STMPE321QTR STMicroelectronics, STMPE321QTR Datasheet
STMPE321QTR
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STMPE321QTR Summary of contents
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... Mobile phones and smartphones ■ Portable media players ■ Game consoles Table 1. Device summary Order code STMPE321QTR August 2009 3-channel capacitive touchkey controller Description The STMPE321 is a 3-channel capacitive touchkey controller. Capacitance measurement is A µ implemented in fully optimized hardware. All 3 I/Os can be configured via an I function as either capacitive touchkey GPIOs (general purpose I/O) ...
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Contents Contents 1 STMPE321 functional overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 1.1 ...
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STMPE321 1 STMPE321 functional overview The STMPE321 consists of the following blocks: ● GPIO controller ● Impedance sensor ● Touchkey controller 2 ● interface 1.1 STMPE321 block diagram Figure 1. Functional block diagram RST SCLK SDA INT IO ...
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STMPE321 functional overview 1.2 Pin assignment and function Figure 2. QFN12 pin assignment (top view) Table 2. Pin assignment and function Pin number 4/40 Pin name GPIO_2 / ...
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STMPE321 1.3 STMPE321 typical application The STMPE321 is capable of supporting capacitive sensors channels. Figure 3. Typical application diagram STMPE321 functional overview Doc ID 15791 Rev 3 5/40 ...
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Capacitance compensation 2 Capacitance compensation The STMPE321 is capable to measuring up to 5.1pF in capacitance difference between the reference point (Zref) and the individual channels. In the case where PCB connection between the sensor pads and the device is ...
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STMPE321 2.1 Calibration algorithm The STMPE321 maintains 2 parameters for each touch channel: TVR and CALIBRATED IMPEDANCE. CALIBRATED IMPEDANCE is an internal reference which, if the currently measured IMPEDANCE exceeds the CALIBRATED IMPEDANCE by a magnitude of TVR, is considered ...
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Capacitance compensation 2.1.1 Noise filtering When the STMPE321 is operating in the vicinity of highly emissive circuits (DC-DC converters, PWM controllers/drives etc.), the sensor inputs can be affected by high- frequency noise. In this situation, the time-integrating function can be ...
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STMPE321 2.2 Power management The STMPE321 operates in 3 states, as described below: Figure 5. STMPE321 operating states On RESET, the STMPE321 enters the ACTIVE state immediately. Upon a fixed period of inactivity, the device enters a SLEEP state. Any ...
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I2C interface interface The following features are supported by the I 2 ● slave device ● Compliance with Philips I ● Standard (up to 100 kbps) and fast (up to 400 kbps) modes. ● ...
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STMPE321 Table 4. Operation modes Mode Read Write Figure 6. Read and write modes (random and sequential) One byte Read More than one byte Read One byte Write More than one byte Read Byte Programming sequence Start, Device address, R/W ...
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Register map and function description 4 Register map and function description This section lists and describes the registers in the STMPE321 device starting with a register map, and then provides detailed descriptions of the register types. Table 5. Register summary ...
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STMPE321 Table 5. Register summary map table (continued) Address Register name STRENGTH_THRES 0x50-0x52 [0-2] 0x60 - STRENGTH [0-2] 0x62 0x70 - CAL_IMPEDANCE [0-2] 0x72 0x80 - IMPEDANCE [0-2] 0x82 0x92 INT_PENDING Register map and function description Bit Type Reset value ...
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System and identification registers 5 System and identification registers Table 6. System and identification registers map Address Register name 0x00 CHIP_ID_0 0x01 CHIP_ID_1 0x02 ID_VER 0x03 SYS_CFG_1 0x04 SYS_CFG_2 CHIP_ID_x Address: 0x00, 0x01 Type: R Reset: 0x03, 0x21 Description: 16(8+8)-bit ...
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STMPE321 ID_VER Address: 0x02 Type: R Reset: 0x03 Description: 8-bit revision number SYS_CFG_1 RESERVED Address: 0x03 Type: R/W Reset: 0x00 Description: The reset control register enables the reset of the device [7:4] RESERVED [3] SLEEP: Write ‘1’ ...
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System and identification registers SYS_CFG_2 SENSOR SENSOR SENSOR CLOCK 2 CLOCK 1 CLOCK 0 Address: 0x04 Type: R/W Reset: 0xEF Description: This register enables the switching off of the clock supply [7:5] SENSOR CLOCK: See description in ...
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STMPE321 6 Interrupt controller module Figure 7. Interrupt controller module block diagram INT pending INT MASK GPIO interrupt status GPIO interrupt enable Interrupt status Interrupt enable AND Doc ID 15791 Rev 3 Interrupt controller module INT AND 17/40 ...
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Interrupt controller module INT_CTRL 7 6 RESERVED Address: 0x08 Type: R/W Reset: 0x01 Description: This register is used to enable control of the polarity, edge/level and enabling of the interrupt system device. [7:3] RESERVED [2] POLARITY: '0' for active low ...
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STMPE321 INT_EN GPIO RESERVED Address: 0x09 Type: R/W Reset: 0x01 Description: This register is used to enable the interruption from a system related interrupt source to the host. Writing ‘1’ in this register enables the corresponding interrupt ...
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Interrupt controller module INT_STA GPIO RESERVED Address: 0x0A Type: R/W Reset: 0x09 Description: This register is used to enable the interruption from a system related interrupt source to the host. Regardless of whether or not the IESYSIOR ...
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STMPE321 GPIO_INT_EN RESERVED Address: 0x0B, 0x0C Type: R/W Reset: 0x00 Description: The GPIO interrupt enable register is used to enable the interruption from a particular GPIO interrupt source to the host. The IEg[2:0] bits and the interrupt ...
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GPIO controller 7 GPIO controller A total of 3 GPIOs are available in the STMPE321. The GPIO controller contains the registers that allow the host system to configure each of the pins into either a GPIO or Touch input. Unused ...
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STMPE321 The function of each bit is shown Table 9. GPIO control bits function Register name GPIO monitor pin state GPIO set pin state GPIO set pin direction GPIO function inTable 9: Function Reading this bit yields the current state ...
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Capacitive touch module registers 8 Capacitive touch module registers Table 10. TOUCH_FIFO summary table TOUCH_FIFO Address: 0x19, 0x18 Type: R Reset: 0x00 Description: TOUCH_FIFO is the access port for the internal 4-level FIFO used ...
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STMPE321 FEATURE_SELECT RESERVED Address: 0x20 Type: R/W Reset: 0x04 Description: Controls AFS (advanced filtering system and second level filtering feature) [7:3] RESERVED [2:1] AFS[1:0]: “00’: reserved “01’ AFS mode 1 (only 1 strongest key) ‘10’: AFS mode ...
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Capacitive touch module registers CAL_INTERVAL Address: 0x22 Type: R/W Reset: 0x30 Description: Calibration interval [7:0] CALIBRATION INTERVAL: Interval between calibration = calibration interval [7:0] * sensor clock period * 50 Range INTEGRATION ...
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STMPE321 CTRL RESERVED Address: 0x25 Type: R/W Reset: 0x00 Description: Control [7:4] RESERVED [3] F2A: Write '1' to force device to remain in ACTIVE state at all times [2] HDC_U: Write '1' to perform unconditional host driven ...
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Capacitive touch module registers INT_MASK RESERVED Address: 0x26 Type: R/W Reset: 0x08 Description: Writing '1' to this register disables the corresponding interrupt source. [7:4] RESERVED [3] EOC: End of calibration This interrupt occurs on both automatic and ...
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STMPE321 FILTER_PERIOD Address: 0x28 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 Count [7:0] times every integration time. For each ...
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Capacitive touch module registers TVR RESERVED Address: 0x30 - 0x32 Type: R/W Reset: 0x08 Description: Touch variance setting [7] RESERVED [6:0] TVR: Setting TVR between 0-99 A high TVR value decreases sensitivity of the sensor, but increases ...
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STMPE321 STRENGTH 7 6 Address: 0x60 - 0x62 Type: R Reset: 0x00 Description: The number of times a sensed capacitance exceeds the calibrated reference impedance [7:0] STRENGTH: Read-only field Counts the number of times a sensed impedance exceeds calibrated reference ...
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Capacitive touch module registers CALIBRATED_IMPEDANCE 7 6 Address: 0x70 - 0x72 Type: R Reset: 0x00 Description: Calibrated impedance is a reference value maintained by the device. [7:0] CALIBRATED IMPEDANCE: Calibrated reference impedance IMPEDANCE 7 6 Address: 0x80 - 0x82 Type: ...
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STMPE321 9 Maximum ratings 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 10 Electrical specifications Table 12. DC electrical characteristics (- °C unless otherwise stated) Symbol V Core supply voltage CC I HIBERNATE current hibernate I SLEEP current sleep I ACTIVE current active V Input voltage low state ...
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STMPE321 11 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 Table 14. Mechanical data for QFN12 (2.2 x 1.5 x 0.5 mm) - 0.40 mm pitch Symbol Figure 9. Footprint recommendations for QFN12 (2.2 x 1.5 x 0.5 mm) - ...
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STMPE321 Figure 10. Carrier tape for QFN12 (2.2 x 1.5 x 0.5 mm) - 0.40 mm pitch Doc ID 15791 Rev 3 Package mechanical data 785978-J 37/40 ...
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Package mechanical data Figure 11. Reel information for QFN12 (2.2 x 1.5 x 0.5 mm) - 0.40 mm pitch 1. Drawing not to scale. 2. Dimensions are in millimeters 38/40 Doc ID 15791 Rev 3 STMPE321 7875978 ...
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STMPE321 12 Revision history Table 15. Document revision history Date 19-Jun-2009 29-Jul-2009 12-Aug-2009 Revision 1 Initial release. Deleted “internal regulator” from the Features section. 2 Modified: Figure 1, Chapter Chapter 5, Chapter 1.3 3 Modified: Figure 4. Doc ID 15791 ...
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