STEVAL-PSQ001V1 STMicroelectronics, STEVAL-PSQ001V1 Datasheet - Page 40
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STEVAL-PSQ001V1
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
STEVAL-PSQ001V1
Design guidelines
9.8
40/48
Figure 40. Bootstrap circuit
The bootstrap circuit capacitor value C
side MOSFET during turn on phase. A typical value is 100 nF.
The bootstrap diode D must charge the capacitor during the off time phases. The maximum
rated voltage must be higher than V
A resistor R
node rises up, working like a gate resistor for the turn on phase of the high side MOSFET.
Design example
The following design example considers an input voltage from 16 V to 32 V(the typical value
is 24 V). The two switching outputs are OUT1 = 3.3 V and OUT2 = 1.8 V and must deliver a
maximum current of 2.5 A. The selected switching frequencies are about 290 kHz for OUT1
section and about 440 kHz for OUT2 section (see
1.
OUT1: ILOAD = 2.5 A, 45 % ripple current.
Equation 36
We choose standard value L= 8.2 µH.
∆I
I
I
OUT2:ILOAD=2.5 A, 35 % ripple current.
LRMS
peak
L(max)
Inductor selection
= 2.5 A + 0.58 A = 3.83 A
= 2.523 A
= 1.16 A @VIN = 24 V.
BOOT
on the BOOT pin could be added in order to reduce noise when the phase
L
L
INmax
BOOT
C
C
.
R
R
B
B
O
B
B
O
must provide the total gate charge to the high
O
O
O
O
O
O
T
T
D
D
T
T
B
P
B
P
Table 6
O
H
H
O
L
L
A
A
O
O
D
D
S
S
T
T
O
O
E
E
5
5
).
PM6680A