Original question:
Dear Expert
The STAT pin of the charging chip BQ24133 encounters the following problems:
When only the adapter is connected without the battery, the STAT level changes and the STAT pin LED flashes normally.
But sometimes, when the adapter is inserted without battery connection, the STAT level does not change and the LED of STAT pin does not light up. Please help us find the reason. thank you.
The circuit design of this part is as follows:
Dear Jeff
1.Once the battery is connected, the chip can charge the battery and work normally, except that sometimes the STAT does not blink when the battery is removed.
2.When STAT does not light,the voltages at REGN is 3.16V-4.9V,and the voltages at OVPSET is 1.24v-1.32V
the REGN waveform:
the OVPSET waveform:
3.When STAT lights,the voltages at REGN is 4.8V-4.9V,and the voltages at OVPSET is 1.24v-1.32V
the REGN waveform:
the OVPSET waveform:
4.When i place an oscope probe on SW(the STAT does not light), there is no square waveform
the SW waveform:
When i place an oscope probe on SW(the STAT lights)
the SW waveform:
