I

(mA)=C

( F)

0.07(V/ s)+I

(mA)

m

m

LOAD

SOFTSTART

OUT

´

Thermal

Shutdown

Current

Limit

UVLO

Bandgap

IN

EN

OUT

EEPROM

LOGIC

TPS727

www.ti.com

SBVS128F – JUNE 2009 – REVISED DECEMBER 2015

7 Detailed Description

7.1 Overview

The TPS727 devices belong to a family of LDO regulators that consume extremely low quiescent current while

good transient response. These features, combined with low noise without a noise reduction pin in an ultrasmall

package, make these devices ideal for portable applications. This family of regulators offers sub-band-gap output

voltages, current limit and thermal protection, and is fully specified from –40°C to +125°C.

7.2 Functional Block Diagram

7.3 Feature Description

7.3.1 Internal Current Limit

The TPS727 internal current limit helps protect the regulator during fault conditions. During current limit, the

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

until thermal shutdown is triggered and the device is turned off. As the device cools down, 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 the Thermal Protection section for more details.

The PMOS pass element in the TPS727 has a built-in body diode that conducts current when the voltage at the

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

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

7.3.2 Soft Start

The startup current is given by Equation 1:

(1)

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