Patent ID: 8175824
Filing Date: 2012-05-08
Classification: G01R

Abstract:
1. A circuit testing apparatus for testing capacitance of a capacitor of a device under test, comprising: a measuring module for outputting a testing signal, and determining said capacitance of said capacitor according to a signal measuring result of said testing signal; a first converting module coupled to said measuring module for receiving and converting said testing signal to generate a testing input signal; a processing module coupled to said first converting module and said device under test for receiving and transmitting said testing input signal to said capacitor, and amplifying an output signal generated by said capacitor to generate an amplified signal; and a second converting module coupled to said processing module and said measuring module for converting said amplified signal to generate said signal measuring result, wherein said processing module comprises: a first switch with a terminal coupled to said first converting module; a second switch; a first resistor with a terminal coupled to said first switch, and another terminal of said first resistor coupled to said second switch; a third switch with a terminal coupled to said first converting module and another terminal of said third switch coupled to a terminal of said capacitor; a fourth switch with a terminal coupled to another terminal of said capacitor; an amplifier having a non-negative input terminal, a negative input terminal and an output terminal, wherein said negative input terminal is coupled to another terminal of said second switch and another terminal of said fourth switch, and said non-negative input terminal is coupled to a ground, and wherein said amplifier amplifies said output signal to generate said amplified signal; a fifth switch with a terminal coupled to said first converting module and another terminal of said fifth switch coupled to said output terminal of said amplifier; a second resistor coupled between said output terminal and said negative input terminal of said amplifier; and a sixth switch with a terminal coupled to said output terminal of said amplifier and another terminal of said sixth switch coupled to said second converting module.