...
Page 70
... Reserved SpmKeyMsb read/write SpmkeyLsb read/write SoftReset read/write Table 27 I2C Registers Overview © 2011 Semtech Corp. 70 SX8661 DATASHEET Description Interrupt Source Button Status SPM Status Compensation and Operating Mode GPO Control GPP Pin Selection GPP Intensity SPM Configuration SPM Base Address ...
Page 71
... Buttons/Proximity interrupt flag 1 Compensation interrupt flag 0 Operating Mode interrupt flag Interrupt Source Table 28 © 2011 Semtech Corp. 71 SX8661 DATASHEET Interrupt source flags 0: Inactive (default) 1: Active INTB goes low if any of these bits is set. More than one bit can be set. Reading IrqSrc clears it together with INTB ...
Page 72
... Once – NVM is used if NvmValid = 1, else QSM. NvmCount 2: Twice – NVM is used if NvmValid = 1, else QSM. 3: Three times – NVM is used if NvmValid = 1, else QSM. 4: More than three times – QSM is used I2C SPM status Table 30 © 2011 Semtech Corp. 72 DATASHEET Status of individual buttons 0: Released (default) 1: Touched www.semtech.com SX8661 ...
Page 73
... I2C compensation, operation modes Bits Description Triggers ON/OFF state of GPOs when Autolight is OFF 0: OFF (i. IntensityOff (i. IntensityOn) 7:0 GpoCtrl[7:0] Default is set by SPM parameter GpioOutPwrUp Bits of non-GPO pins are ignored. I2C GPO Control Table 32 © 2011 Semtech Corp. 73 SX8661 DATASHEET www.semtech.com ...
Page 74
... Reading returns the intensity index of the GPP pin selected in GppPinId. Default value is IntensityOn or IntensityOff depending on GpioOutPwrUp. I2C GPP Intensity Table 34 Description Writing 0xDE followed by 0x00 will reset the chip. I2C Soft Reset Table 35 © 2011 Semtech Corp. 74 SX8661 DATASHEET www.semtech.com ...
Page 75
... ADVANCED COMMUNICATIONS & SENSING 6.6 SPM Gateway Registers The SX8661 I2C interface offers two registers for exchanging the SPM data with the host. • SpmCfg • SpmBaseAddr Address Name 0x0D SpmCfg Address Name 0x0E SpmBaseAddr The exchange of data, read and write, between the host and the SPM is always done in bursts of eight bytes. ...
Page 76
... I2C register. At the same time the bit GenStatMsb[6], indicating the SPM write is done, will be cleared. Revision v3.2, January 2011 Low Power, Capacitive Button Touch and Proximity Controller (8 sensors) with LED Drivers and Analog Output SPM write sequence Figure 58 © 2011 Semtech Corp. 76 SX8661 DATASHEET www.semtech.com ...
Page 77
... I2C register. At the same time the bit GenStatMsb[6], indicating the SPM write is done, will be cleared. Revision v3.2, January 2011 Low Power, Capacitive Button Touch and Proximity Controller (8 sensors) with LED Drivers and Analog Output SPM Read Sequence Figure 59 © 2011 Semtech Corp. 77 SX8661 DATASHEET www.semtech.com ...
Page 78
... Figure 60 shows the simplified diagram of the NvmCycle counter. The SX8661 is delivered with empty NVM and NvmCycle set to zero. The SPM points to the QSM. Each NVM burn will increase the NvmCycle. At the fourth NVM burn the SX8661 switches definitely to the QSM. The burning of the SPM into the NVM is done by executing a special sequence of four I2C commands. ...
Page 79
... If a sensor is touched then only the corresponding LED will light up with full intensity. The other LEDs remain at medium intensity. Revision v3.2, January 2011 Low Power, Capacitive Button Touch and Proximity Controller (8 sensors) with LED Drivers and Analog Output © 2011 Semtech Corp. 79 SX8661 DATASHEET www.semtech.com ...
Page 80
... Two AOIs and two LEDs are used. One LED is showing proximity and the second LED (or multiple LEDs) for showing any touch. Figure 63 Revision v3.2, January 2011 Low Power, Capacitive Button Touch and Proximity Controller (8 sensors) with LED Drivers and Analog Output Typical Application (two AOI), dual proximity reporting © 2011 Semtech Corp. 80 SX8661 DATASHEET www.semtech.com ...
Page 81
... LED Drivers and Analog Output dual proximity LED and AOI reporting AOI-A prox idle key1 0.6V key2 0.9V key3 1.2V key4 idle key5 idle key6 idle key7 idle example AOI-A, AOIB Table 40 © 2011 Semtech Corp. 81 SX8661 DATASHEET AOI-B idle idle idle idle 1.5V 1.8V 2.1V 2.4V www.semtech.com ...
Page 82
... Semtech Corp. 82 SX8661 DATASHEET Value[Hex] 0xFE 0x00 0x00 0xF0 0x00 0xFF 0xFF 0xFF 0xFF 0xFF 0xFF 0xFF 0xFF 0x00 0x00 0x00 0x00 ...
Page 83
... Example of Touch+Proximity Module 7.3.1 Overview To demonstrate the proximity sensing feature of the SX8661/SX863x family, a module has been designed and is illustrated in figure below. The touch button controller is running in stand-alone (i.e. without host) and uses the Autolight mode to turn LEDs ON/OFF accordingly to the touch buttons and proximity sensing status. ...
Page 84
... Table 41 7.3.4 Schematics Figure 67 Revision v3.2, January 2011 Low Power, Capacitive Button Touch and Proximity Controller (8 sensors) with LED Drivers and Analog Output Distance of Detection Palm Proximity Sensing Distance of Detection Touch+Proximity Module Schematics © 2011 Semtech Corp. 84 SX8661 DATASHEET ~10cm ~6cm ~4cm www.semtech.com ...
Page 85
... Revision v3.2, January 2011 Low Power, Capacitive Button Touch and Proximity Controller (8 sensors) with LED Drivers and Analog Output Touch+Proximity Module Layout - Top Touch+Proximity Module Layout - Mid1 Touch+Proximity Module Layout - Mid2 Touch+Proximity Module Layout - Bottom © 2011 Semtech Corp. 85 SX8661 DATASHEET www.semtech.com ...
Page 86
... ADVANCED COMMUNICATIONS & SENSING 8 R EFERENCES [1] Capacitive Touch Sensing Layout guidelines on www.semtech.com Revision v3.2, January 2011 Low Power, Capacitive Button Touch and Proximity Controller (8 sensors) with LED Drivers and Analog Output © 2011 Semtech Corp. 86 SX8661 DATASHEET www.semtech.com ...
Page 87
... P I ACKAGING NFORMATION 9.1 Package Outline Drawing SX8661 is assembled in a MLPQ-UT28 package as shown in Figure 72. 9.2 Land Pattern The land pattern of MLPQ-UT28 package shown in Figure 73. Revision v3.2, January 2011 Low Power, Capacitive Button Touch and Proximity Controller (8 sensors) with LED Drivers and Analog Output ...
Page 88
... Advanced Communications and Sensing Products Division 200 Flynn Road, Camarillo, CA 93012 Phone: (805) 498-2111 Fax: (805) 498-3804 Revision v3.2, January 2011 Low Power, Capacitive Button Touch and Proximity Controller (8 sensors) with LED Drivers and Analog Output © 2011 Semtech Corp. 88 SX8661 DATASHEET www.semtech.com ...