Connecting a low-dropout regulator's enable pin directly to the unregulated voltage input forces the output voltage to track the input voltage during the regulator's turn-on and turn-off intervals
| Authors | William Lepkowski |
| Main Document | Article «Low-dropout linear regulators double as voltage-supervisor circuits» |
| Description | Figure 1 |
| File Format / Size | PDF / 77 Kb |
| Document Language | English |
Other Materials from the Main Document
- Article «Low-dropout linear regulators double as voltage-supervisor circuits»
- Figure 1. Connecting a low-dropout regulator's enable pin directly to the unregulated voltage input forces the output voltage to track the input voltage during the regulator's turn-on and turn-off intervals
- Figure 2. An alternative to directly connecting the regulator's input and enable pins, this "conventional" modification uses a resistor and a capacitor to delay the regulator's turn-on time. The diode eliminates the powerdown delay interval
- Figure 3. The added components in Figure 2 eliminate the problem of rising-edge output-voltage tracking. However, the falling-edge output voltage still tracks the input voltage
- Figure 4. Resistor R2 increases the enable pin's switching threshold voltage
- Figure 5. The addition of R2 in Figure 3 solves the falling edge problem, and shutdown occurs immediately after the input voltage drops too low. The regulator's output switches on only after sufficient voltage is present at its input
