Realtek Semiconductor Inc.

Ying-Chuan Peng

Yi-Chang Tu

Sheng-Nan Chiu

Po-Chiang Wu

Chia-Liang Chiang

Chung-Ting Yang

Shan-Ting Hong

Ching-Hsien Liao

Show-Hong Chen

Shan Ting Hong

An audio multi-standard detection apparatus is provided to pre-record a plurality of audio broadcasting format carrier bands. The detection apparatus includes: a carrier calculation unit and a switch controller. The carrier calculation unit is used for receiving an intermediate frequency signal and calculates the first carrier energy of the intermediate frequency signal in each of the frequency bands. From this first carrier energy, the switch controller determines which frequency bands are existed in the intermediate frequency signal, then analyzes the signal via at least one threshold value to determine the frequency band's primary carrier. The switch controller obtains an effective carrier. Further, the switch controller compares the effective carrier with the pre-recorded carrier bands for selectively outputting the appropriate audio broadcasting format. Hence, the present invention achieves the objective of determining the appropriate audio multi-standard and enables the support of broadcast systems in various countries with a single audio decoding chip.

TV audio multi-standard detection apparatus and method

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.

Test circuit for programmable gain amplifier

Growing community of inventors

Hsinchu County, Taiwan

Ying-Chuan Peng