kludge@pyr.gatech.edu (Scott Dorsey) (01/25/90)
Spring is here! Even though it's still January, the new op-amps are coming out. Today's batch of datasheets includes an improved AD712 from analog devices, called the AD748. Bandwidth and slew rate are improved somewhat, though I am not sure of the noise figure because the sheet I have is rather preliminary. Overall it looks like it might be worth a try, and they tell me that samples will be available soon. The other neat beastie is something from National called the LM6118. Also a dual part, also compatible with the LM833 pinout so you can put it in your Magnavox CD player. This is another very-wide-bandwidth chip, even wider than the MC34082 (which is presently in my CD player and also serving as a video distribution amp so that my VCR can drive an old Conrac hires monitor). Ft is 17 MHz which is fairly respectable for something unity-gain-compensated. The slew rate is given as a pair of numbers: for decreasing (Av=-1), it's 140 V/uS, and for increasing i(Av=1), it's 75 V/uS. Not bad overall, though drive capability is pretty limited. Strange PNP output stuff that I don't understand, but they are sampling it (regretfully only in plastic packages), so get some and try them. Even at list price it's cheaper than a 6DJ8. --scott