EVALA5972D STMicroelectronics, EVALA5972D Datasheet - Page 20

• Manufacturer Part Number: EVALA5972D
• Description: Power Management Modules & Development Tools EVAL BOARD A5972 Auto Grade
• Manufacturer: STMicroelectronics
• Type: DC/DC Switching Converters, Regulators & Controllersr

Specifications of EVALA5972D

• 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 A
• Dimensions: 23 mm x 20 mm
• For Use With/related Products: AN1517
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Application information
5.4
20/29
Considering that the device in SO-8 (4+2+2) package mounted on board with a good
groundplane has a thermal resistance junction to ambient (Rth
considering an ambient temperature of about 70 °C.
Equation 26
Short-circuit protection
In over-current protection mode, when the peak current reaches the current limit, the device
reduces the T
frequency to approximately one third of its nominal value (see
protection). In these conditions, the duty cycle is strongly reduced and, in most applications,
this is enough to limit the current to I
output (V
effect of external components), the current peak could reach values higher than I
This can be understood considering the inductor current ripple during the ON and OFF
phases:
●
Equation 27
●
Equation 28
where V
inductor.
In short-circuit conditions V
inductor is very small and it may be that the current ripple in this phase does not
compensate for the current ripple during the T
The maximum current peak can be easily measured through the inductor with V
(short-circuit) and V
circuit condition for an extended period, the external components (mainly the inductor and
diode) must be selected based on this value.
ON phase
OFF phase
D
OUT
is the voltage drop across the diode, and DCR
=0 V) and depending on the application conditions (V
ON
down to its minimum value (approximately 250 ns) and the switching
CC
=V
IN
∆
max. In cases where the application must sustain the short-
OUT
∆
I L
I
L
=
=
is negligible. So, during the T
T
(
----------------------------------------------------------------- -
(
-------------------------------------------------------------------- -
V D
J
V
IN
=
LIM
+
70
–
V out
. In any event, in case of heavy short-circuit at the
V
+
out
0.9 62
L
+
L
–
DCR L
ON
•
DCR
.
≅
L
128°C
I •
•
I
)
)
L
•
•
is the series resistance of the
T OFF
T
OFF
ON
Section 2.4: Current
J-A
, the voltage applied to the
) of about 62 °C/W and
CC
value and parasitic
OUT
LIM
AN1517
.
= 0 V