Doubt, clarification

Hi Miguel, the Sense pin is tied directly to the Zener, while the Force pin carries the Shunt current. ADR1399 does not push all shunt current through the internal Zener, it biases the Zener with a fixed current and then pushes any additional shunt current around the reference via the npn transistor shown in Figure 35. Neither path is zero-current, we chose the names of the pins to show that the force pin is likely less accurate than the sense pin due to additional IR drop. Pin 6 and pin 7 are indeed separate paths. In any use-case, the direct Zener voltage is the "sense" path (+/-REFS), and the more accurate path.

Thank you very much for the answer, if I understand correctly, the operation of the ADR1399 is the same as that of the LTZ1000, except for the second transistor that the LTZ1000 has. The base of the transistor in the ADR1399 is internally connected to the cathode of the zener diode, correct? This is not explicit in any of the figures in the data sheet.

Thank you Miguel

Hi Miguel, ADR1399 is a quite different circuit from LTZ1000. ADR1399 has a circuit that is similar to the circuit in the LM399, as shown in that datasheet. Please note that the ADR1399 block diagram shows a single Zener diode for conceptual purposes only - the circuit is far more complex.

Hi Miguel, ADR1399 is a quite different circuit from LTZ1000. ADR1399 has a circuit that is similar to the circuit in the LM399, as shown in that datasheet. Please note that the ADR1399 block diagram shows a single Zener diode for conceptual purposes only - the circuit is far more complex.