Datasheet

TPS62065, TPS62067

SLVS833B –MARCH 2010–REVISED NOVEMBER 2013

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This limits the inrush current in the converter during start up and prevents possible input voltage drops when a

battery or high impedance power source is used.

During soft start, the switch current limit is reduced to 1/3 of its nominal value ILIMF until the output voltage

reaches 1/3 of its nominal value. Once the output voltage trips this threshold, the device operates with its

nominal current limit I

LIMF

INTERNAL CURRENT LIMIT / FOLD-BACK CURRENT LIMIT FOR SHORT-CIRCUIT PROTECTION

During normal operation the High-Side and Low-Side MOSFET switches are protected by its current limits I

LIMF

Once the High-Side MOSFET switch reaches its current limit, it is turned off and the Low-Side MOSFET switch is

turned on. The High-Side MOSFET switch can only turn on again, once the current in the Low -Side MOSFET

switch decreases below its current limit I

LIMF

. The device is capable to provide peak inductor currents up to its

internal current limit

ILIMF.

As soon as the switch current limits are hit and the output voltage falls below 1/3 of the nominal output voltage

due to overload or short circuit condition, the foldback current limit is enabled. In this case the switch current limit

is reduced to 1/3 of the nominal value I

LIMF

Due to the short-circuit protection is enabled during start-up, the device does not deliver more than 1/3 of its

nominal current limit I

LIMF

until the output voltage exceeds 1/3 of the nominal output voltage. This needs to be

considered when a load is connected to the output of the converter, which acts as a current sink.

CLOCK DITHERING

In order to reduce the noise level of switch frequency harmonics in the higher RF bands, the TPS6206x family

has a built-in clock-dithering circuit. The oscillator frequency is slightly modulated with a sub clock causing a

clock dither of typ. 6ns.

THERMAL SHUTDOWN

As soon as the junction temperature, T

, exceeds 150°C (typical) the device goes into thermal shutdown. In this

mode, the High-Side and Low-Side MOSFETs are turned off. The device continues its operation with a softstart

once the junction temperature falls below the thermal shutdown hysteresis.

Product Folder Links :TPS62065 TPS62067