BQ25601: JEITA Thermistor spec duplication

user4369354

Part Number: BQ25601

Dear Sir,

NTC_FAULT changes frequently at the temperature where the rise and fall overlap in the temperature range of JEITA Thermistor.

For example, since 45.1% to 45.8% overlap in T3, NTC_FAULT changes frequently between Normal⇔Warm as shown below.
VT3_Rising: 43.8-45.8%
VT2_Falling: 45.1-46.2%

Does this behavior correct?

Best regards,
Chiaki Endo

over 5 years ago

0 user4369354 over 5 years ago

Expert 1220 points

I'm sorry.

"VT2_Falling: 45.1-46.2%" is wrong.

"VT3_Falling: 45.1-46.2%" is correct.

0 ezhao over 5 years ago in reply to user4369354

TI__Genius 10240 points

Chiaki,

The thresholds could have overlap for two different ICs in high volume samples. For one give IC, the two thresholds should not overlap. Do you have 4.7uF 10-V cap on REGN to get stable REGN voltage? How did you simulate the temperature change in your test?

0 user4369354 over 5 years ago in reply to ezhao

Expert 1220 points

Hi Eric,

Thank you for your reply.

I understood that VT3_Rising and VT3_Falling do not overlap in the same IC.

REGN has a 4.7uF 10V capacitor.

The test is conducted in a 40 ° C temperature chamber.

* The numerical value (%) of JEITA Thermistor Comparator was added to the graph Y axis.

Chiaki Endo

0 Joel Hernandez II over 5 years ago in reply to user4369354

TI__Mastermind 25800 points

Hey Chiaki,

How was the percentage captured? How do you sample the REGN pin voltage vs. the TS pin voltage?

Regards,

Joel H

0 user4369354 over 5 years ago in reply to Joel Hernandez II

Expert 1220 points

Hi Joel,

Thank you for your reply.

I sampled the REGN and TS pin voltages with a data logger (KEYENCE NR-600) and the percentage was calculated from the results.
Frequently changeing of NTC-FAULT disappeared when this data logger was disconnected.
It seems that the connection of the data logger was affected.

Regards,
Chiaki Endo

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BQ25601: JEITA Thermistor spec duplication