Product Description

Description

The LD4275 is a monolithic integrated low-drop voltage regulator in a 5 pin TO-package. An input voltage up to 45 V is regulated to VQ,nom = 5.0 V. The IC is able to drive loads up to 450 mA and is short-circuit proof. At over temperature the LD4275 is turned off by the incorporated temperature protection. A reset signal is generated for an output voltage VQ,rt of type. 4.65 V. The delay time can be programmed by the.external delay capacitor.

Features

Dimension Information on External Components

The input capacitor CI is necessary for compensation of line influences. Using a resistor of approx. 1in series with CI, the oscillating of input inductivity and input capacitance can be damped. The output capacitor CQ is necessary for the stability of the regulation circuit. Stability is guaranteed at values CQ 22 µF and an ESR of 5 within the operating temperature range.

Circuit Description

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 via a buffer. Saturation control as a function of the load current prevents any over saturation of the power element. The IC also incorporates a number of internal circuits for protection against: