EVALPM6680A STMicroelectronics, EVALPM6680A Datasheet - Page 33
EVALPM6680A
Manufacturer Part Number
EVALPM6680A
Description
EVAL BOARD FOR PM6680A
Manufacturer
STMicroelectronics
Datasheet
1.PM6680ATR.pdf
(48 pages)
Specifications of EVALPM6680A
Mfg Application Notes
PM6680A, AN2565 Appl Note
Main Purpose
DC/DC, Step Down with LDO
Outputs And Type
3, Non-Isolated
Power - Output
10.5W
Voltage - Output
1.8V, 3.3V, 5V
Current - Output
2.5A, 2.5A, 100mA
Voltage - Input
6 ~ 36V
Regulator Topology
Buck
Frequency - Switching
200kHz, 300kHz
Board Type
Fully Populated
Utilized Ic / Part
PM6680A
Lead Free Status / RoHS Status
Lead free / RoHS Compliant
Other names
497-6263
Available stocks
Company
Part Number
Manufacturer
Quantity
Price
PM6680A
9.5
Power MOSFETS
Logic-level MOSFETs are recommended, since low side and high side gate drivers are
powered by LDO5. Their breakdown voltage VBR
In notebook applications, power management efficiency is a high level requirement. The
power dissipation on the power switches becomes an important factor in switching
selections. Losses of high-side and low-side MOSFETs depend on their working conditions.
The power dissipation of the high-side MOSFET is given by:
Equation 18
Maximum conduction losses are approximately:
Equation 19
where RDSon is the drain-source on resistance of the high side MOSFET.
Switching losses are approximately:
Equation 20
where t
As general rule, high side MOSFETs with low gate charge are recommended, in order to
minimize driver losses.
Below there is a list of possible choices for the high side MOSFET.
Table 13.
The power dissipation of the low side MOSFET is given by:
Equation 21
Maximum conduction losses occur at the maximum input voltage:
Manufacturer
P
switching
on
and t
ST
High side MOSFET manufacturer
=
off
V
IN
are the switching times of the turn
×
I (
LOAD
STS5NF60L
P
conduction
(max)
Type
P
DHighSide
2
−
P
∆
=
2
DLowSide
I
R
L
)
DSon
=
×
P
t
on
conduction
×
Gate charge (nC)
=
×
V
V
P
f
IN
OUT
sw
conduction
min
DSS
+
25
+
×
on
V
P
I
IN
LOAD
must be higher than V
switching
and turn
×
I (
(max)
LOAD
(max)
off
2
Rated reverse voltage (V)
phases of the MOSFET.
2
+
∆
Design guidelines
2
I
L
)
×
INmax
60
t
off
×
.
f
sw
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