AT42QT1010-TSHR Detailed explanation of pin function specifications and circuit principle instructions

The AT42QT1010-TSHR is a product from Microchip Technology. It is a capacitive touch sensor controller, and the "TSHR" part refers to its packaging type, specifically a QFN-16 package (16-pin, quad flat no-lead). Below, I will provide the requested information in an organized and detailed manner.

Pin Function Specifications and Circuit Principle

Packaging: QFN-16 Pin Count: 16 pins (not 200 pins as mentioned). Pin Function List for AT42QT1010-TSHR (QFN-16 Package) Pin Number Pin Name Pin Function Description 1 VDD Power supply pin (2.5V to 3.6V). This pin is used to provide the power to the device. It must be connected to a stable power source for proper operation. 2 GND Ground pin. This pin is used for the common ground reference and must be connected to the system ground. 3 X1 Input to the first electrode of the capacitive touch sensor. This pin is used to connect to the external sensor electrode. 4 X2 Input to the second electrode of the capacitive touch sensor. This pin connects to the second external sensor electrode. 5 Y1 Output of the first capacitive touch sensor electrode. Used for sensing changes in capacitance when the sensor is touched. 6 Y2 Output of the second capacitive touch sensor electrode. Detects changes in capacitance when the sensor is activated. 7 NC No connection. This pin is unused and should be left unconnected in the circuit. 8 NC No connection. This pin is unused and should be left unconnected in the circuit. 9 INT Interrupt output pin. This pin is used to signal when a touch event is detected by the controller. It can trigger an interrupt to notify the host microcontroller. 10 RST Reset pin. It is used to reset the device to its initial state. Typically driven by an external controller to trigger a reset operation. 11 OSC1 Oscillator input pin. This pin is connected to an external crystal or resonator to provide the clock signal for the device. 12 OSC2 Oscillator output pin. It provides the clock signal from the external oscillator to the controller. 13 VSS Ground reference for the touch sensor input/output interface . This pin is also connected to the system ground. 14 VDDIO IO Voltage supply pin. Typically connected to the same voltage as the system logic (2.5V to 3.6V). This is where the IO logic is powered. 15 TXD Transmit data pin for serial communication (UART). Used to send data from the AT42QT1010 to a connected system. 16 RXD Receive data pin for serial communication (UART). Used to receive data from a connected system to the AT42QT1010. Circuit Principle

The AT42QT1010 operates using a capacitive touch sensing method, detecting the variation in capacitance caused by a human finger or conductive object near the electrodes. The basic principle involves applying an AC signal to the electrodes (X1, X2), and the device monitors changes in capacitance at the outputs (Y1, Y2) corresponding to the electrodes. These changes are processed by the device’s internal circuitry and can trigger an interrupt (INT) or communicate via UART (TXD/RXD).

Pin Function FAQ (20 Questions)

Q: What is the operating voltage range of the AT42QT1010-TSHR? A: The AT42QT1010-TSHR operates within a voltage range of 2.5V to 3.6V. Q: How many pins are there in the AT42QT1010-TSHR? A: The AT42QT1010-TSHR has 16 pins in total. Q: What is the function of the VDD pin on the AT42QT1010-TSHR? A: The VDD pin provides the power supply to the device. It must be connected to a stable voltage source (2.5V to 3.6V). Q: What is the purpose of the GND pin? A: The GND pin is the ground reference for the device and must be connected to the system ground. Q: What are the X1 and X2 pins used for? A: The X1 and X2 pins are inputs to the capacitive touch sensor electrodes. These pins should be connected to the external electrodes of the sensor. Q: What do the Y1 and Y2 pins do? A: The Y1 and Y2 pins are used to output the signals corresponding to the capacitive touch detection. These pins provide information when a touch event is detected. Q: Can I leave the NC pins unconnected? A: Yes, the NC (No Connection) pins should be left unconnected in your circuit. Q: What is the role of the INT pin? A: The INT pin is an interrupt output that signals when a touch event is detected, notifying the host microcontroller. Q: How does the RST pin work? A: The RST pin is used to reset the device. It is typically driven by an external controller to trigger a reset operation.

Q: What is the OSC1 and OSC2 used for in the AT42QT1010?

A: OSC1 is the oscillator input pin, and OSC2 is the oscillator output pin. Together, they generate the clock signal for the device.

Q: What does the TXD pin do?

A: The TXD pin is used for transmitting data from the AT42QT1010 to another system through UART communication.

Q: What is the RXD pin used for?

A: The RXD pin is used for receiving data from an external system into the AT42QT1010 via UART communication.

Q: What is the maximum input capacitance for the AT42QT1010-TSHR?

A: The input capacitance is typically up to 20 pF for the sensor electrodes.

Q: Can the AT42QT1010-TSHR be used in battery-powered applications?

A: Yes, the AT42QT1010 is designed for low-power consumption, making it suitable for battery-powered applications.

Q: How many touch sensors can the AT42QT1010 support?

A: The AT42QT1010 supports up to two capacitive touch sensors through its X1, X2, Y1, and Y2 pins.

Q: What is the function of the VDDIO pin?

A: The VDDIO pin supplies power to the I/O logic of the device. It should be powered with the same voltage as the system logic (2.5V to 3.6V).

Q: Can the AT42QT1010-TSHR be directly interfaced with an external display?

A: The AT42QT1010-TSHR is primarily for touch sensing and does not directly drive displays. You will need an external microcontroller to process touch data and drive the display.

Q: Is the AT42QT1010-TSHR compatible with 5V systems?

A: No, the AT42QT1010-TSHR operates at 2.5V to 3.6V, so it is not directly compatible with 5V systems without level shifting.

Q: What type of sensor does the AT42QT1010-TSHR support?

A: The AT42QT1010-TSHR supports capacitive touch sensors.

Q: Can I use the AT42QT1010 for multi-touch sensing?

A: No, the AT42QT1010-TSHR supports a single touch input, not multi-touch.

This provides the detailed explanation, pin function list, and a comprehensive FAQ for the AT42QT1010-TSHR, covering all the essential aspects requested.