AWRL1432: Noise and Ripple Specifications

Jimmy Gong

Part Number: AWRL1432
Other Parts Discussed in Thread: TPS628502,

Hi team,

I have a question here.

at normal situation we will use two tps628502, one for 3,3Vin and another is for 1,8Vin. tps629501 for 1.2Vin as below picture.

And I notice the datasheet of AWRL1432 Noise and Ripple Specifications show at 2000kHz, 1.8V's ripple need to meet 0.153mVp-p. this is very small value for buck. so I'm confused.

then I search tps628502 datasheet show that at 2.25MHz the condition is same as normal situation. However, The Vout ripple is around 8mVp-p higher than 0.153mVp-p AWRL1432 ripple specifications.

Could you please tell me where I am misunderstanding?

BR,

Jimmy

over 2 years ago

0 Abhed Misra over 2 years ago

TI__Genius 13805 points

Hi Jimmy,

Typically the dc-dc and device would have 1 or 2 stage filters in place, that also helps with reducing the output ripple form dc-dc.

Regards

0 Jimmy Gong over 2 years ago in reply to Abhed Misra

TI__Expert 3600 points

Hi Abhed,

Agree with you. However, that will be hard to select the buck solution within this 0.153mVp-p follow AWRL1432 spec. Do we have other idea can check this situation? otherwise, We can only choose other part numbers according to tps628502.

BR,

Jimmy

+1 Abhed Misra over 2 years ago in reply to Jimmy Gong

TI__Genius 13805 points

Hi Jimmy,

I agree, however, with some other means the output ripple can be reduced from dc-dc. Like putting filters, or adding a small series resistance, etc.

Otherwise LDO appraoch can also be selected.

Regards

0 Jimmy Gong over 2 years ago in reply to Abhed Misra

TI__Expert 3600 points

Hi Abhed,

Got it. thanks for your information.

Since my customer would like to use PMIC LP8752x-Q1 to provide the power to AWRL1432 to reduce BOM. I just would like to double check LP8752x-Q1 can be used at this situation. As I know that AWRL1432 will need 3 rail 3.3V, 1.8V and 1.2V. we can use LP87523-Q1 (2-phase+1 phase+1phase) totally 3 output voltage level to supply it.

If you have heard about the usage of this PMIC on AWRL1432. please let me know. thanks again.

BR,

Jimmy

0 Abhed Misra over 2 years ago in reply to Jimmy Gong

TI__Genius 13805 points

Hi Jimmy,

Usage of PMIC with 60 Lo/70 Lo devices is not common. However, there are cases where these PMIC's are being used.

Regards

0 Jimmy Gong over 2 years ago in reply to Abhed Misra

TI__Expert 3600 points

Pretty thanks for your information Abhed!

BR,

Jimmy

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AWRL1432: Noise and Ripple Specifications