The TPS720 family of dual rail, low-dropout linear regulators (LDOs) offers outstanding
ac performance (PSRR, load and line transient response), while consuming a very low quiescent
current of 38 µA.
The VBIAS rail that powers the control circuit of the LDO draws
very low current (on the order of the quiescent current of the LDO) and can be connected to any
power supply that is equal to or greater than 1.4 V above the output voltage. The main power path
is through VIN, which can be a lower voltage than
VBIAS; it can be as low as VOUT +
VDO, increasing the efficiency of the solution in many power-sensitive
applications. For example, VIN can be an output of a high-efficiency, DC-DC
The TPS720 supports a novel feature in which the output of the LDO regulates under light
loads when the IN pin is left floating. The light-load drive current is sourced from
VBIAS under this condition. This feature is particularly useful in
power-saving applications where the DC-DC converter connected to the IN pin is disabled but the LDO
is still required to regulate the voltage to a light load.
The TPS720 is stable with ceramic capacitors and uses an advanced BICMOS fabrication
process that yields a dropout of 110 mV at a 350-mA output load. The TPS720 has the unique feature
of providing a monotonic VOUT rise (overshoot limited to 3%) with VIN inrush current limited
to 100 mA + ILOAD with an output capacitor of 2.2 µF.
The TPS720 uses a precision voltage reference and feedback loop to achieve overall
accuracy of 2% over load, line, process, and temperature extremes. An ultra-small DSBGA package
makes the TPS720 ideal for handheld applications. The TPS720 is also available in a SON-8 package.
This family of devices is fully specified over the temperature range of
TJ = –40°C to 125°C.