L1806

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