STEVAL-ISV006V1 STMicroelectronics, STEVAL-ISV006V1 Datasheet - Page 13

• Manufacturer Part Number: STEVAL-ISV006V1
• Description: IC LINEAR
• Manufacturer: STMicroelectronics

Specifications of STEVAL-ISV006V1

• Lead Free Status / Rohs Status: Lead free / RoHS Compliant
• Other names: 497-11418

AN3319
6
External component selection
SPV1040 requires a set of external components and their proper selection guarantees both
the best chip functionality and system efficiency.
Input voltage capacitor
Cin1 is the input capacitor connected to the input rail in order to reduce the voltage ripple.
According to the maximum current (Isc) provided by the PV panel connected at the input,
the following formula should be considered to select the proper capacitance value for a
specified maximum input voltage ripple (Vin_rp_max):
Maximum voltage of this capacitor is strictly dependent on the input source (typically
between 1 V and 3 V).
Low-ESR capacitors are a good choice to increase the whole system efficiency. In order to
reduce the ESR effect, it is suggested to split the input capacitance into two capacitors
placed in parallel.
Input voltage partitioning
V
Depending on the Voc of the PV panel, the V
rail (if Voc < 1.25 V) or biased through a resistor divider (R3 and R4) tied to PV+ rail.
In fact, V
proper MPP tracking. Consequently, the resistor divider must be identified according to the
following rule:
With regard to the V
●
●
R3 and R4 should be selected in the range of 100 kΩ - 10 MΩ to increase the system
efficiency.
Cin ≥
R
R
MPP-SET
3
4
=
When SPV1040 is OFF, V
When SPV1040 is in operating mode, it enters BURST MODE if V
triggering the 450 mV threshold.
Fsw
Vref
Voc
MPP-SET
is the pin used to monitor the voltage generated by the solar cells.
*
−
Vin
1
Isc
=
_
. 1
Voc
rp
is referred to as an internal voltage reference (Vref = 1.25 V) to allow
25
_
MPP-SET
max
−
1
pin, two more constraints must be taken into account:
Doc ID 18265 Rev 1
MPP-SET
voltage must be ≥0.3 to turn ON the device
MPP-SET
pin can be directly connected to PV+
External component selection
MPP-SET
decreases
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