suhas_shiv said:Opamp is used to drive loads which are resistive or capacitive, whereas OTAs are used to drive purely capacitive loads(small cap loads). Also except for the input/output node all other nodes in an OTA are low impedance nodes unlike an opamp. Usually an OTA has 2 stages with no buffer, whereas an Opamp has a buffer stage. If you need more information regarding design, please refer to the Book CMOS circuit design by baker and Boyce.
mengghee said:I am very new towards amp design.... what does purely resistive or capacitive load refer to ? can you give me a simple example of an implementation ? thank you very much