LR9103

DESCRIPTION 

The UTC LR9103 is a typical LDO (linear regulator) with the 

features of high output voltage accuracy, low supply current, low 

ON-resistance, and high ripple rejection. 

During operation of the UTC LR9103, the dropout voltage is 

very low and the response of line transient and load transient are 

very well. 

Internally, there’re many functions of UTC LR9103 which can 

be seen in the block figure. There are a voltage reference unit, an 

error amplifier, resistor-net for voltage setting, a current limit circuit, 

and a chip enable circuit in each UTC LR9103. 

The UTC LR9103 can be used as an ideal of the power supply 

for hand-held communication equipment, such as: power source for 

portable communication equipment, power source for electrical 

appliances, for example, cameras, VCRs and camcorders and 

power source for battery-powered equipment. 

FEATURES 

* Ultra Supply Current: 42µA (Typ.) 

* Standby Mode: 0.1µA (Typ.) 

* Very Low Dropout Voltage: 0.13V (Typ.) @ IOUT =150mA, VOUT =2.85V 

* Ripple Rejection: 65dB (Typ.) @ f=1kHz,VOUT=2.85V 

* Temperature-Drift Coefficient 

of Output Voltage: 

±50ppm/°C (Typ.) 

* Well Line Regulation: 0.05%/V (Typ.) 

*Output Voltage Accuracy: ±1.0% 

* Internal Fold Back Protection Circuit: 50mA (Typ.) (Current at short mode) 

*CIN=COUT=1.0µF or more (Ceramic capacitors) are recommended to be used with this IC