SBVS067R January 2006 – December 2019 TPS737
PRODUCTION DATA.
The low open-loop output impedance provided by the NMOS pass element in a voltage follower configuration allows operation without a 1-µF output capacitor. As with any regulator, the addition of additional capacitance from the OUT pin to ground reduces undershoot magnitude but increases its duration. In the adjustable version, the addition of a capacitor, CFB, from the OUT pin to the FB pin will also improve the transient response.
The TPS737xx does not have active pulldown when the output is over-voltage. This architecture allows applications that connect higher voltage sources, such as alternate power supplies, to the output. This architecture also results in an output overshoot of several percent if the load current quickly drops to zero when a capacitor is connected to the output. The duration of overshoot can be reduced by adding a load resistor. The overshoot decays at a rate determined by output capacitor COUT and the internal/external load resistance. The rate of decay is given by:
(Fixed voltage version)
(Adjustable voltage version)