TPS65185/about active discharge timing

Tsukui Yusuke

Guru 21930 points

Other Parts Discussed in Thread: TPS65185

Hi,

Could you tell me aboout TPS65185 active dischage timing?
When each output is OFF status,
Does this function will always discharge ON?

Also,
When each output start-up timing,
Dose this function will dischage ON?

Best regards,
Yusuke/Japan Disty

over 8 years ago

0 Tsukui Yusuke over 8 years ago

Guru 21930 points

Hi,

Can I get the information?

If you need more information or if I should clarify my comment ,

please let me know.
Customers want the information for the display design.
Please tell me about the timing of the active discharge.

I'm sorry to rush you.

Best regards,
Yusuke/Japan Disty

0 Richard Solarski over 7 years ago in reply to Tsukui Yusuke

TI__Genius 10885 points

Hi Yusuke-san,

The discharge delay is 100ms by default, but this is the amount of time the negative boost will be left active during shutdown while the other regulators discharge, and this timing is not a parameter that we test in production.

Active discharge behavior is further detailed in section 8.3.1 and 8.3.4 of the datasheet: www.ti.com/.../tps65185.pdf

If the regulators are connected to to the discharge pins they will be actively discharged once disabled, and this feature should not interfere with power-up sequencing.

0 Tsukui Yusuke over 7 years ago in reply to Richard Solarski

Guru 21930 points

Richard-san,

Thank you for your kind support.
I understand and I will report it to the customer.

Best regards,
Yusuke/Japan Disty

0 Tsukui Yusuke over 7 years ago in reply to Tsukui Yusuke

Guru 21930 points

Hi Richard-san,

Let me ask you one more thing.
Could you tell me discharge start timing?
Please tell me using the timing chart.

Best regards,
Yusuke/Japan Disty

0 Richard Solarski over 7 years ago in reply to Tsukui Yusuke

TI__Genius 10885 points

Hi Yusuke-san,

Within this timing diagram, it looks like the discharge delay is the 50ms from VB falling to VN rising, as this is the minimum discharge delay for this device, according to note 3 on Table 7-5 of the datasheet. However, by default, the discharge delay should be 100ms, according to the parametric table.

However, the individual regulators should actively discharge as soon as they are disabled. This delay is just an additional waiting period before VN is disabled.

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TPS65185/about active discharge timing