R5972D datasheet(12/35 Pages) STMICROELECTRONICS

номер детали	R5972D

подробное описание детали	Up to 1.5 A step-down switching regulator for aerospace applications

PDF	35 Pages

Scroll/Zoom	100%

производитель	STMICROELECTRONICS [STMicroelectronics]

домашняя страница	http://www.st.com

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12 / 35 page

Additional features and protection

R5972D

12/35

DocID026873 Rev 1

Additional features and protection

6.1

Feedback disconnection

If the feedback is disconnected, the duty cycle increases towards the maximum allowed

value, bringing the output voltage close to the input supply. This condition could destroy the

load.

To avoid this hazardous condition, the device is turned OFF if the feedback pin is left

floating.

6.2

Output overvoltage protection

Overvoltage protection, or OVP, is achieved by using an internal comparator connected to

the feedback, which turns OFF the power stage when the OVP threshold is reached. This

threshold is typically 30% higher than the feedback voltage.

When a voltage divider is required to adjust the output voltage (Figure 13 on page 24), the

OVP intervention will be set at:

Equation 1

Where R1 is the resistor connected between the output voltage and the feedback pin, and

R2 is between the feedback pin and ground.

6.3

Zero load

Due to the fact that the internal power is a PDMOS, no boostrap capacitor is required and so

the device works properly even with no load at the output. In this case it works in burst

mode, with a random burst repetition rate.

VOVP

1.3

R1 R2

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

VFB

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R5972D датащи(PDF) 12 Page - STMicroelectronics