STEVAL-ISV009V1 STMicroelectronics, STEVAL-ISV009V1 Datasheet - Page 36

• Manufacturer Part Number: STEVAL-ISV009V1
• Description: Power Management Modules & Development Tools DUAL STG DC/AC CNVRT DEMO BRD
• Manufacturer: STMicroelectronics
• Series: -r

Specifications of STEVAL-ISV009V1

• Design Resources: STEVAL-ISV009V1 BOM STEVAL-ISV009V1 Schematic
• Main Purpose: DC/DC, Step Up
• Outputs And Type: 1, Non-Isolated
• Power - Output: -
• Voltage - Output: 36V
• Current - Output: -
• Voltage - Input: -
• Regulator Topology: Boost
• Frequency - Switching: -
• Board Type: Fully Populated
• Utilized Ic / Part: SPV1020
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

External component selection
13.10
Note:
13.11
13.12
36/52
Output voltage sensing capacitor
C10 is placed in parallel to R4 and as close as possible to pin Vout_sns.
Its role is to make as stable as possible the voltage sensed by pin Vout_sns.
Maximum Voltage: if R3 and R4 have been chosen properly, so partitioning Vout to 1.25 V,
then maximum voltage of this capacitor can be in the range from 3.3 V or higher.
Capacitance value depends on the time constant (τ
and by the system switching frequency (F
Assuming R4<<R3 (so, R3//R4
So,
Even if SPV1020 controls each phase at F
switching frequency (F
frequency (by default 400 kHz).
Internal oscillator frequency
SPV1020 controls the boost application by a PWM signal acting at the default switching
frequency of 100 kHz.
Default switching frequency is guaranteed connecting the pin OSCIN to 5 V (VREG pin).
User can change the default value by placing a proper resistor (R6) versus ground.
Internal oscillator works with an integrated resistor of 120 kΩ. Frequency is proportional to
the current provided to the oscillator block.
Said F
formula:
Diodes selection
SPV1020 requires 3 Schottky diodes: D1, D2 and D3.
D3 (with C11) protects the SPV1020 supply by noise of the whole system switching.
switch
the desired switching frequency, R7 must be selected according to the following
SSW
) must be assumed at 4 times the single phase switching
Doc ID XXXXX Rev 1
≅
R
C
R4):
[ 7
10
τ
k
o
Ω
≅
ut
]
10
≅
SSW
=
SW
10
∗
(
100
F
Fssw
(by default 100 kHz) the whole system
= 4*F
∗
sw itch
1
Fssw
)
1
out
∗
[
SW)
*
kHz
(
120
) composed with R4 (τ
R
1
.
4
]
)
out
= C8*R3//R4)
AN3392