E-L293DD Datasheet, PDF (12/17 Pages) STMicroelectronics – 2.5 A switch step down switching regulator

Application ideas
L5973D
When an output voltage below the internal reference (1.235 V) is required, the circuit
reported in the figure 18 can been used. In this case the minimum voltage reachable is 0.6 V
and can be easily calculated with the following formula:
V_OUT = V_FB - [(V_REF - V_FB)x(R₂ / R₁)]
If the load is not present, a resistor connected between V_OUT and GND is required in order
to avoid that the voltage across C_OUT increases.
The value of this resistor has to be calculated taking into account that the current flowing
through this resistance has to be higher than the current flowing through R₂.
Figure 19. Output voltage below the 1.235 V internal voltage reference
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