SNVS037G – SEPTEMBER 1999 – REVISED JANUARY 2015
Typical Applications (continued)
8.2.9 Ripple Rejection Enhancement
A very simple ripple rejection circuit is shown in Figure 24 using the LM1084-ADJ. The capacitor C1 smooths out
the ripple on the output by cleaning up the feedback path and preventing excess noise from feeding back into the
regulator. Please remember XC1 should be approximately equal to R1 at the ripple frequency.
Figure 24. Ripple Rejection Enhancement
8.2.10 Automatic Light Control
A common street light control or automatic light control circuit is designed in Figure 25 based on the LM1084-
ADJ. The photo transistor conducts in the presence of light and grounds the ADJ pin preventing the lamp from
turning on. However, in the absence of light, the LM1084 regulates the voltage to 1.25V between OUT and ADJ,
ensuring the lamp remains on.
Figure 25. Automatic Light Control
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