PCA9545A support 1.8V

Nanfang Liao

Intellectual 2085 points

Other Parts Discussed in Thread: PCA9545A

Hello,

Our PCA9545A Vcc supply range is 2.3V to 5.5V, so Vcc can't support 1.8V supply. The VIH and Vil of our part spec is as below(0.3Vcc~0.7Vcc), so it can't support 1.8V LVCOMS, but our PCA9545A can support 1.8V in the datasheet, can you help to explain it? thanks

over 7 years ago

0 Siby James over 7 years ago

TI__Expert 5140 points

Hi Nanfang,

The VIH and VIL spec shown in the datasheet is in accordance with the I2C specification (written by NXP formerly Phillips Semi). This is in order to ensure that you meet the threshold for high value input voltage level and low value input voltage level.

Thanks,
Siby

0 Nanfang Liao over 7 years ago in reply to Siby James

TI__Intellectual 2085 points

Hello Siby,

Thanks for your quick response. So our part shouldn't support 1.8V input, correct?

Regards,

Nanfang

0 Siby James over 7 years ago in reply to Nanfang Liao

TI__Expert 5140 points

Correct,

The device cannot be powered by the 1.8V, but the VIL voltage will be 30% of this supply voltage, and the VIH 70% of the supply voltage.

Thanks,
Siby

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PCA9545A support 1.8V