t

=

(120

R )

(120+R )

L

L

·

·

C

OUT

Thermal

Shutdown

Current

Limit

UVLO

Bandgap

IN

EN

OUT

LOGIC

GND

TLV702xxPSeries

120W

11

TLV702

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SLVSAG6D – SEPTEMBER 2010 – REVISED JULY 2019

Product Folder Links: TLV702

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Copyright © 2010–2019, Texas Instruments Incorporated

Functional Block Diagrams (continued)

Figure 24. TLV702P Block Diagram

7.3 Feature Description

7.3.1 Internal Current Limit

The TLV702 internal current limit helps to protect the regulator during fault conditions. During current limit, the

output sources a fixed amount of current that is largely independent of the output voltage. In such a case, the

output voltage is not regulated, and is VOUT = ICL × RLOAD. The PMOS pass transistor dissipates (VIN – VOUT) ×

ICL until thermal shutdown is triggered and the device turns off. As the device cools, it is turned on by the internal

thermal shutdown circuit. If the fault condition continues, the device cycles between current limit and thermal

shutdown. See Thermal Consideration for more details.

The PMOS pass element in the TLV702 has a built-in body diode that conducts current when the voltage at OUT

exceeds the voltage at IN. This current is not limited, so if extended reverse voltage operation is anticipated,

external limiting to 5% of the rated output current is recommended.

7.3.2 Shutdown

The enable pin (EN) is active high. The device is enabled when voltage at EN pin goes above 0.9 V. The device

is turned off when the EN pin is held at less than 0.4 V. When shutdown capability is not required, EN can be

connected to the IN pin.

The TLV702P version has internal active pulldown circuitry that discharges the output with a time constant of:

where:

•

RL = Load resistance

•

COUT = Output capacitor

(1)