STEVAL-ISA052V1 STMicroelectronics, STEVAL-ISA052V1 Datasheet - Page 43

• Manufacturer Part Number: STEVAL-ISA052V1
• Description: KIT EVAL PM6675S HE CTLR 2A REG
• Manufacturer: STMicroelectronics

Specifications of STEVAL-ISA052V1

• Main Purpose: DC/DC, Step Down with LDO
• Outputs And Type: 2, Non-Isolated
• Voltage - Output: 1.5V, 0.6 ~ 3.3V
• Current - Output: 10A, 2A
• Voltage - Input: 4.5 ~ 28 V
• Regulator Topology: Buck
• Board Type: Fully Populated
• Utilized Ic / Part: PM6675
• Product: Power Management Modules
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Power - Output: -
• Frequency - Switching: -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant
• Other names: 497-8426

PM6675S
8.1.4
If ceramic capacitors are used, the output voltage ripple due to inductor current ripple is
negligible. Then the inductance should be smaller, reducing the size of the choke. In this
case it is important that output capacitor can adsorb the inductor energy without generating
an over-voltage condition when the system changes from a full load to a no load condition.
The minimum output capacitance can be chosen by the following equation:
Equation 39
where Vf is the output capacitor voltage after the load transient, while Vi is the output
capacitor voltage before the load transient.
In
Table 13.
MOSFETs selection
In a notebook application, power management efficiency is a high level requirement.
The power dissipation on the power switches becomes an important factor in the selection
of switches. Losses of high-side and low-side MOSFETs depend on their working condition.
Considering the high-side MOSFET, the power dissipation is calculated as:
Equation 40
Maximum conduction losses are approximately given by:
Equation 41
Table 13
Manufacturer
HITACHI
SANYO
are listed some tested polymer capacitors.
Evaluated output capacitors
TNCB OE227MTRYF
4TPE220MF
4TPE150MI
4TPC220M
Series
P
conduction
P
DHighSide
C
OUT
=
R
,
min
=
Capacitance
DSon
P
conduction
=
(µF)
220
220
220
220
L
⋅
Vf
V
⋅
V
I
IN
LOAD
OUT
2
.
min
−
+
Vi
,
MAX
P
⋅
I
2
switching
LOAD
Rated voltage
2
,
MAX
2.5 V
4 V
4 V
4 V
(V)
2
Application information
ESR max @100 kHz
15 to 25
(mΩ)
18
40
25
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