TPS23861: PoE PSE with 4x TPS23861 - I2C question

howard banks

Intellectual 580 points

Part Number: TPS23861

I'm looking to develop a 16 port PoE using 4x TPS23861.

I connect the SCL lines and the SDAI lines to the I2C Host.

Do i then daisy chain all the AOUT and AIN through the devices?

AOUT1>AIN2 AOUT2>AIN3 AOUT3>AIN4 AOUT4>AIN5 AOUT5>AIN6 AOUT6>AIN7 AOUT7>AIN8

I leave AIN1 and AOUT8 unconnected?

over 6 years ago

0 Penny Xu over 6 years ago

TI__Genius 15655 points

Hi Howard,

Yes,. You are right. You can leave AIN of the first device and AOUT of the last device open. Please check the typical application schematic in datasheet Figure 50. Thanks.

Best regards,
Penny

0 howard banks over 6 years ago in reply to Penny Xu

Intellectual 580 points

Hi Penny,

As i have 4x TPS23861 in my design, how do i decide what i do with the A3 pin of each device - do i leave open or connect to GND.

0 Manson Chan over 6 years ago in reply to howard banks

TI__Prodigy 70 points

Howard, Penny is having Thanksgiving Holidays. She will give advice on next Monday. Stay tuned.

Regards,
Manson

0 Penny Xu over 6 years ago in reply to howard banks

TI__Genius 15655 points

Hi Howard,

The A3 pin can be either connected to VDD or GND. You just need to make sure when you program the device's address in register 0x11, D3 should be aligned with the A3 pin's status. For example, if the device's A3 is connected to VDD, D3 in register 0x11 should be set to 1; if the device's A3 is connected to GND, D3 in register 0x11 should be set to 0. Thanks.

Best regards,

Penny

Power management

Power management forum

TPS23861: PoE PSE with 4x TPS23861 - I2C question