Active-semi ACT8865EVK1-305 Руководство пользователя - Страница 4

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Recommended Operating Conditions

The ACT8865EVK1-305 is designed for a 5V input voltage. The maximum operating voltage is determined by
the IC's maximum input voltage rating. The minimum operating voltages are determined by the buck converters'
minimum input voltage and by the LDOs' dropout voltages. Maximum currents are determined by the IC's CMI
settings, which can be changed via I2C after startup.
Parameter
Description
Vin
All buck and LDO input voltages
I
Maximum Buck REG1 load current
out1_max
I
Maximum Buck REG2 load current
out2_max
I
Maximum Buck REG3 load current
out3_max
I
Maximum LDO REG4 load current
out4_max
I
Maximum LDO REG5 load current
out5_max
I
Maximum LDO REG6 load current
out6_max
I
Maximum LDO REG7 load current
out7_max
EVK Operation

Measuring Output Voltage Ripple

To observe the output voltage ripple, place the oscilloscope probe across the output capacitor with the probe
ground lead connected to the negative (-) capacitor terminal and the probe tip placed at the positive (+) capacitor
terminal. Set the oscilloscope to ac，5mV/division, 1us/division time base, and 20MHz bandwidth.
A standard oscilloscope probe has a long wire ground clip. For high frequency measurements, this ground clip
picks up high frequency noise and injects it into the measured output ripple. Figure 4 shows an easy way to
measure the output ripple properly. It requires removing the oscilloscope probe sheath and wrapping an
unshielded wire around the oscilloscope probe as short as possible, the true ripple can be measured.
Innovative Power
TM
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is a trademark of Active-Semi.
ActiveSwitcher
Table 1. Recommended Operating Conditions
Figure 4–Measuring output voltage ripple
4
UG109
Rev 3.0, 25-Sep-2018
Min
Typ
Max
Unit
2.7
5
5.5
V
1.15
A
1.15
A
1.3
A
0.32
A
0.32
A
OFF
A
OFF
A