Post by thread:[EE] National Semiconductor application notes

> <http://www.national.com/an/AN/> > > AN-4 Monolithic Op-Amp (1968) > ... > AN-1898 LVDS Repeaters (Sept. 2008) > > > -- > Martin It was neat looking back at AN-4. The current boost output (what I call a complementary emitter follower) reminds me of a clever circuit I saw many years ago. The op amp power supply leads went to their supplies through small resistors. The power supply pins of the op amps also were connected to the bases of a complementary pair of transistors (PNP on positive, NPN on negative). The emitters were connected to the appropriate supply. The collectors were tied to the op amp output. As the op amp tried to draw more current to drive the load, the corresponding transistor would come on and supply the load. Harold -- FCC Rules Updated Daily at http://www.hallikainen.com - Advertising opportunities available!

On Tue, Oct 7, 2008 at 12:57 AM, Martin <spam_OUTmartinTakeThisOuTnnytech.net> wrote: > <http://www.national.com/an/AN/> > > AN-4 Monolithic Op-Amp (1968) > ... > AN-1898 LVDS Repeaters (Sept. 2008) Where do you use LVDS? Do you use it to replace RS485? M-LVDS looks nice as well to replace multi-drop RS485. Xiaofan

>The emitters were connected to the appropriate supply. The >collectors were tied to the op amp output. As the op amp tried >to draw more current to drive the load, the corresponding >transistor would come on and supply the load. Quad made an audio amplifier that worked like this. IIRC they called it a 'current dumping' amplifier.

>Where do you use LVDS? Do you use it to replace RS485? >M-LVDS looks nice as well to replace multi-drop RS485. LVDS is used in fast interfaces - we use it for an interface known as Spacewire, which is a ESA originated Firewire like interface for handling video and other high speed datastreams on satellites. It can go up to several hundred MHz bit rate, where RS485 and the like are in the 10's MHz.