| 摘要 |
PURPOSE:To attain conversion of a digital signal represented by the complement of 2 into alternate signal simply and with high accuracy by means of an exclusive OR circuit. CONSTITUTION:The Dn-th bit of an n-bit signal represented by the complement of 2 represents a sign. When the Dn is at ''0'', the sign is positive and when ''1'', it is negative. When the Dn is at ''0'', SW2, SW3 are turned on and SW1, SW4 are turned off among the sign changeover switches, and a terminal 10 goes to positive. Current sources I0-In and switches S0-Sn form a current summing type DA converting circuit, which generates an output current in response to the D0-Dn. When the Dn is at ''1'', the SW1, SW4 are turned on and the terminal 10 goes to negative. The D0-th-Dn-1-th bits control the switches S0-Sn-1 via the exclusive OR in order to express the complement of 2. To correct finally analog signals corresponding to the minimum bit, they are added. |
