SLUS215 - OCTOBER 1998

FEATURES

• Precision Positive Series Pass

Voltage Regulation

• 0.45V Dropout at 3A

• 50mV Dropout at 10mA

• Quiescent Current Under

650µA Irrespective of Load

• Adjustable (5 Lead) Output

Voltage Version

• Fixed (3 Lead) Versions for

3.3V and 5V Outputs

• Logic Shutdown Capability

• Short Circuit Power Limit of

3%

Leakage

• Thermal Shutdown

DESCRIPTION

The UCC283-3/-5/-ADJ family of positive linear series pass regulators are 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 applica-

tions, the UCC283-5 will pass 3A while requiring only 0.45V of typical input voltage

headroom (guaranteed 0.6V dropout). These regulators include reverse voltage

sensing that prevents current in the reverse direction. Quiescent current is always

less than 650

µA. These devices have been internally compensated in such a man-

ner that the need for a minimum output capacitor has been eliminated.

UCC283-3 and UCC283-5 versions are in 3 lead packages and have preset outputs

at 3.3V and 5.0V respectively. The output voltage is regulated to 1.5% at room tem-

perature. The UCC283-ADJ version, in a 5 lead package, regulates the output volt-

age programmed by an external resistor ratio.

Short circuit current is internally limited. The device responds to a sustained over-

tion during short circuit and means heat sinks need only accommodate normal op-

adjustable 5 leaded versions an external capacitor sets the on time — the off time

sions also serves as a shutdown input when pulled low.

Internal power dissipation is further controlled with thermal overload protection cir-

cuitry. Thermal shutdown occurs if the junction temperature exceeds 165°C. The

chip will remain off until the temperature has dropped 20°C.

The UCC283 series is specified for operation over the industrial range of

−40°Cto

+85°C, and the UCC383 series is specified from 0°C to +70°C. These devices are

available in 3 and 5 pin TO-220 and TO-263 power packages.

UCC283-3/-5/-ADJ

UCC383-3/-5/-ADJ

Low Dropout 3 Ampere Linear Regulator Family

BLOCK DIAGRAM

UDG-98133