STEVAL-ISA051V1 STMicroelectronics, STEVAL-ISA051V1 Datasheet - Page 44

• Manufacturer Part Number: STEVAL-ISA051V1
• Description: BOARD EVAL PM6670S DDR2/3
• Manufacturer: STMicroelectronics
• Type: DC/DC Switching Converters, Regulators & Controllersr

Specifications of STEVAL-ISA051V1

• Design Resources: STEVAL-ISA051V1 Gerber Files STEVAL-ISA051V1 Schematic STEVAL-ISA051V1 Bill of Material
• Main Purpose: Special Purpose DC/DC, DDR Memory Supply
• Outputs And Type: 4, Non-Isolated
• Voltage - Output: 1.5V, 1.8V
• Voltage - Input: 4.5 ~ 28V
• Regulator Topology: Buck
• Board Type: Fully Populated
• Utilized Ic / Part: PM6670
• Input Voltage: 4.5 V to 28 V
• Output Voltage: 1.8 V, 1.5 V
• Product: Power Management Modules
• Silicon Manufacturer: ST Micro
• Silicon Core Number: PM6670S
• Kit Application Type: Power Management
• Application Sub Type: DDR2/3 Memory Power Supply Controller
• Kit Contents: Board
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Current - Output: -
• Power - Output: -
• Frequency - Switching: -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant
• For Use With/related Products: PM6670S
• Other names: 497-8411

Application information
8.1.4
44/54
If ceramic capacitors are used, the output voltage ripple due to inductor current ripple is
negligible. Then the inductance could 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 38
where Vf is the output capacitor voltage after the load transient, while V
capacitor voltage before the load transient.
In
Table 15.
MOSFETs selection
In a notebook application, power management efficiency is a high level requirement. 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 39
Maximum conduction losses are approximately given by:
Equation 40
Table 15
Manufacturer
HITACHI
SANYO
are listed some tested polymer capacitors are listed.
Evaluated output capacitors
TNCB OE227MTRYF
4TPE220MF
4TPE150MI
4TPC220M
Series
P
conduction
P
Doc ID 14432 Rev 4
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
2.5V
(V)
4V
4V
4V
2
I
ESR max @100 kHz
is the output
15 to 25
(mΩ)
25
18
40
PM6670S