STMPE1208SQTR STMicroelectronics, STMPE1208SQTR Datasheet

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... Home entertainment systems ■ Domestic appliances Table 1. Device summary Order code STMPE1208SQTR December 2009 Description The STMPE1208S is a 12-channel GPIO capacitive touchkey sensor able to interface a main digital ASIC via the two-line bidirectional bus (I changes in capacitance using a fully digital architecture, giving fast and accurate results at very low power consumption ...

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Contents Contents 1 Pin configuration and function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 ...

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STMPE1208S 11 Revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ...

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List of tables List of tables Table 1. Device summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ...

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STMPE1208S List of figures Figure 1. STMPE1208S pin configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ...

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Pin configuration and function 1 Pin configuration and function Figure 1. STMPE1208S pin configuration S_IN_2 S_IN_1 S_IN_0 RESET_N ID_1 ID_0 GPIO_ 5 GPIO_ 4 GPIO_ 3 GPIO_ 2 Table 2. Pin assignments and description Pin number ...

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STMPE1208S Table 2. Pin assignments and description (continued) Pin number Pin ...

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Pin configuration and function Figure 2. STMPE1208S block diagram ID_0 ID_1 RESET G_INT T_INT SDAT SCLK BEEP Figure 3. Application diagram 8/47 Automatic Data filtering unit calibration unit Host interface unit BEEP generator Regulator Clock control unit & power control ...

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STMPE1208S 1.1 Power management The STMPE1208S operates in 3 states. Figure 4. STMPE1208S operating states RESET Host command SLEEP On reset, the STMPE1208S enters the active state immediately. Upon a fixed period of inactivity, the device enters into the IDLE ...

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Clock setting 2 Clock setting The STMPE1208S uses a flexible clocking system that allows the user to adjust the clock speed for optimization of power consumption. Table 3. Clocking system OSC 00 01 1.6 MHz 10 11 The clock frequency ...

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STMPE1208S interface The features that are supported by the I 2 ● slave device ● Compliant to Philips I ● Supports standard (up to 100 kbps) and fast (up to 400 kbps) modes. ● ...

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I2C interface the SDATA low to acknowledge the receipt of the eight bits of data.The receiver may leave the SDATA in high state if it would to not acknowledge the receipt of the data. 3.4 Data Input The device samples ...

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STMPE1208S Figure 5. Read and write modes (random and sequential) One byte Read More than one byte Read One byte Write More than one byte Read Reg Device Device Address Address Address Reg Device Device Address Address Address Data Device ...

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Power schemes 4 Power schemes The STMPE1208S can be powered by a 2.5 V supply directly, or 3.0 - 5.5 V supply through the internal voltage regulator. Figure 6. Power using the internal regulator 1. REG_DISABLE bit in CTRL_2 register ...

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STMPE1208S 5 Capacitive sensors The STMPE1208S capacitive sensor is based on fully digital, impedance change detection engine that is capable of detecting very small change in capacitance. Figure 8. Capacitive sensors Touchkey Impedance sensor 5.1 Capacitive sensing The STMPE1208S senses ...

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Capacitive sensors 5.2 Capacitance compensation The STMPE1208S is capable to measuring capacitance difference between the reference point (Zref) and the individual channels. In the case where the PCB connection between the sensor pads and the ...

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STMPE1208S The STMPE1208S maintains 2 parameters for each touch channels: TVR and calibrated impedance. calibrated impedance is an internal reference of which, if the currently measured impedance exceeds the calibrated impedance by a magnitude of TVR considered a ...

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Capacitive sensors Figure 11. 3-stage data filtering system Touch/No-touch from calibration unit Integration and filtering unit Touch is sampled across a programmable period of time. The output of the integration stage would be a "strength" (in strength register) that indicates ...

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STMPE1208S 5.3.4 Interrupt system 2 interrupt pins are available in STMPE1208S for different application needs. – G_INT asserts when there are any unmasked interrupt events – T_INT asserts when there are any touch events Figure 12. Interrupt system EINT enable ...

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Register map and function description 6 Register map and function description This section lists and describes the registers of the STMPE1208S device, starting with a register map and then detailed descriptions of register types. Table 7. Register summary map table ...

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STMPE1208S Table 7. Register summary map table (continued) Address 0x2A CAL_INTERVAL 0x2B EXT_INT_EN 0x2C EXT_INT_POL 0x2D FILTER_PERIOD 0x2E FILTER_TRES − 0x50 0x5B STRENGHT − 0x5C 0x67 CAL_IMP − 0x68 0x73 IMP 0x74 STA 0x75 TOUCH_BYTE_L 0x76 TOUCH_BYTE_H 0x77 INT_PENDING 0x78 ...

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Register map and function description FEATURE_SEL RESERVED Address: 0x00 Type: R/W Reset: 0x04 Description: The feature selection register is used to select the AFS mode and filter enable [7:4] RESERVED [3] AFS3: write '1' to enable AFS ...

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STMPE1208S EVR Address: 0x0D Type: R/W Reset: 0x04 Description: EVR is used to detect "Non-Touch" condition. Each step of EVR is equivalent to a capacitance of 60 fF. Recommended value to EVR is 2-6 (EVR must ...

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Register map and function description STRENGTH_THRES Address: 0x10 - 0x1B Type: R/W Reset: 0x01 Description: Setting threshold to be used in AFS mode to determin a valid touch. [7:0] Strength_threshold INTEGRATION_TIME Address: 0x1C Type: ...

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STMPE1208S GPIO_STA_L IO-7 IO-6 IO-5 Address: 0x1E Type: R/W Reset: 0x00 Description DIO is set to function as GPIO (GPIO_CFG register) and output (GPIO_DIR register), the bits in this register would determine the output value ...

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Register map and function description GPIO_DIR_L IO-7 IO-6 IO-5 Address: 0x22 Type: R/W Reset: 0x00 Description: Writing '1' in this register sets the corresponding GPIO as input. Writing '0' in this register sets the corresponding GPIO as ...

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STMPE1208S [2] HDC_U: Unconditional host driven calibration. Executes an unconditional calibration. This is valid only if "Hold C" bit is set, and device in Active mode. Reads '0' when calibration is completed. [1] HDC_C: Conditional host driven calibration. Executes a ...

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Register map and function description CTRL_2 RESERVED Address: 0x25 Type: R/W Reset: 0x00 Description: Control register. [7:4] Reserved [3] REGD: '0' to enable internal regulator (default) '1' to disable [2] SCD: Sensor clock disable. Write '1' to ...

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STMPE1208S INT_CLR EOC EINT Address: 0x27 Type: Reset: 0x00 Description: If the corresponding bit in the INT_PENDING register is set, system software must write '1' to this register to clear the bits in INT_PENDING register. [7] ...

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Register map and function description BEEP_FREQUENCY Address: 0x29 Type: R/W Reset: 0x00 Description: Beep frequency in kHz = system clock/(beep frequency [7:0]*2)+2) [7:0] Beep_frequency: Min Freq = 200 kHz/512 = 390 Hz Max Freq = 1.6 MHz/2 ...

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STMPE1208S EXT_INT_POL IO-7 IO-6 IO-5 Address: 0x2B Type: R/W Reset: 0x00 Description: Polarity of GPIO interrupt ‘0’ positive edge on external interrupt input sets GINT. ‘1’ negative edge on external interrupt input sets GINT. Register map and ...

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Register map and function description FILTER_PERIOD Address: 0x2D Type: R/W Reset: 0x00 Description: Filter period. [7:0] Filter_count: Additional filter to stabilize touch output in AFS mode. AFS touch output is monitored for filter period [7:0] times every ...

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STMPE1208S CALIBRATED_IMPEDANCE 7 6 Address: 0x5C - 0x67 Type: R Reset: 0x00 Description: Calibrated reference impedance = 128 - CAL.Impedance[7:0]. [7:0] CAL_IMPEDANCE: Calibrated reference impedance. IMPEDANCE 7 6 Address: 0x68 - 0x73 Type: R Reset: 0x00 Description: Impedance is the ...

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Register map and function description TOUCH_BYTE_L 7 6 CH7 CH6 Address: 0x75 Type: R Reset: 0x00 Description Reads the touch status of channel n (n=0-7). If the key is touched (Impedance > calibrated impedance + TVR), the corresponding ...

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STMPE1208S INT_PENDING 7 6 RESERVED Address: 0x77 Type: R Reset: 0x00 Description: This register reflects the status of various possible interrupt sources. Upon the occurrence of an event, the corresponding bit in this register will be set to '1' by ...

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Command registers 7 Command registers The command registers do not have a data field. The device carries out a predetermined operation upon receiving a write access to these address offset. However, a dummy data- phase is used to complete the ...

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STMPE1208S Figure 13. Software interface (G_INT based) Initialization GPIO configuration, direction and output Calibration interval ETC wait Feature select EVR setting EVR setting Integration time TVR setting Integration treshold setting Control 1, control 2 Wait for interrupt Interrupt service routine ...

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Command registers Figure 14. Software interface (T_INT based) 38/47 Initialization GPIO configuration, direction and output Calibration interval ETC wait Feature select EVR setting EVR setting Integration time TVR setting Integration treshold setting Control 1, control 2 Wait for interrupt Interrupt ...

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STMPE1208S 8 Maximum rating Stressing the device above the rating listed in the “Absolute maximum ratings” table may cause permanent damage to the device. These are stress ratings only, and operation of the device at these or any other conditions ...

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Electrical specifications 9 Electrical specifications Table 11. DC electrical characteristics (-40 Symbol I GPIO driving current out I Active current active I Idle current idle I Sleep current sleep V Digital input low IL V Digital input high IH V ...

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STMPE1208S 10 Package mechanical data In order to meet environmental requirements, ST offers these devices in different grades of ® ECOPACK packages, depending on their level of environmental compliance. ECOPACK specifications, grade definitions and product status are available at: www.st.com. ...

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Package mechanical data Figure 15. QFN40 ( mm) package outline 42/47 Doc ID 14438 Rev 5 STMPE1208S 8072802_A ...

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STMPE1208S Figure 16. QFN40 recommended footprint without ground pad VIA Figure 17. QFN40 recommended footprint with ground pad VIA 0.68 1.27 0.30 1.27 0.68 Via Doc ID 14438 Rev 5 Package mechanical data 43/47 ...

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Package mechanical data Figure 18. QFN40 tape information 44/47 Doc ID 14438 Rev 5 STMPE1208S ...

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STMPE1208S Figure 19. Reel information Doc ID 14438 Rev 5 Package mechanical data 45/47 ...

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Revision history 11 Revision history Table 13. Document revision history Date 14-Feb-2008 04-Jun-2008 18-Jul-2008 26-May-2008 18-Dec-2009 46/47 Revision 1 Initial release. Modified title in cover page and ETC_WAIT register description. Updated: Table 5: Operation modes on page 12 2 Added ...

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... STMPE1208S Information in this document is provided solely in connection with ST products. STMicroelectronics NV and its subsidiaries (“ST”) reserve the right to make changes, corrections, modifications or improvements, to this document, and the products and services described herein at any time, without notice. All ST products are sold pursuant to ST’s terms and conditions of sale. ...