STEVAL-PSQ001V1 STMicroelectronics, STEVAL-PSQ001V1 Datasheet - Page 31

• Manufacturer Part Number: STEVAL-PSQ001V1
• Description: BOARD EVAL BASED ON PM6680A
• Manufacturer: STMicroelectronics
• Type: Other Power Managementr

Specifications of STEVAL-PSQ001V1

• Design Resources: STEVAL-PSQ001V1 Gerber Files STEVAL-PSQ001V1 Schematic STEVAL-PSQ001V1 Bill of Material
• Main Purpose: DC/DC, Step Down with LDO
• Outputs And Type: 6, Non-Isolated
• Voltage - Output: 0.9 ~ 2.5 V, 1 ~ 3.3 V, 2x 3.3 V, 2.5 V, 5 V
• Current - Output: 4A, 2A, 800mA, 400mA, 400mA, 150mA
• Voltage - Input: 5 ~ 36V
• Regulator Topology: Buck
• Frequency - Switching: 200kHz, 300kHz
• Board Type: Fully Populated
• Utilized Ic / Part: PM6680A
• Input Voltage: 5 V to 36 V
• Output Voltage: 1 V to 3.3 V
• Product: Power Management Modules
• Silicon Manufacturer: ST Micro
• Silicon Core Number: PM6680A
• Kit Application Type: Power Management
• Application Sub Type: Power Supply
• Kit Contents: Board
• Rohs Compliant: Yes
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Power - Output: -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant
• For Use With/related Products: PM6680A
• Other names: 497-6425; STEVAL-PSQ001V1

PM6680A
9.3
Equation 14
If hard saturation inductors are used, the inductor saturation current should be much greater
than the maximum inductor peak current Ipeak:
Equation 15
Using soft saturation inductors it's possible to choose inductors with saturation current limit
nearly to Ipeak.
Below there is a list of some inductor manufacturers.
Table 10.
Output capacitor
The selection of the output capacitor is based on the ESR value Rout and the voltage rating
rather than on the capacitor value Cout.
The output capacitor has to satisfy the output voltage ripple requirements. Lower inductor
value can reduce the size of the choke but increases the inductor current ripple ∆IL.
Since the voltage ripple V
Equation 16
A low ESR capacitor is required to reduce the output voltage ripple. Switching sections can
work correctly even with 20 mV output ripple.
However, to reduce jitter noise between the two switching sections it's preferable to work
with an output voltage ripple greater than 30 mV. If lower output ripple is required, a further
compensation network is needed (see Closing the integrator loop paragraph).
Finally the output capacitor choice deeply impacts on the load transient response (see Load
transient response paragraph). Below there is a list of some capacitor manufacturers.
Manufacturer
COILCRAFT
COILCRAFT
WURTH
Inductor manufacturer
MSS1038
MSS7341
Series
TPC
RIPPLEout
∆
I
Ipeak
L
(max)
Inductor value
is given by:
V
RIPPLEout
=
1 to 22 µH
=
1.5 to 22
3.3 to 22
I
LOAD
(uH)
V
IN
max
(max)
f
sw
=
−
R
×
V
L
out
+
OUT
×
∆
I
∆
L
×
RMS current
I
(max)
L
2.85 to 7.85
2
1.7 to 3.95
V
V
2.7 to 8
IN
OUT
max
(A)
Design guidelines
Saturation current
2.9 to 8.30
1.3 to 3.5
2.6 to 9.5
(A)
31/48