Typical Applications
The module is bus-powered and basic components are integrated, so it's very easy to use and some typical applications as follows:
Simplest application
Support suspend and remote wakeup
Using 5V to power other circuit
Virtual COM port
Following schematic shows a simple application. The LED can be connected to any GPIO or output pin, such as P3.0~P3.4, DTR or RTS. The K1 can be connected to any input pin or GPIO. Using a jumper to short the pin19 and pin20. Install the Apploader device driver and develop your 8051 code to handle the LED and K1. Plug-in the USB cable, that's it.
Support suspend and remote wakeup
The TUSB3410 can be put into suspend status by USB command and can be wakeup by push the wakeup button. R2 and R3 provides an external core 1.8V to power the core when the IC into the suspend status. For the reliable reason, a schottky diode is recommanded.
Using 5V to power other circuit
Due to the 5V is connected to the host 5V dircetly, any short circuit or heavy capacitive loads may damage or reset your host PC, especially for the low-end PC. So, some kinds of protection circuits are highly recommanded. The common way is to insert a current limit IC as follows.
The TPS2045A is a 250mA current limit power-distribution switch, which is intended for
applications where
heavy capacitive loads and short circuits are likely to be encountered. When the output load exceeds the current-limit
threshold or a short is present, these devices limit the output current to a safe level by switching into a constant-current
mode, pulling the overcurrent (OC) logic output low. When continuous heavy overloads and short circuits increase
the power dissipation in the switch, causing the junction temperature to rise, a thermal protection circuit shuts
off the switch to prevent damage. Recovery from a thermal shutdown is automatic once the device has cooled sufficiently.
Connections are simple. The EN can be grounded and the OC can be connected to any input pin, such as RI, DCD and so on. Remember, these pins have pullup onboard. If the OC pin is connected to the P3.0~P3.4, an external pullup is necessary, because the internal pullup is very week on those pins. It may report a wrong result.
To build a virtual COM port is straight. It can be just two wires (RXD, TXD) connection without any hardware handshaking or with full modem handshaking supported 8 lines interface. After installing the TI virtual COM port device driver, you can use it same as standard COM. Your circuit can be MCU or just a transceiver.