AT42QT1012-MAH Atmel, AT42QT1012-MAH Datasheet
AT42QT1012-MAH
Specifications of AT42QT1012-MAH
Related parts for AT42QT1012-MAH
AT42QT1012-MAH Summary of contents
Page 1
... Power: – 1.8V ~ 5.5V; 32 µA at 1.8V • Package: – 6-pin SOT23 mm) RoHS compliant – 8-pin UDFN/USON ( mm) RoHS compliant • Signal processing: – Self-calibration, auto drift compensation, noise filtering One-channel Toggle-mode Touch Sensor IC with Power Management Functions AT42QT1012 9543D–AT42–08/10 ...
Page 2
... Pinout and Schematic 1.1 Pinout Configurations 1.1.1 6-pin SOT23-6 1.1.2 8-pin UDFN/USON AT42QT1012 2 OUT 1 6 TIME VSS 2 5 VDD SNSK 3 4 SNS Pin SNS SNSK 1 N VDD QT1012 N TIME 4 5 VSS OUT 9543D–AT42–08/10 ...
Page 3
... O Output only, push-pull Basic Circuit Configuration (active high output, toggle on/off, no auto switch off) Cby RS 3 SNSK CS 4 SNS Rm AT42QT1012 If Unused, Connect Cs + key Cs for details. Section 3.11 on page 11 for I/O Input and output P Ground or power Note: bypass capacitor to be tightly VDD ...
Page 4
... Sample resistor (Rs) – see • Voltage levels – see • Output polarity selection resistor (Rop) – see • Rm resistor – see • Bypass capacitor (Cby) – see AT42QT1012 4 Basic Circuit Configuration (active high output, toggle on/off, no auto switch off) VDD ...
Page 5
... Overview of the AT42QT1012 2.1 Introduction The AT42QT1012 (QT1012 single key device featuring a touch on/touch off (toggle) output with a programmable auto switch-off capability. The QT1012 is a digital burst mode charge-transfer (QT controls. It includes all hardware and signal processing functions necessary to provide stable sensing under a wide variety of changing conditions; only low cost, noncritical components are required for operation ...
Page 6
... Metal areas near the electrode will reduce the field strength and increase Cx loading and should be avoided, if possible. Keep ground away from the electrodes and traces. 2.4.3 Decreasing Sensitivity In some cases the QT1012 may be too sensitive. In this case gain can be easily lowered further by decreasing Cs. AT42QT1012 6 Sense Connections SENSE ELECTRODE RS ...
Page 7
... Figure 3-2 on page 7). Low Power Mode: Touch Confirmed (Output in Off Condition) ~80 ms Sleep SNSK OUT Low Power Mode: Touch Denied (Output in Off Condition) ~80 ms Sleep Sleep AT42QT1012 Fast detect integrator Sleep Sleep Fast detect integrator Sleep Sleep 7 ...
Page 8
... Once an object is sensed, the drift compensation mechanism ceases since the signal is legitimately high, and therefore should not cause the reference level to change. AT42QT1012 8 (Figure 3-3 on page 9) is performed by making the reference level track the ...
Page 9
... The QT1012 modulates its internal oscillator by ±7.5 percent during the measurement burst. This spreads the generated noise over a wider band, reducing emission levels. This also reduces susceptibility since there is no longer a single fundamental burst frequency. 9543D–AT42–08/10 Drift Compensation S ignal Threshold R eference Output AT42QT1012 H ysteresis 9 ...
Page 10
... Note that some devices such as Digital Transistors have an internal biasing network that will naturally pull the OUT pin to its inactive state. If these are being used then the resistor Rop is not required (see Figure 3-5. AT42QT1012 10 Figure 3-4 Output Polarity (6-pin SOT23) ...
Page 11
... Cs. 9543D–AT42–08/10 (Section 3.11.2) (Section 3.11.3 on page (Section 3.11.5 on page Section 3.11.2. and Table 3-3 on page 12. This provides nominal values of 15 minutes, 60 Figure 3-6 on page 12, Table 3-2 on page 12 Section 3.11.5 on page 17). AT42QT1012 12) 17) and Table 3-3 on page 12 ...
Page 12
... If a user-programmed delay is required network (resistor and capacitor) can be used to set the auto-off delay (see dependent on the RC time constant (Rt x Ct), the output polarity and the supply voltage. Section 3.11.4 on page 13 delay times ranging from minutes to hours. AT42QT1012 12 Predefined Delay SENSE ELECTRODE ...
Page 13
... Delay K -------------------------- - k nF, Delay is in seconds. K values are obtained from page 14. Programmable Auto-off Delay (Example Vss (delay multiplier = 1), Vdd = 3.5V Auto Off Delay (Seconds Figure 3-8 on page k nF. AT42QT1012 1 OUT Rt 6 TIME Ct Rop between 4 and 240. ------------------ - K 14. Figure 3-8 on ...
Page 14
... Decide on a value for (for example nF) 5. Calculate Verify that As an alternative to calculation, curves of auto-off delay against resistor and capacitor values for active high and active low outputs at various values of VDD (delay multiplier = x1). AT42QT1012 14 Typical Values of K Versus Supply Voltage Active High Output 2 ...
Page 15
... Ct = 47nF Ct = 22nF Ct = 10nF 50 100 150 200 Timing Resistor Rt (K ohms) 3V Active High Ct = 47nF Ct = 100nF Ct = 22nF Ct = 10nF 50 100 150 200 Timing Resistor Rt (K ohms) AT42QT1012 4V Active High 4000 Ct = 100nF Ct = 47nF 3500 3000 2500 2000 1500 1000 500 0 250 0 50 100 150 Timing Resistor Rt (K ohms) ...
Page 16
... This shows the following suitable combinations: – 100 k – k – k – 190 k Note: the Auto-off delay times shown are nominal and will vary from chip to chip and with capacitor and resistor tolerance. AT42QT1012 Vss (delay multiplier = x1) 5V Active Low Ct = 22nF Ct = 47nF Ct = 10nF ...
Page 17
... Vm returns to original state SENSE ELECTRODE VDD 5 RS VDD 3 SNSK CS 4 SNS OUT TIME Rm VSS 2 VDD Vm VSS Tp AT42QT1012 and Figure 3-12 on page 18. Table 1 6 Rop 3-6. 17 ...
Page 18
... Figure 3-12. Override Pulse (Delay Multiplier x24) Figure 3-13 Figure 3-13. Overriding Auto Off AT42QT1012 18 SENSE ELECTRODE VDD 5 RS VDD 3 SNSK CS 4 SNS Rm VSS 2 VDD Vm VSS Tp shows override pulses being applied to a QT1012 with delay multiplier set to x1. OUT Bursts SNSK ...
Page 19
... SNS Auto off time obtained from 3V chart in Active high, driving high impedance, auto off time 315s 5.25 minutes 100nF SENSE ELECTRODE Rs 3 SNSK CS 4 SNS Rm 1M Auto off time obtained from 5V chart in AT42QT1012 +3V DTA143 5 1 OUT Rt 10k 6 TIME 2.2k 47nF Ct VSS 2 ...
Page 20
... Rs resistor and the electrode should not run near ground, to reduce loading. For best EMC performance the circuit should be made entirely with SMT components. AT42QT1012 20 for the power supply range. ...
Page 21
... On initial power up, the QT1012 requires approximately 250 ms to power on to allow power supplies to stabilize. During this time the OUT pin state is not valid and should be ignored. Note that recalibration takes approximately 200 ms, so the QT1012 takes approximately 450 ms in total from initial power on to become active. 9543D–AT42–08/10 AT42QT1012 21 ...
Page 22
... Time between end of burst and start of the next (Fast mode) Time between end of burst and start of the next (LP mode) T Burst length BL T Response time R AT42QT1012 22 -40°C to +85°C -55°C to +125° +6.5V ±20 mA Infinite Infinite -0. 0.6) Volts DD +1.8 to 5.5V ±20 mV ±100 mV 2 ...
Page 23
... Vdd 0.3 Vdd 0.7 Vdd 0.6 Vdd 0.6 V -0.7 DD ±1 µA 0 100 bits AT42QT1012 Notes Notes V 1.8V 2.0V 3.0V 4.0V 5.0V Required for proper start-up Vdd = 1.8V – 2.4V V Vdd = 2.4V – 5.5V Vdd = 1.8V – 2.4V V Vdd = 2.4V – 5.5V ...
Page 24
... Mold Flash, protrustion or gate burrs shall not exceed 0.25 mm per end. 3. Dimension b does not include dambar protrusion. Allowable dambar protrusion shall not cause the lead width to exceed the maximum b dimension by more than 0. Die is facing down after trim/form. Package Drawing Contact: packagedrawings@atmel.com AT42QT1012 Side View ...
Page 25
... Package Drawing Contact: packagedrawings@atmel.com 9543D–AT42–08/ TITLE 8PAD, 2x2x0.6 mm body, 0.5 mm pitch, 0.9x1.5 mm exposed pad, Saw singulated Thermally enhanced plastic ultra thin dual flat no lead package (UDFN/USON) AT42QT1012 8x 0. 0.05 c SIDE VIEW A1 A COMMON DIMENSIONS (Unit of Measure = mm) SYMBOL MIN NOM ...
Page 26
... AT42QT1012– 8-pin UDFN/USON Abbreviated Part Number: 1012 AT42QT Class code (H = Industrial, green NiPdAu) Pin 1 ID 5.8 Part Number Part Number AT42QT1012-TSHR AT42QT1012-MAH 5.9 Moisture Sensitivity Level (MSL) AT42QT1012 26 Abbreviated 1012 Part Number: AT42QT 1012 HEC YZZ Pin 1 Last Digit of Year ...
Page 27
... Revision History Revision No. Revision A – August 2009 Revision B – September 2009 Revision C – May 2010 Revision D – August 2010 9543D–AT42–08/10 AT42QT1012 History Initial release for chip revision 2.4 Changes to Cs value. Updated for chip revision 3.1 ...
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... LOSS OF INFORMATION) ARISING OUT OF THE USE OR INABILITY TO USE THIS DOCUMENT, EVEN IF ATMEL HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. Atmel makes no representations or warranties with respect to the accuracy or completeness of the contents of this document and reserves the right to make changes to specifications and product descriptions at any time without notice. Atmel does not make any commitment to update the information contained herein. Unless specifically provided otherwise, Atmel products are not suitable for, and shall not be used in, automotive applications. Atmel’ ...