1 Features

1• 350-mA High-Performance LDO

• Low Quiescent Current: 38 μA

• Excellent Load Transient Response:

±15 mV for ILOAD = 0 mA to 350 mA in 1 μs

• Excellent Line Transient Response:

ΔVOUT = ±2 mV for ΔVBIAS = ±600 mV in 1 μs

ΔVOUT = ±200 μV for ΔVIN = ±400 mV in 1 μs

• Low Noise: 48 μVRMS (10 Hz to 100 kHz)

• 80 dB VIN PSRR (10 Hz to 10 kHz)

• 70 dB VBIAS PSRR (10 Hz to 10 kHz)

• Fast Start-Up Time: 140 μs

• Built-In Soft-Start With Monotonic VOUT Rise and

Start-Up Current Limited to 100 mA + ILOAD

• Overcurrent and Thermal Protection

• Low Dropout: 110 mV at ILOAD = 350 mA

• Stable with 2.2-μF Output Capacitor

• Available in 1.33 mm × 0.96 mm DSBGA-5 and 2

mm × 2 mm SON-6 Packages

2 Applications

• Digital Cameras

• Cellular Camera Phones

• Wireless LAN

• Handheld Products

3 Description

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 step-down regulator.

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.