Power Architecture - refer word document
Power Architecture description:
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For stand alone testing, BQ25570 solar cell is replaced with 3.3V LDO at 1A rated current.
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Internal buck of BQ25570 is configured to source 1.8V to on board components like Sensors, Flash BLE etc. Total current comsumption at 1.8V rail is 20mA
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VSTOR (4.2V) is used to source two TPS62080 DC/DC onboard buck regulators 0.6V and 1V. Total current consumption of both buck regulators combined together is 30 to 50mA
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Jasmine IC is DNP and therefore both buck regulators are at no load condition.
Output of VSTOR (Solar Harvesting IC) is connected to x2 buck regulators - refer word doc
Voltage Regulator 1 (Currently the buck regulators are at No load condition)
Inductor Isat = 100mA
Iout = No Load condition
Voltage Regulator 2 (Currently the buck regulators are at No load condition)
Inductor Isat = 100mA
Iout = No Load condition
PROBLEM STATEMENT:
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With above design, we are facing a random behaviour at VSTOR pin. Initially, boards have 4.2V at VSTOR pin. After many power cycles, the VSTOR voltage drops to 2.5V.
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If TPS62080 input bypassed from VSTOR, then VSTOR is restored to 4.2V.
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Current consumed by both TPS62080 devices is 34mA at no Load condition. Not sure why buck regulators consume 34mA at not load condition.
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Inductor used for TPS62080 has 100mA Isat.
QUERIES:
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Is it right method to source external DC/DC buck regulators (TPS62080) from the VSTOR voltage of BQ25570? If yes, then what is the maximum load current it can source?
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Why 2A rated current inductor is mandatory for TPS62080 when operated at 10 to 50mA Load?