Patent attributes
A test circuit, for checking whether at least one programmable gain amplifier (PGA) operates correctly, includes a signal generator, a gain controller, a test level output circuit, a comparison circuit and an identifying circuit. The signal generator is utilized for outputting a test input signal to a PGA to generate a test output signal. The gain controller is utilized for outputting a gain control signal to the PGA to adjust a gain of the PGA. The test level output circuit is utilized for referring to the test output signal to output a first test level and a second test level. The comparison circuit is utilized for comparing the first and second test levels to generate a result signal. The identifying circuit is utilized for identifying whether the PGA operates correctly according to the result signal.