Datasheet

TPS63030
TPS63031
SLVS696B –OCTOBER 2008–REVISED MARCH 2012 www.ti.com
Device Enable
The device is put into operation when EN is set high. It is put into a shutdown mode when EN is set to GND. In
shutdown mode, the regulator stops switching, all internal control circuitry is switched off, and the load is
disconnected from the input. This also means that the output voltage can drop below the input voltage during
shutdown. During start-up of the converter, the duty cycle and the peak current are limited in order to avoid high
peak currents flowing from the input.
Softstart and Short Circuit Protection
After being enabled, the device starts operating. The average current limit ramps up from an initial 400mA
following the output voltage increasing. At an output voltage of about 1.2 V, the current limit is at its nominal
value. If the output voltage does not increase, the current limit will not increase. There is no timer implemented.
Thus the output voltage overshoot at startup, as well as the inrush current, is kept at a minimum. The device
ramps up the output voltage in a controlled manner even if a very large capacitor is connected at the output.
When the output voltage does not increase above 1.2 V, the device assumes a short circuit at the output and
keeps the current limit low to protect itself and the application. At a short at the output during operation the
current limit also will be decreased accordingly. At 0 V at the output, for example, the output current will not
exceed about 400 mA.
Undervoltage Lockout
An undervoltage lockout function prevents device start-up if the supply voltage on VINA is lower than
approximately its threshold (see electrical characteristics table). When in operation, the device automatically
enters the shutdown mode if the voltage on VINA drops below the undervoltage lockout threshold. The device
automatically restarts if the input voltage recovers to the minimum operating input voltage.
Overtemperature Protection
The device has a built-in temperature sensor which monitors the internal IC temperature. If the temperature
exceeds the programmed threshold (see electrical characteristics table) the device stops operating. As soon as
the IC temperature has decreased below the programmed threshold, it starts operating again. There is a built-in
hysteresis to avoid unstable operation at IC temperatures at the overtemperature threshold.
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