TPS65235 has a dedicated EN pin to disable and enable the LNB output. At non-I²C application, when the EN pin is pulled to high, the LNB output is enabled, when the EN pin is pull to low, the LNB output is disabled. At I²C application, either EN pin is low or high, the I²C registers can be accessed, which allows customer to change the default LNB output when system power up. When the bit I2C_CON of Control Register 1 is set to “1”, the LNB output enable or disable is controlled by bit EN of Control Register 2. By default, the bit I2C_CON of the control register is set to “0”, which makes the LNB output is controlled by the EN pin. Figure 7-3 and Figure 7-4 shows the detail control behavior.

EN pin = 0 V

Bit I2C_CON = 1

Figure 7-3 VLNB Output Controlled by bit EN of Control Register 2

Bit I2C_CON = 0

Figure 7-4 VLNB Output Controlled by EN Pin