This circuit is from Motorola's Linear Interface ICs from 1993. The MC1723 is the equivalent of the well-known 723. The transistor supports equivalents.
Found in old Philips documentation, this circuit uses components from the 60's. | Clique na imagem...
The circuit shown uses the LM324, but can be implemented with other operational ones. The source...
Found in Linear Technology documentation, this circuit drains only 70 uA of the monitored circuit....