EVALA5973AD STMicroelectronics, EVALA5973AD Datasheet - Page 10

• Manufacturer Part Number: EVALA5973AD
• Description: Power Management Modules & Development Tools EVAL BOARD A5973AD Auto Grade
• Manufacturer: STMicroelectronics
• Type: DC/DC Switching Converters, Regulators & Controllersr

Specifications of EVALA5973AD

• Input Voltage: 4.4 V to 36 V
• Output Voltage: 1.235 V to 35 V
• Board Size: 23 mm x 20 mm
• Product: Power Management Modules
• Supply Current: 2.5 A
• Dimensions: 23 mm x 20 mm
• For Use With/related Products: AN1518
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Additional features and protection
3.8
4
4.1
4.2
4.3
10/30
Thermal shutdown
The shutdown block generates a signal that turns OFF the power stage if the temperature of
the chip goes higher than a fixed internal threshold (150 °C). The sensing element of the
chip is very close to the PDMOS area, ensuring fast and accurate temperature detection. A
hysteresis of approximately 20 °C keeps the device from turning ON and OFF continuously.
Additional features and protection
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.
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
intervention will be set at:
Equation 1
Where R
R
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.
2
is between the feedback pin and ground.
1
is the resistor connected between the output voltage and the feedback pin, and
V
OVP
=
1.3
•
R
------------------- -
1
R
+
2
R
2
•
V
FB
(Figure
14), the OVP
AN1518