TLV62569A: Ref drift over -40 to 125

Takashi Onawa

Part Number: TLV62569A
Other Parts Discussed in Thread: TPS62821, TPS62810-Q1

Hi Team,

Ref variation at 25C is only specified on the datasheet.
Can we warrant Vref temp drift will be within 0.5% though -40C to 125C?

My customer wants to achieve 3% output accuracy on 3.3Vto1.5V@0.2A over full temp range.
But they can not make sure if the requirement is achievable with TLV62569A, since Vref variation is not specified by numbers(only showed by example plot in Fig.2).

Regards,

Takashi Onawa

over 4 years ago

0 Yann Ducommun over 4 years ago

TI__Intellectual 2605 points

Hi Takashi-san,

Correct, VFB is specified to +/- 2% at room temperature only for TLV62569A.

Therefore, it is not advisable to use this part if +/-3% output accuracy is needed over the full -40°C to 125°C temperature range.

Please check, for example, TPS62821, which features +/-1% VFB accuracy over full temperature range TJ = -40°C to 125°C.

Best regards,

Yann

0 Takashi Onawa over 4 years ago in reply to Yann Ducommun

TI__Genius 13200 points

Hi Yann-san,

Thanks for your suggestion and comment.

Regarding TPS62821, It doesn't have FPWM mode so that ripple in light load condition might be a little bit bigger.
How much ripple can be expected under light load in TPS62821?

Regards,

Takashi Onawa

0 Yann Ducommun over 4 years ago in reply to Takashi Onawa

TI__Intellectual 2605 points

Hi Takashi-san,

What are the ripple requirements of the application?

Figure 45 of the datasheet shows the typical ripple in PFM mode with 50mA load current.

Thanks and best regards,

Yann

0 Takashi Onawa over 4 years ago in reply to Yann Ducommun

TI__Genius 13200 points

Hi Yann-san,

30mV against 1V output for 3% DC output accuracy. So beyond 20mV ripple is not acceptable since Vref has 1% variation against temp range.
The load is estimated around 0.1 to 0.4A for 1.0V rail so I think the device which has FPWM mode is better for this socket.

Which device is suitable for the 3% output voltage accuracy in light load?

Regards,

Takashi Onawa

0 Yann Ducommun over 4 years ago in reply to Takashi Onawa

TI__Intellectual 2605 points

Hi Takashi-san,

Would adding a dummy load at the TPS62821 converter output to make it operate in PWM mode with lower ripple be acceptable in this application?

Thanks,

Yann

0 Takashi Onawa over 4 years ago in reply to Yann Ducommun

TI__Genius 13200 points

Hi Yann-san,

I don't think it works. Fundamentally, power limit of chip resister is not so big, estimated around 0.06W for 1005(mm) chip.
Considering 80% derating, it is possible to add 50mA load for one resister, so load threshold that does not enter PSM mode is controversial.

Do you have any data about the threshold to enter PSM mode?

Regards,

Takashi Onawa

0 Yann Ducommun over 4 years ago in reply to Takashi Onawa

TI__Intellectual 2605 points

Hi Takashi-san,

I will be out of office for a week. I'm assigning this thread to a colleague in order to ensure you get support while I'm out.

Thanks!

Yann

0 Sabrina over 4 years ago in reply to Takashi Onawa

TI__Expert 8420 points

Hi Takashi-san,

Let me check in our database if this information is available and get back to you later this week.

Just as additional information we have the TPS62810-Q1 that would fit your application requirements, however it is a performance optimized device therefor not in the same ball park as the TLVs

Regards,

Sabrina

0 Excel Regidor over 4 years ago in reply to Sabrina

TI__Mastermind 26736 points

Hi Takashi-san,

Apology for the late response.

Can you provide the parameters below so can check if we can provide the required resistor load to make the device operate at FPWM?

Best regards,

Excel

0 Excel Regidor over 4 years ago in reply to Excel Regidor

TI__Mastermind 26736 points

Hi Takashi-san,

If you don't have any further queries, then I will close this thread.

Best regards,

Excel

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TLV62569A: Ref drift over -40 to 125