Title :
Operational amplifier power optimization for a given total (slewing plus linear) settling time
Author :
Silveira, Fernando ; Flandre, Denis
Author_Institution :
Instituto de Ingenieria Electrica, Univ. de la Republica, Montevideo, Uruguay
Abstract :
A design procedure that determines the combination of linear settling time (i.e. gain bandwidth) and slew rate that minimizes an amplifier total power consumption, while complying with a given total settling time specification, is presented. The method is presented for a Miller OTA, but can be generalized to other architectures. The proposed approach also provides the optimum combination of the gm/ID ratios of the input and output transistors and the transistor design corresponding to this optimum of power consumption. It is shown that the application of fixed "rules of thumb" criteria for the assignment of the allowable linear settling and slewing periods leads to highly increased consumption. The method is based on a simple, design oriented model of the settling behavior that is also described in this paper. This model is checked against experimental results and the design procedure results are verified with SPICE simulations.
Keywords :
SPICE; circuit CAD; circuit optimisation; circuit simulation; operational amplifiers; Miller OTA; SPICE simulations; allowable linear settling periods; allowable slewing periods; amplifier power consumption; design oriented model; design procedure; design verification; gain bandwidth; input transistors; linear settling time; operational amplifier power optimization; optimum power consumption; optimum transconductance/drain current ratios; output transistors; settling behavior; slew rate; total settling time specification; total slewing/linear settling time; transistor design; Bandwidth; Design optimization; Energy consumption; Filters; Frequency response; Operational amplifiers; Power amplifiers; SPICE; Time factors; Transconductance;
Conference_Titel :
Integrated Circuits and Systems Design, 2002. Proceedings. 15th Symposium on
Print_ISBN :
0-7695-1807-9
DOI :
10.1109/SBCCI.2002.1137666