TPS61196: Power sequence of TPS61196

takahiko yokota

Mastermind 7135 points

Part Number: TPS61196

I get the questions from my customer.

Are there the problems to start up PWM before starting up EN?

Are there the rule about power down sequence?

Best regards,

Yokota

over 6 years ago

0 Sean Zhou over 6 years ago

TI__Mastermind 22745 points

Hi Takahiko,
(1). It's ok to start up PWM signal before starting up EN, If the PWM
dimming signals come before the EN signal is high, the soft start-up begins immediately after the detection of
unused channels.
(2). There is no rules for power down sequence.
Best Regards
Sean

0 takahiko yokota over 6 years ago in reply to Sean Zhou

Mastermind 7135 points

Hi Sean-san

Thank you for the reply.

Please let me confirm just in case.

I understood the power up sequence is the following if EN is high after input PWM signal.

Is my understanding correct?

1. Input PWM signal

2. EN High

3. Start-up VDD

4.Unused channel detection

5. Start-up Soft start

Best regards,

Yokota

0 Sean Zhou over 6 years ago in reply to takahiko yokota

TI__Mastermind 22745 points

Hi Takahiko,

VDD is internal LDO, you don't need to start up VDD. The power up sequence should be following if EN is high after input PWM signal:
1. Vin power on;
2.Input PWM signal;
3.EN set high;
4.Unused channel detection;
5. Start-up soft start;

Best Regards
Sean

0 takahiko yokota over 6 years ago in reply to Sean Zhou

Mastermind 7135 points

Hi Sean-san

Thank you for the reply.
Is it ok that VDD doesn't start up if EN is high after input PWM?

Best regards,
Yokota

0 Sean Zhou over 6 years ago in reply to takahiko yokota

TI__Mastermind 22745 points

Hi ,
VDD is the internal LDO, when you power the VIn, VDD will start up immediately. So don't worry about VDD.
Sean

0 takahiko yokota over 6 years ago in reply to Sean Zhou

Mastermind 7135 points

Hi Sean-san

I got a question from my customer.
I apologize for keep asking but it is written that VDD start after high EN in "7.3.1 Supply Voltage" of datasheet.
If EN is high after input PWM signal, are there possible outputed VDD even EN is low?

Best regards,
Yokota

0 Sean Zhou over 6 years ago in reply to takahiko yokota

TI__Mastermind 22745 points

Hi Yokota,

Yes, you are right. I'm sorry for the wrong reply. The power up sequence should be following if EN is high after input PWM signal:
1. Vin power on;
2.Input PWM signal;
3.EN set high;
4.VDD Start up
4.Unused channel detection;
5. Start-up soft start;

Best Regards
Sean

Power management

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TPS61196: Power sequence of TPS61196