22

TPS7A02

SBVS277B – JULY 2019 – REVISED MARCH 2020

www.ti.com

Submit Documentation Feedback

Copyright © 2019–2020, Texas Instruments Incorporated

7.4 Device Functional Modes

7.4.1 Device Functional Mode Comparison

The Device Functional Mode Comparison table shows the conditions that lead to the different modes of

operation. See the Electrical Characteristics table for parameter values.

Table 1. Device Functional Mode Comparison

OPERATING MODE

PARAMETER

Normal operation

Dropout operation

Disabled

(any true condition

disables the device)

Not applicable

7.4.2 Normal Operation

The device regulates to the nominal output voltage when the following conditions are met:

•

•

•

•

The enable voltage has previously exceeded the enable rising threshold voltage and has not yet decreased to

less than the enable falling threshold

7.4.3 Dropout Operation

If the input voltage is lower than the nominal output voltage plus the specified dropout voltage, but all other

conditions are met for normal operation, the device operates in dropout mode. In this mode, the output voltage

tracks the input voltage. During this mode, the transient performance of the device becomes significantly

degraded because the pass transistor is in the ohmic or triode region, and acts as a switch. Line or load

transients in dropout can result in large output-voltage deviations.

directly after being in a normal regulation state, but not during startup), the pass transistor is driven into the

ohmic or triode region. When the input voltage returns to a value greater than or equal to the nominal output

while the device pulls the pass transistor back into the linear region.

7.4.4 Disabled

The output of the device can be shutdown by forcing the voltage of the enable pin to less than the maximum EN

pin low-level input voltage (see the Electrical Characteristics table). When disabled, the pass transistor is turned

off, internal circuits are shutdown, and the output voltage is actively discharged to ground by an internal

discharge circuit from the output to ground.