STEVAL-ISV008V1 STMicroelectronics, STEVAL-ISV008V1 Datasheet - Page 10

• Manufacturer Part Number: STEVAL-ISV008V1
• Description: IC LINEAR
• Manufacturer: STMicroelectronics
• Series: -r

Specifications of STEVAL-ISV008V1

• Design Resources: STEVAL-ISV008V1 Schematic STEVAL-ISV008V1 BOM
• Main Purpose: Special Purpose DC/DC, Photovoltaic
• Outputs And Type: 3, Isolated
• Power - Output: 300W
• Voltage - Output: -
• Current - Output: -
• Voltage - Input: 0 ~ 40 V
• Regulator Topology: Boost
• Frequency - Switching: 100kHz
• Board Type: Fully Populated
• Utilized Ic / Part: SPV1020
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant
• Other names: 497-11419

Detailed description
5.4
Note:
5.5
10/18
Output voltage sensing and over voltage protection ovp
Another monitor is made on VOUT with VOUT_SNS pin. This pin is used to monitor the
output voltage in order to regulate the maximum value (which cannot exceed 40 V)
preventing damaging due to over voltage.
VOUT_SNS (partition of VOUT) is checked with a threshold, 1.0 V, generated by an internal
regulated voltage. When VOUT_SNS reaches 1V the output feedback loop enters regulation
limiting the output voltage.
The stability of the loop can be externally regulated connecting a resistor and a capacitor
(pole-zero compensation) between the PZ_OUT pin and SGND pin.
If VOUT_SNS exceeds 1.04V a fault signal is generated and transmitted to the fault
controller. This one stops the drivers and produces a fault to external chip (DIAG = 0).
When VOUT_SNS goes back down to 1.04 V the DC-DC goes ON again and the converter
is restarts the MPP research from the minimum duty cycle (5%).
Referring to the schematic showed in Application circuit, R3 and R4 are the 2 resistors used
for partitioning the output voltage.
Said VOUT_MAX the maximum output voltage of the load, the R3 and R4 must be selected
according to the following rule:
Also, in order to optimize the efficiency of the whole system, when selecting R3 and R4,
their power dissipation has to be taken into account.
Assuming negligible the current flowing through pin Vout_sns, maximum power dissipation
on the series R3+R4 is:
As empiric rule, R3 and R4 should be selected according to:
In order to guarantee the proper functionality of pin V
R3+R4 should be in the range between 20 µA and 100 µA.
Over current protection OCP
To guarantee a safe operation the low side power switches have an over current protection.
Indeed, when Lx is accidentally shorted to VIN or VOUT or when the current flowing through
the inductor exceed the current limit (~4.5 A), the related low side power switch is
immediately turned OFF and the linked synchronous rectifier is enabled to turn ON. The low
side power switch is turned ON again at the next PWM cycle.
P
vout
Doc ID 17588 Rev 2
_
P
sns
vout
R
R
<<
3
4
_
.
01
sns
=
x
V
=
V (
out
. 1
V (
out
02
R
_
out
max
_
3
max
+
_
max
R
out_sns
4
I
)
out
2
_
max
current flowing on the series
)
SPV1020