DESCRIPTION

The UTC L1806 is a typical LDO with the features of very low

dropout voltage as low as 0.23V at output current 3A.

For normal operation, two supply voltages are necessary. One

called control voltage from other equipment can shutdown the

output voltage and it should pull and hold the voltage of EN pin less

than 0.5V. Another one is the main supply voltage whose purpose is

for main power conversion, to keep the power dissipation low, and

to make the dropout voltage lower.

Internally, in the UTC  L1806, there’re many functions which

can be seen in the block figure to prevent the IC from being

damaged. Internal Power-On-Reset (POR) circuit can control the

two supply voltages to prevent fault operations of the circuit; the

thermal shutdown circuit is able  to protect the device from over

thermal operation, and a current  limit function will keep the device

work safely under current over-loads.  

The UTC L1806 can be used as an ideal to provide well supply

voltage in the applications, such as front-side-bus termination on

motherboard, NB applications, front side bus VTT (1.2V/3A) and

note book PC applications.

FEATURES

* Low Dropout VD=0.23V(typ.)@ IOUT=3A

* Low ESR Output Capacitor  

* VREF=0.8V 

* Fast Transient Response

* Output Voltage Adjustable through External Resistors

* POR(Power-On-Reset) controlling VCNTL and VIN

* With internal Soft-Start

* Internal Current Limit Protection

* Internal Under Voltage Protection

* Hysteretic Thermal Shutdown

* With Power-OK Output (with a Delay Time)

* Low Shutdown Quiescent Current (<30 uA)

* Shutdown/Enable Control Function