6.4 Device Functional Modes

6.4.1 Normal Operation

The device regulates to the nominal output voltage under the following conditions:

• The input voltage is at least as high as VIN(min).

• The input voltage is greater than the nominal output voltage added to the dropout voltage.

• The enable voltage is greater than VEN(min).

• The output current is less than the current limit.

• The device junction temperature is less than the maximum specified junction temperature.

6.4.2 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 of operation, the

output voltage is the same as the input voltage minus the dropout voltage. The transient performance of the

device is significantly degraded because the pass device is in the linear region and no longer controls the current

through the LDO. Line or load transients in dropout can result in large output voltage deviations.

6.4.3 Disabled

The device is disabled under the following conditions:

• The enable voltage is less than the enable falling threshold voltage or has not yet exceeded the enable rising

threshold.

• The device junction temperature is greater than the thermal shutdown temperature.

• The input voltage is less than UVLOfalling.

Table 6-1 lists the conditions that lead to the different modes of operation.

Table 6-1. Device Functional Mode Comparison

OPERATING

MODE

PARAMETER

VIN

VEN

IOUT

TJ

Normal mode

VIN > VOUT(nom) + VDO and

VIN>VIN(min)

VEN > VEN(high)

IOUT < ILIM

TJ < 125°C

Dropout mode

VIN(min) < VIN< VOUT(nom) + VDO

VEN > VEN(high)

—

TJ < 125°C

Disabled mode

(any true

condition

disables the

device)

VIN < UVLOfalling

VEN < VEN(low)

—

TJ > 165°C(1)

(1)

Approximate value for thermal shutdown

TPS792

SLVS337E – MARCH 2001 – REVISED JANUARY 2025

www.ti.com

18

Submit Document Feedback

Copyright © 2025 Texas Instruments Incorporated

Product Folder Links: TPS792