AM4372: Ferrite beads on power supplies

Sh.Sasaki

Guru 13625 points

Part Number: AM4372

Hi all,

Looking at the following circuit, several ferrite beads are connected to AM 437x Starter Kit board.

Why is this ferrite bead connected?

If this FB is protecting the power side of V 1_8D from voltage drop due to power consumption of AM4372,

my customer wants to consider deletion because there is no other IC using this power supply besides AM4372.

Best regards,

Sasaki

over 7 years ago

0 Biser Gatchev-XID over 7 years ago

TI__Guru**** 393215 points

Hi,

Please read section 5.13.2.1.1 of the AM437x Datasheet Rev. D. The ferrite beads form low-pass LC filters with the decoupling capacitors. This is needed to ensure the maximum peak-to-peak supply noise requirements are met.

0 Sh.Sasaki over 7 years ago in reply to Biser Gatchev-XID

Guru 13625 points

Hi Biser-san,

Thank you for your support!

When I read DS, I understood that it is necessary for VDDA1P8V_USB0, VDDS_PLL_MPU, VDDS_PLL_CORE_LCD and VDDS_PLL_DDR.

In addition to this, the AM437xSK board connects ferrite beads to VDDS, VDDS_CLKOUT, and VDDS_SRAM_CORE_BG.

Do I not have to connect ferrite beads to these pins?

Best regards,
Sasaki

0 Biser Gatchev-XID over 7 years ago in reply to Sh.Sasaki

TI__Guru**** 393215 points

For these power supplies ferrite beads are not strictly required, but they will improve noise immunity.

0 Sh.Sasaki over 7 years ago in reply to Biser Gatchev-XID

Guru 13625 points

Thank you for your quick support!

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AM4372: Ferrite beads on power supplies