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[Torex] The latest solution to the freezing of TWS system
- Author:TOREX
- Release on:2021-01-12
How to reset or restart a true wireless stereo device
Simple solution using low cost voltage detector
True wireless stereo (TWS) earbuds and headphones are sometimes susceptible to system freezing.For other wireless devices, such as mobile phones and smart watches, there is usually a button that allows you to easily reset or restart the device.However, due to the size limitations usually associated with TWS devices, the buttons for operating this process are not always available. If buttons are present, they are usually dedicated to the general control functions of the TWS device.
Sometimes, the microprocessor in the TWS device will have an internal reset function, but if the system "freezes", the microprocessor may not work properly to activate the system reset.
Circuit and description
For the above situation, there is no reset button available. We recommend using our XC6135 ultra-low power voltage detector. The following circuit is recommended.In the example shown here, an active high variant of the XC6135 is used.It interacts with the charging dock to overcome the system freezing problem.
To illustrate this operation, we assume that the cradle is not inserted at the beginning, and the voltage shown as the "slave cradle" in the above figure is lower.
1. The TWS device enters the charging dock.
2. Now, the power cord labeled "From Cradle" has been connected to the input pin VSEN of XC6135.
3. Close the cover of the cradle and/or insert the cradle.
4. The voltage on the power cord marked "From Cradle" suddenly rises to a certain DC voltage value.For example, it can be 5.0V.
5. The VSEN pin monitors the voltage of the cradle. When it reaches the release voltage level of the XC6135 voltage detector, the logic output signal switches from a high level to a low level.
6. This low signal is used to reset the microprocessor.
7. Later, remove TWS from the cradle.
8. The voltage on the VSEN pin drops suddenly.When the voltage drops below the detection voltage value, the logic output switches from low to high.
9. The SoC starts again, and the smartphone or other devices used with TWS can be reconnected.
Using this circuit, regardless of whether the system is in a frozen state, it will automatically reset every time the microprocessor in the TWS is put back into the charging dock, so there is no need to use the device to detect the "frozen" state.
XC6135 summary
With separate detection pins
ofUltra-low power (44nA) voltage detectorThe XC6135 series is an ultra-low power voltage detector that can detect voltages as low as 0.5 V. This makes it ideal for monitoring 0.7 V and 0.8 V voltage rails. The core voltage SoC is manufactured using 16 nm and 28 nm processes.
The operating voltage range is 1.1 V to 6.0V. With a quiescent current of only 44 nA, the XC6135 helps to extend the working life of battery-powered devices such as IoT devices, wearable devices and smart meters.
This series has a separate detection pin function, when combined with an external divider, it can detect high withstand voltage.
Available in CMOS and open-drain versions, as well as active low and active high output logic options.XC6135 is available in SOT-25 and SSOT-24 packages and ultra-compact (1.0 mm x 1.0 mm x 0.33 mm) USPQ-4B05 package.
USPQ-4B05
Availability
The samples of the XC6135 series mentioned above are already available, so please ask your local Torex representative for detailed information, or contact us directly through our website.