Title :
A versatile building block: the CMOS differential difference amplifier
Author :
Säckinger, Eduard ; Guggenbuhl, W.
fDate :
4/1/1987 12:00:00 AM
Abstract :
An extension of the op-amp concept featuring two differential inputs is presented. In a closed-loop environment this circuit forces two floating voltages to the same value, and thus has many interesting applications in the analog circuit domain. A description of such a circuit, its nonidealities, and restrictions are given. A monolithic integration of this differential difference amplifier is implemented in a double-poly CMOS technology, its measured characteristics are described. Many applications of this circuit, including a voltage comparator with floating inputs, a voltage inverter without resistors, and an instrumentation amplifier with only two external gain determining resistors, are discussed.
Keywords :
CMOS integrated circuits; Differential amplifiers; Linear integrated circuits; Operational amplifiers; differential amplifiers; linear integrated circuits; operational amplifiers; Analog circuits; CMOS technology; Differential amplifiers; Instruments; Integrated circuit measurements; Inverters; Monolithic integrated circuits; Operational amplifiers; Resistors; Voltage;
Journal_Title :
Solid-State Circuits, IEEE Journal of
DOI :
10.1109/JSSC.1987.1052715