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Hi, TI support team
The customer confirms the operation by inputting Vbus after SMT and before MCU software writing.
(Are these tests suitable for verifying normal operation?)
Problems during operation are as follows.
[Condition]
- Battery is not connected.
- There is almost no load towards Vsys. (The system is not operating.)
[Symptom]
[regular product]
Vsys=4.2V
BAT=4.2V
TS_BIAS=periodic high waveform
VBUS=5V
REGN=5V
[Irregular product]
Vsys=3.7V
BAT=0V
TS_BIAS=0V
VBUS=5V
REGN=5V
QON=high
I will upload additional circuit diagrams as they become available.
Please review.
Thanks.
Regards,
MJ
Hi, Ning
I have further inquiries.
After the SMT of the product, we are testing to ensure that the charging operation is performed during the initial test.
Q. Basically, are the registers of the BQ25622 set to default? (Are only some of them set?)
If not, how should I proceed during the initial test?
We will share the relevant information regarding the problem you inquired above.
The applied application's system power is connected to VBAT.
(I am not using VSYS.)
In other words, it is a structure in which the system operates while the battery is connected and there is VBUS input.
In a board judged to be normal, if VBUS is input and the battery is connected, charging is performed and the system is operating with VBAT power.
[SW waveform]
In a board judged to be defective, VBUS is input and the battery is not charged even if the battery is connected. (VBAT=0V)
[SW waveform]
(It does not happen periodically.)
I suspected it was HI-Z mode, but when I checked the register, the register was set to 0.
As for the TS pin, NTC was not actually used, but HW setting was made through resistor distribution as shown below, and the normal and defective
settings are the same. However, in case of defects, it is recognized as high temp.
In case of normal product, high signal is generated periodically and Temp. is detected. (TS_BIAS power supply is present)
In the case of a defective product, the TS_BIAS power supply is 0V and the waveform that the TS pin checks periodically is not measured.
Which part is the problem?
This is an additional confirmation.
[Normal sample]
-INT : 2.5V
-CE : low
-STAT: low
-PG : low
[bad sample]
- INT: slow swing waveform
-CE : low
- STAT: slow swing waveform
- PG : slow swing waveform
- Waveform
Please let me know if there is anything else I need to check.
Please review.
Thanks.
Regards,
MJ
Hi, Ning
Thank you for your reply.
We checked part information register of several products.
We confirmed that REGx38[5:3] of abnormal products is 0h.
But top marking information of datasheet is different from actual items.
Can the top marking information of the two parts be verified for authenticity?
Please Check.
Thanks.
Regards,
MJ
