Datasheet

Data Sheet ADR512
Rev. A | Page 9 of 12
PRECISE NEGATIVE VOLTAGE REFERENCE
The ADR512 is suitable for use in applications where a precise
negative voltage reference is desired, including the application
detailed in Figure 13.
Figure 14 shows the ADR512 configured to provide a −1.2 V
output.
ADR512
–1.2V
–V
DD
R2
+
–
03700-014
Figure 14. Precise −1.2 V Reference Configuration
Since the ADR512 characteristics resemble those of a Zener
diode, the cathode shown in Figure 14 will be 1.2 V higher with
respect to the anode (V+ with respect to V− on the ADR512
package). Since the cathode of the ADR512 is tied to ground,
the anode must be −1.2 V.
R1 in Figure 14 should be chosen so that 100 μA to 10 mA is
provided to properly bias the ADR512.
I
V
R
DD
=1
(5)
The resistor R1 should be chosen so that power dissipation is at
a minimum. An ideal resistor value can be determined through
manipulation of Equation 5.