UCC381屬于集成電路（IC）的ACDC轉(zhuǎn)換器離線開關(guān)。由美國德州儀器公司制造生產(chǎn)的UCC381AC DC 轉(zhuǎn)換器，離線開關(guān)該系列是元器件級控制產(chǎn)品，用于構(gòu)建將交流市電轉(zhuǎn)換為直流電（通常電壓大幅降低）的設(shè)備。集成和未集成系統(tǒng)主要開關(guān)元件的器件均包括在內(nèi)。由于高輸入輸出電壓比，以及此類系統(tǒng)中通常需要隔離，這些器件通常與外部變壓器配合使用。盡管通常使用定制變壓器來實(shí)現(xiàn)此用途，但也有許多專門用于此用途的庫存產(chǎn)品，請參見“開關(guān)轉(zhuǎn)換器，SMPS 變壓器”標(biāo)題。

FEATURES

? Precision Positive Linear Voltage

Regulation

? 0.5V Dropout at 1A

? Guaranteed Reverse Input/ Output

Voltage Isolation with Low Leakage

? Low Quiescent Current Irrespective of

Load

? Adjustable Output Voltage Version

? Fixed Versions for 3.3V and 5V

Outputs

? Logic Shutdown Capability

? Short Circuit Power Limit of

3% ? VIN ? Current Limit

? Remote Load Voltage for Accurate

Load Regulation

DESCRIPTION

The UCC381-3/-5/-ADJ family of positive linear series pass regulators is

tailored for low drop out applications where low quiescent power is important.

Fabricated with a BiCMOS technology ideally suited for low input to

output differential applications, the UCC381 will pass 1A while requiring

only 0.5V of input voltage headroom. Dropout voltage decreases linearly

with output current, so that dropout at 200mA is less than 100mV. Quiescent

current is always less than 650μA. To prevent reverse current conduction,

on-chip circuitry limits the minimum forward voltage to typically 50mV.

Once the forward voltage limit is reached, the input-output differential voltage

is maintained as the input voltage drops until undervoltage lockout disables

the regulator.

UCC381-3 and UCC381-5 versions have on-chip resistor networks preset

to regulate either 3.3V or 5.0V, respectively. Furthermore, remote sensing

of the load voltage is possible by connecting the VOUTS pin directly at the

load. The output voltage is then regulated to 1.5% at room temperature and

better than 2.5% over temperature. The UCC381-ADJ version has a regulated

output voltage programmed by an external user-definable resistor ratio.