BQ27421-G1: BQ27421YZFR-G1A, Chip stops replying and acts like dead

George Kassiteropoulos

Part Number: BQ27421-G1

We are using your chip BQ27421YZFR-G1A. It has been working fine for a few weeks at a time or more. At some point the chip stops replying and acts like dead. Regardless of what we do it doesn't acknowledge back the I2C. And we basically cannot get any measurement. Our hardware engineers believe the chip might be getting into a shutdown mode. if we programmatically do unseal, SHUTDOWN_EN, SHUTDOWN, it behaves similarly. Is there a chance this chip can enter the shutdown mode by any other means rather than being forced to do so using software. Do you think there something that can be done wrong which could lead to the chip not acknowledging the I2C lines and essentially not working.

over 4 years ago

0 Jessica H. over 4 years ago

TI__Genius 11535 points

Hi George,

I'm trying to get a better understanding of what is happening. Could you measure the power consumption into the chip? Is the current at pin C3 closer to the shutdown current (typically .6uA) or one of the other supply current modes (typically >9uA)?

Best,

Jessica

0 George Kassiteropoulos over 4 years ago in reply to Jessica H.

Prodigy 115 points

Hello Jessica,

we have measured the consumption of our device in sleep mode. The current is 5.2mA.

At the same time, the consumption of the Gas Gauge chip ranges from 24 μA to 65 μA. This is when the chip works fine.

We will be able to measure the consumption when the connection with the chip was lost.

Voltage of 1.8V is present at pin B3 of the Gas Gauge.

0 Jessica H. over 4 years ago in reply to George Kassiteropoulos

TI__Genius 11535 points

Hi George,

I'm sorry for the delayed response. What is the power consumption after the I2C stops working? Does the current remain in the 24-65 uA range or does it drop down?

0 George Kassiteropoulos over 4 years ago in reply to Jessica H.

Prodigy 115 points

Hello Jessica,

As mentioned in my first post at some point the chip stops replying and acts like dead.

With that being said, at this specific time the chip works normally, but as soon as the chip stops responding again we will measure the current.

George

0 Kang Kang over 4 years ago in reply to George Kassiteropoulos

TI__Mastermind 24870 points

Hello George,

We will need some more clarifications when the chip is no longer communicating.

1. Can you measure the current consumption of the IC in this state? One other item to look at is VDD to GND.

2. Can you narrow down the window in which this is happening? We need to understand what happens prior to this event.

3. What are some of the things you have tried in order to reproduce this.

0 George Kassiteropoulos over 4 years ago in reply to Kang Kang

Prodigy 115 points

Hello Kang Kang,

We are closing this ticket because we think it is a software issue.

Power management

Power management forum

BQ27421-G1: BQ27421YZFR-G1A, Chip stops replying and acts like dead