Datasheet

TPS63020

TPS63021

SLVS916C –JULY 2010–REVISED MARCH 2013

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Power Good

The device has a built in power good function to indicate whether the output voltage is regulated properly. As

soon as the average inductor current gets limited to a value below the current the voltage regulator demands for

maintaining the output voltage the power good output gets low impedance. The output is open drain, so its logic

function can be adjusted to any voltage level the connected logic is using, by connecting a pull up resistor to the

supply voltage of the logic. By monitoring the status of the current control loop, the power good output provides

the earliest indication possible for an output voltage break down and leaves the connected application a

maximum time to safely react.

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 1.2V, 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 large capacitor is connected at the output. When

the output voltage does not increase above 1.2V, the device assumes a short circuit at the output, and keeps the

current limit low to protect itself and the application. At a short on the output during operation, the current limit

also is decreased accordingly.

Overvoltage Protection

If, for any reason, the output voltage is not fed back properly to the input of the voltage amplifier, control of the

output voltage will not work anymore. Therefore overvoltage protection is implemented to avoid the output

voltage exceeding critical values for the device and possibly for the system it is supplying. The implemented

overvoltage protection circuit monitors the output voltage internally as well. In case it reaches the overvoltage

threshold the voltage amplifier regulates the output voltage to this value.

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.

Product Folder Links: TPS63020 TPS63021