ULE4275

DESCRIPTION 

   The UTC ULE4275 is a monolithic integrated low-dropout 

voltage regulator. The device regulates an input voltage up to 

45V to VOUT = 5V (typical). The device can drive loads up to 

450mA. It also provides overcurrent protection and 

overtemperature protection for control of the state of the output 

voltage. The device generates a reset signal for an output 

voltage, VOUT,rt, of 4.65V (typical). By the use of an external delay 

capacitor, one can program the reset delay time. 

The input capacitor, CIN, compensates for line fluctuation. 

Using a resistor of approximately 1Ω in series with CIN dampens 

the oscillation of input inductance and input capacitance. The 

output capacitor, COUT, stabilizes the regulation circuit. The 

specification for stability is at COUT ≥ 22μF and ESR ≤ 5Ω, within

the operating temperature range. Stability for electrolytic capacitors 

specifically is at COUT ≥ 68µF within the operating temperature range. 

   The control amplifier compares a reference voltage to a voltage that is 

proportional to the output voltage and drives the base of the series 

transistor through a buffer. Saturation control as a function of the load 

current prevents any oversaturation of the power element. The device 

also incorporates a number of internal circuits for protection 

against: overload, overtemperature, and reverse polarity. 

FEATURES

* Qualified for Automotive Applications 

* Output Voltage 5V ± 2% 

* Very Low Current Consumption 

* Power-On and Undervoltage Reset 

* Reset Low-Level Output Voltage<1V 

* Very Low Dropout Voltage 

* Internal Short-Circuit Current Limiting 

* Reverse-Polarity Proof