SLVSGU2E February 2023 – April 2024 TLV709
PRODUCTION DATA
If the input voltage is lower than the nominal output voltage plus the specified dropout voltage, the device operates in dropout mode. However, make sure all other conditions are met for normal operation. In this mode, the output voltage tracks the input voltage. During this mode, the transient performance of the device becomes significantly degraded. The pass transistor is in the ohmic or triode region, and acts as a switch. Line or load transients in dropout result in large output voltage deviations.
When the device is in a steady dropout state, the pass transistor is driven into the ohmic or triode region. This state is defined as when the device is in dropout, directly after being in a normal regulation state, but not during start up. Dropout occurs when VIN < VOUT(NOM) + VDO. When the input voltage returns to a value ≥VOUT(NOM) + VDO, the output voltage overshoots for a short period of time. VOUT(NOM) is the nominal output voltage and VDO is the dropout voltage. During this time, the device pulls the pass transistor back into the linear region.