Low-voltage digitally controlled current differencing buffered amplifier and its application

Z Copy‐Controlled Gain‐Current Differencing Buffered Amplifier and its applications

“…However, it is advantageous in terms of the dynamic range when its absolute value does not exceed the unity value. Then the CCF can be substituted by the CDN block from 69 or by its analog equivalent of current attenuation. Of course, neither the method nor the range of current gain control are specified in definition equations (2).…”

“…Transistor structures of the CDU, designed in the CMOS 38, 39 and bipolar 40 technologies, are described in several papers. Similar designs of circuits for current gain control also exist 24, 69. A principle of z ‐current sensing and copying is proposed in 70.…”

“…Over the last decade, we have witnessed extensive research into modern active electronic elements and their utilization in various application circuits for analog signal processing 1–70. Voltage‐feedback and current‐feedback operational amplifiers 1–3, Operational Transconductance Amplifiers (OTAs) 4–8, several types of current or voltage conveyors 9–21, and others 22–31 belong to frequently used building blocks.…”

“…Nevertheless, CC‐CDBA can be utilized, among other things, for economical implementation of circuits with minimum number of components 67, 68. Another method of controlling the CDBA parameters is shown in 69 as the DC‐CDBA element (Digitally Controlled CDBA). The output current of the CDU is modified in the block called Current Division Network (CDN).…”

“…This problem can be solved by an auxiliary circuitry that reconstructs the I z current as a linear combination of other currents in the circuit on the basis of Kirchhoff's Current Law. However, this approach requires making copies of some existing currents, for example a copy of the input current 69, which can be inconvenient in terms of high sensitivity of the resulting transfer functions to the accuracy of such a copy 6.…”