STM8T141 STMicroelectronics, STM8T141 Datasheet
STM8T141
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STM8T141 Summary of contents
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... Single-channel capacitive sensor for touch (narrow) Table 1. Device summary Feature Operating supply voltage Supported interface Operating temperature Packages Doc ID 15699 Rev 7 STM8T141 SO8 UFDFPN8 ( mm) STM8T141 2 5.5 V Single key state output –40° to +85 °C 8-pin SO 8-pin UFDFPN www.st.com 1/50 1 ...
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... Detection threshold . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 7.4 Power modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 7.4.1 7.4.2 7.4.3 7.4.4 7.5 Charge transfer frequency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 2/50 ECF principle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 Reference freeze timeout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 Debounce filter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 Active . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 Toggle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 3-second latch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 30-second latch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 Normal Power mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 Low Power mode with Zoom . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 Extreme Low Power mode with Zoom . . . . . . . . . . . . . . . . . . . . . . . . . . 24 Extreme Low Power mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 Doc ID 15699 Rev 7 STM8T141 ...
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... STM8T141 7.6 Sampling period . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 8 Design guidelines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 8.1 Shield function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 8.1.1 8.2 Sensitivity adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 8.2.1 8.2.2 8.3 Influence of power supply variation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 9 Electrical characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 9.1 Parameter conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 9.1.1 9.1.2 9.1.3 9.1.4 9.2 Absolute maximum ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 9.3 Operating conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 9.3.1 9.3.2 9.3.3 9.4 Regulator and reference voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 9.5 Capacitive sensing characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 9.6 EMC characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 9.6.1 9.6.2 9.6.3 9.6.4 9.6.5 9.6.6 10 Package characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38 10.1 Package mechanical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38 10.1.1 10.1.2 10.2 Package thermal characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41 10 ...
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... Contents 11 Ordering information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42 11.1 STM8T141 ordering information scheme . . . . . . . . . . . . . . . . . . . . . . . . . 42 11.2 Orderable favorite device lists . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43 11.3 In-factory option byte programming service . . . . . . . . . . . . . . . . . . . . . . . 43 12 STM8T141 development tools . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45 13 Revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48 4/50 Doc ID 15699 Rev 7 STM8T141 ...
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... STM8T141 List of tables Table 1. Device summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Table 2. STM8T141 pin descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 Table 3. Explanation of ECF example Table 4. Explanation of ECF example Table 5. Option bytes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 Table 6. Option byte description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 Table 7. Detection thresholds . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 Table 8. Low power period according to selected power mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 Table 9. Voltage characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 Table 10 ...
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... Figure 23. Sigma variation across V Figure 24. SO8-lead plastic small outline - package outline . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38 Figure 25. UFDFPN8-lead ultra thin fine pitch dual flat package (MLP) package outline . . . . . . . . . . 40 Figure 26. STM8T141 ordering information scheme . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42 Figure 27. STM8T141-EVAL evaluation kit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45 Figure 28. STM8T141 blank module box . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46 Figure 29. STM8T141-EVAL programming tool 6/50 SHIELD ...
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... The STM8T141 is a ProxSense™ single-channel, fully integrated, charge-transfer, capacitive sensor that is designed to replace conventional electromechanical switches in cost-sensitive applications. The STM8T141 is offered in 8-pin packages and is ideally suited for 1-button applications. It can be configured either in touch or proximity sensing mode for wake-up or backlighting on actuation. ...
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... Block diagram 2 Block diagram Figure 1. STM8T141 block diagram C X ProxSense engine C S SHLDIN RC oscillator The 500-kHz RC oscillator is an internal fixed frequency oscillator used to supply the clock to the MCU system engine. Power-On-Reset (POR) The POR generates a reset signal depending on the power supply level and the clock pulses received from the RC oscillator ...
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... STM8T141 3 Pin descriptions Figure 2. S08 pinout Figure 3. UFDFPN8 pinout Table 2. STM8T141 pin descriptions Pin no. SO8 UFDFPN8 input pin, OD: open drain, PP: output push-pull pin, S: supply pin and SNS: capacitive sensing pin. 2. Use COG or NPO capacitor type the active shield is unused, please connect this pin Requires a low ESR, 1µ ...
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... STM8T touch sensing controller. Connecting the serial resistor (R C pin improves ESD immunity even more. X 10/50 Sensing electrode C X Lower capacitance Higher capacitance pin composed of a serial resistor R X Doc ID 15699 Rev 7 STM8T141 Figure 4 (see Figure 5). The sensing the X ...
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... STM8T141 Figure 5. STM8T measuring circuitry STM8T141 must be placed as close as possible to the STM8T device. X The principle of charge transfer is to charge the electrode capacitance (C power supply. When external sampling capacitance, referred until the voltage across the sampling capacitor C voltage (V ) ...
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... STM8T processing 5 STM8T processing The STM8T141 device is designed to ensure reliable operation whatever the environment and operating conditions. To achieve this high level of robustness, dedicated processing have been implemented: ● Signal and reference calculation ● Determining touch/proximity ● Self-calibration ● Environmental compensation filter ● ...
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... The capacitive sensing channel reference value increases or decreases according to environmental conditions such as temperature, power supply, moisture, and surrounding conductive objects. The STM8T141 includes a built-in digital infinite impulse response (IIR) filter capable of tracking slow changes in the environment called the Environment Compensation Filter (ECF). This is a first order digital low pass filter with a gain of one. The filter makes the reference follow slow changes of the signal while fast changes are recognized as a touch or proximity ...
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... Zone 2 An object (finger) is The object is still under detected. The detection but, the environment continues environment is not to change. changing anymore. Detection Halt Frozen Changing Doc ID 15699 Rev 7 STM8T141 t Zone 4 ai17429 Zone 3 Zone 4 The object exits from detection. No detection Active Adapting Stable ...
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... STM8T141 5.3.2 Reference freeze timeout To prevent an object under detection from influencing the reference value, the ECF is halted as soon as a detection happens. Consequently, the reference is frozen. In order to be able to recover from a sudden environment change, the reference freeze ends after a maximum programmable delay called the “reference freeze timeout” (t When a detection lasts longer than the t moves toward the detection signal ...
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... Debouncing is applied to acquisition samples to filter undesired abrupt changes. The number of consecutive detection debounce count (DDC) and end of detection debounce count (EDDC) needed to identify a proximity/touch detection are defined in Section 9.5: Capacitive sensing characteristics on page 16/50 33. Doc ID 15699 Rev 7 STM8T141 ...
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... STM8T141 6 Typical application diagram Figure 10. Typical application shematic 1. If the active shield is not used, The SHLDIN pin must be grounded, SHLDOUT should be left unconnected, and can be removed. 2. Use COG or NPO or higher grade capacitor. The smaller the value of the R consumption. Pin TOUT/POUT can directly drive a HV FET (as shown in any load ...
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... These options can be used in their default (unconfigured) state or set for specific applications. For large orders, preconfigured devices are available (please refer to Section 11: Ordering The STM8T141 can be configured to act as a touch or proximity detection device. A number of other options are also user programmable, including: ● ...
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... STM8T141 Table 6. Option byte description Option byte no. Bits [7:3]: Reserved Bit 2: Sampling period (t 0: Conversion period is 20 ms 1: Conversion period OPT1 Bit 1: Charge transfer frequency (f 0: 125 kHz 1: 250 kHz Bit 0: Reserved Bits [7:6]: Power mode 00: Low Power mode with Zoom ...
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... Device operation 7.2 TOUT/POUT output mode Four output modes are available on the STM8T141: ● Active mode ● Toggle mode ● 3-second Latch mode ● 30-second Latch mode For each output operation described, touch or proximity detection can be used. Upon the detection of either of these actions, the TOUT/POUT pin will latch high, otherwise the TOUT/POUT pin stays low ...
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... STM8T141 7.2.2 Toggle Upon the detection of an actuation, the TOUT/POUT pin will toggle between high and low. Thus if TOUT/POUT is low, an actuation will change it to high, and also if TOUT/POUT is high, an actuation will change it to low. Figure 13. Toggle mode output operation 7.2.3 3-second latch Upon the detection of an actuation the TOUT/POUT pin will latch high for 3 seconds minimum ...
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... Th Proximity for battery-powered applications. Proximity with good ground. Contact through acrylic glass and no ground. Contact through thin acrylic glass with battery application. Contact through thin dielectric with good ground. Doc ID 15699 Rev 7 STM8T141 ) at which the touch or Th Description ...
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... STM8T141 7.4 Power modes The STM8T141 device offers four power modes. The low power modes are specifically designed for battery applications: ● Normal Power mode ● Low Power mode with Zoom ● Extreme Low Power mode with Zoom ● Extreme Low Power mode ...
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... Device operation 7.4.2 Low Power mode with Zoom With the STM8T141 in Low Power mode with Zoom, burst cycles occur every 5th t period (or 20% of the Normal Power mode). Once activity is detected, the STM8T141 device wakes up from Low Power mode with Zoom to Normal Power mode with charge cycles occurring every t return to Low Power mode after an end of low power period (t proximity detection conditions are detected ...
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... STM8T141 7.4.4 Extreme Low Power mode With the STM8T141 in Extreme Low Power mode, burst cycles only occur every 17th t period (or 5.88% of the Normal Power mode), thus adding 16 extra delays of SAMPLING t between charge cycles to conserve power. SAMPLING This reduces the amount of burst cycles in Extreme Low Power mode even more than Low ...
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... Design guidelines 8 Design guidelines 8.1 Shield function The STM8T141 offers a built-in shielding function. This function provides the following advantages for designing the end-application: ● Sensing electrode separated from sealed electronics. ● Sensing wire shielded from unwanted environmental interferences. ● Enhanced proximity detection when used with battery (DC) applications. ...
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... STM8T141 Figure 20. Connecting the shield (coaxial cable implementation) Coaxial cable Plastic jacket Metal shield 8.2 Sensitivity adjustment Several factors impact device sensitivity: ● The sensing electrode material and size ● The touch panel material and thickness ● The board layout and in particular the sensing signal tracks ● ...
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... The parameter Ϭ is the power supply rejection ratio. For stability reasons advised to limit BC to less than half the detection threshold less than 2.9 V, special care should be taken of the supply quality. An external DD voltage regulator may be necessary. 28/50 Equation 1. Doc ID 15699 Rev 7 STM8T141 ...
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... STM8T141 9 Electrical characteristics 9.1 Parameter conditions Unless otherwise specified, all voltages are in reference to V 9.1.1 Minimum and maximum values Unless otherwise specified, the minimum and maximum values are guaranteed in the worst conditions of ambient temperature and supply voltage by tests in production on 100% of the devices with an ambient temperature at T temperature range) ...
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... SS Ratings Parameter Shield feature not used Shield feature used Doc ID 15699 Rev 7 Maximum value 5.5 Maximum value ( Value 65 to +150 90 Condition Min. Max. 2.0 4.5 - -40 0 (1) 1 STM8T141 Unit V Unit mA Unit °C °C Unit 5.5 V 5.5 85 °C 1 V/s ...
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... STM8T141 9.3.2 Average current consumption Test conditions: T Table 13. Average current consumption without shield Symbol Normal Power mode Low Power I DD Extreme Low Power mode 1. Data based on characterization results, not tested in production. Note: Consumption does not depend on either detection threshold or acquisition rate. Figure 22. I ...
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... Typ. Max 1200 1600 = 4 mA 540 750 = 2 mA 250 450 = 4 mA 650 1000 = 2 mA 320 500 = 2 mA 400 500 = 1 mA 300 500 = –2 mA 4.7 = –4 mA 4.4 = –8 mA 3.9 = –2 mA 3.0 = –4 mA 2.7 = –2 mA 2.5 = -100 µA 1 Min. Typ. Max 2.1 0.68 STM8T141 Unit Unit µF V ...
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... STM8T141 9.5 Capacitive sensing characteristics . Table 16. General capacitive sensing characteristics Symbol Charge-transfer frequency at 125-kHz setting f TRANSFER Charge-transfer frequency at 250-kHz setting Scanning period at 10-ms setting t SAMPLING Scanning period at 20-ms setting Low Power t LP Extreme Low Power Time before switching back to Low t ELP Power mode 15 s reference freeze timeout ...
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... X R Shield pull-up resistance SHIELD 1. For more information about capacitors, please refer to Application note: AN2966. 34/50 DD (1) t SAMPLING Mode Min 510 Parameter (1) Doc ID 15699 Rev 7 STM8T141 = SAMPLING Max. Min. Max 100 100 60 200 250 60 500 850 1020 1700 Min ...
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... STM8T141 9.6 EMC characteristics Susceptibility and emission tests are performed on a sample basis during product characterization. Both the sample and its applicative hardware environment dedicated specific EMC board defined in the IEC61967-1 standard. 9.6.1 Functional EMS (electromagnetic susceptibility) While running in the above described environment the product is stressed by two electromagnetic events until a failure occurs. ● ...
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... MHz to 130 MHz Complies with SAE 130 MHz to 1 GHz J1752/3, Finger on touch electrode Ratings Conditions +25°C, conforming JESD22-A114 +25°C, conforming JESD22-C101 Doc ID 15699 Rev 7 STM8T141 RC Monitored OSC = (1) 500 kHz -4 -9 dBµ dBµ ...
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... STM8T141 9.6.6 Static latchup Two complementary static tests are required on 10 parts to assess the latchup performance. ● A supply overvoltage (applied to each power supply pin) and ● A current injection (applied to each input, output and configurable I/O pin) are performed on each sample. This test conforms to the EIA/JESD 78 IC latchup standard. For more details, refer to application note AN1181 ...
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... ECOPACK® trademark. 10.1 Package mechanical data 10.1.1 SO8 package mechanical data Figure 24. SO8-lead plastic small outline - package outline A2 38/50 A ccc Doc ID 15699 Rev 7 STM8T141 h x 45˚ c 0.25 mm GAUGE PLANE SO-A ...
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... STM8T141 Table 23. 8-lead plastic small outline - package mechanical data Symbol ccc ( ( Values in inches are rounded to 4 decimal digits 2. Dimension D does not include mold flash, protrusions or gate burrs. Mold flash, protrusions or gate burrs shall not exceed 0.15mm in total (both side). ...
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... Doc ID 15699 Rev 7 STM8T141 UFDFPN-01 (1) inches Min Typ Max 0.0177 0.0217 0.0236 0.0000 0.0008 0.0020 0.0079 0.0098 0.0118 0.0748 0.0787 0.0827 0.0591 ...
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... STM8T141 10.2 Package thermal characteristics The maximum chip junction temperature (T Table 12: Operating characteristics on page The maximum chip-junction temperature, T using the following equation: Where: is the maximum ambient temperature in C ● T Amax is the package junction-to-ambient thermal resistance in C/W ● JA ● the sum of P Dmax ● ...
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... See Table 26: Orderable favorite device lists programming service” 2. The STM8T141 OTP devices are available for production and development. These parts are blank devices with unconfigured option bytes (all option bits are set to ‘0’). For more information, please refer to ...
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... Customers have to fill out the option list (see below) and send it back to STMicroelectronics. Customers are then informed by STMicroelectronics about the ordering part number corresponding to the customer configuration. The XXXY parameter of the final ordering part number (e.g. STM8T141AMXXXY) depends on the device configuration and is assigned by STMicroelectronics. (1) ...
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... Ordering information STM8T141 programming service option list Customer name: Address: Contact name: Phone number: Select the package type (tick one box) STM8T141AM6 - S08 Sampling period (see Section 7.6: Sampling † sampling period † sampling period (1) Charge transfer frequency (see † 125 kHz (1) † ...
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... STM8T141 evaluation kit The STM8T141-EVAL is an evaluation kit which introduces developers to the STM8T141. It contains an STM8T141 evaluation board, plus a set of preconfigured plug-in modules which allow the STM8T141 device performances to be evaluated in either touch or proximity detection. Figure 27. STM8T141-EVAL evaluation kit STM8T141 development tools ...
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... STM8T141 development tools STM8T141 “blank” modules An additional box of 10 STM8T141 “blank” modules (STM8T141AM-MOD) can be ordered separately, where the device option bytes are left unprogrammed (see Figure 28. STM8T141 blank module box 1. The above figure is not binding. 46/50 Doc ID 15699 Rev 7 STM8T141 Figure 28) ...
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... Ordering information Part number STM8T141-EVAL STM8T-MOD ST-TSLINK STM8T14X-SB 1. The ST-TSLINK dongle and the STM8T14X-SB socket board are not part of the STM8T141-EVAL evaluation kit, and consequently must be ordered separately. Programming dongle (ST-TSLINK) Order codes STM8T141-EVAL STM8T141 evaluation kit Box containing 10 blank modules based on ...
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... Table 17: Response times on page Updated Section 11: Ordering Section 11.2: Orderable favorite device 4 option byte programming; added option list. Added Section 12: STM8T141 development tools Lower operating supply voltage changed from 2 2.0 V. The following tables were impacted: Operating characteristics, without shield, Table 16: General capacitive sensing ...
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... Figure 26: STM8T141 ordering information footnote 2. Programming tool: replaced STM8T141-SB with STM8T14X-SB. Figure 29: STM8T141-EVAL programming 7 STM8T141-SB with STM8T14X-SB. Table 27: Ordering information: replaced STM8T1X1-EVAL and STM8T141-SB with STM8T141-EVAL and STM8T14X-SB respectively. Doc ID 15699 Rev 7 Revision history Changes 7.2.2, Section 7.2.3, and Section latch: removed some text concerning the threshold ...
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... Australia - Belgium - Brazil - Canada - China - Czech Republic - Finland - France - Germany - Hong Kong - India - Israel - Italy - Japan - Malaysia - Malta - Morocco - Philippines - Singapore - Spain - Sweden - Switzerland - United Kingdom - United States of America 50/50 Please Read Carefully: © 2011 STMicroelectronics - All rights reserved STMicroelectronics group of companies www.st.com Doc ID 15699 Rev 7 STM8T141 ...