| 摘要 |
PURPOSE:To perform level adjustment simply and surely, by connecting a reference CODEC opposingly and adjusting a coder and a decoder of an analog/ digital conversion circuit. CONSTITUTION:An analog test signal OSC is inputted from two-line side of an analog/digital conversion circuit AD, an analog signal output leve of connected reference CODEC is measured and an LV and a coder COD are adjusted VRc. Further, the analog test signal OSC is inputted to the reference codec CODEC to measure the analog signal output level of the two-wire side of the AD and the LV and a decoder DEC are adjusted VRD, then the level adjustment can be done with the state very close to the actual operating state, the adjusting work can be simplified and the level adjusting method like this can be made highly reliable and efficient. |
