Electronic card connector, level-shifting device and digital television receiver

An electronic card connector adapted to electrically connect an electronic card with an electronic device that is used with a first power source and a second power source, said electronic card connector comprising:

• an insert slot unit adapted for insertion of the electronic card and provided with a power signal terminal for providing electric power to the electronic card that is inserted into said insert slot unit;
• and
• a switch unit disposed in said insert slot unit and adapted to be electrically connected to the first and second power sources, said switch unit being operable to establish electrical connection between said power signal terminal and the first power source when the electronic card inserted into said insert slot unit does not actuate said switch unit, said switch unit being further operable to establish electrical connection between said power signal terminal and the second power source when the electronic card inserted into said insert slot unit actuates said switch unit.