BQ24193: Temperature settings for battery on TS pins

Aliasgar lightwala

Prodigy 50 points

Part Number: BQ24193

Datasheet specifies the below:

The resistor bias network has been updated as below.

RT2 = ((Vvref X RTHcold X RTHhot X (1/VT1 -1/VT5)) / ((RTHhot X (Vvref/VT5 -1) -RTHcold X (Vvref/VT1-1))

Select 0°C to 60°C range for Li-ion or Li-polymer battery,
RTHT1 = 27.28 kΩ
RTHT5 = 3.02 kΩ
RT1 = 2.27 kΩ
RT2 = 6.86 kΩ

Cool temperature is 0 to 10 degree C

Warm temperature is 45 to 60 degree C

Information needed.

1.What is the value of Vvref?

2. What is the temperature range for COLD & HOT?

3.How RTHT1 and RTHT5 is derived?

4.What is the value for RTHHOT AND RTHCOLD to calculate RT1 and RT2 respectively.

I am planning to test the temperature change by changing the value of the Resistor RT1 and RT2 ,howerver there are somany unknowns(mentioned above).

Iam confused, kindly help!

Best regards,

Ali

over 3 years ago

0 Nick Brylski over 3 years ago

TI__Mastermind 19195 points

Hello Ali,

Vref is the pullup for NTC bias resistors, must be VREGN -- see EC table, JEITA THERMISTER COMPARATOR
You can adjust the range to what is required by your application.
Refer to the datasheet for your selected NTC
RTHHOT = RTHT5, RTHCOLD = RTHT1

We have a calculation tool you can refer to here: www.ti.com/.../slvrbe3

Best regards,

Nick

0 Aliasgar lightwala over 3 years ago in reply to Nick Brylski

Prodigy 50 points

Thank you nick. i will look into the tool

0 Aliasgar lightwala over 3 years ago in reply to Aliasgar lightwala

Prodigy 50 points

hello nick,

i have one more question.

What should be the charge termination current set?

if we set the default 256mA(it takes more time to charge), we have single cell 10000mAh battery.

Can you suggest what should be the thumb rule for charge termination current.?

Note: Charging current is set to 3Amps.

If increasing the charge termination current, will the battery be fully charged?

Kindly help.

Regards,

Ali

0 Nick Brylski over 3 years ago in reply to Aliasgar lightwala

TI__Mastermind 19195 points

Hi Ali,

The lower you set the termination current the more fully charged the battery will be. Lower termination currents will take a longer time to finished charging. The battery datasheet may have some info on this. Many of our devices have termination set to 10% of fast charging current by default but increases the termination current is OK to do.

Best regards,

Nick

0 Aliasgar lightwala over 3 years ago in reply to Nick Brylski

Prodigy 50 points

Thank you nick

0 Aliasgar lightwala over 3 years ago in reply to Aliasgar lightwala

Prodigy 50 points

hello nick

i have one more query below:

In the datasheet: Recommended operating conditions states:

ISYS: Output current = 4.5A

Fast charging current= 4.5A

Does the charger IC can deliver both the currents at the same time, meaning it can Charge with 4.5Amps as well it can source 4.5amps to the load?

I believe charging current will reduce with increase in the load current.

kindly correct me here if am wrong.

Regards,

Ali

0 Nick Brylski over 3 years ago in reply to Aliasgar lightwala

TI__Mastermind 19195 points

Hi Ali,

ISYS is combined charging plus load current on SYS. So if charging at 4.5A we do not recommend have any load on SYS.

For future questions we ask that you make a new post as the original issue has been resolved.

Best regards,

Nick

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BQ24193: Temperature settings for battery on TS pins