TS3USB221A-Q1: IC behavior when OE pin is indefinite

Conor

Part Number: TS3USB221A-Q1

Tool/software:

Hi,

We are currently evaluating your product TS3USB221AQRSERQ1, and would appreciate your support regarding the following technical questions.

[Specifications]

Relay pass-through spec: 0 to +1.8V, 30mA or more
RON: 10Ω max
CD + CS (ON): 20pF max
C-contact relay (SPDT)
Ability to set both poles (SXA, SXB) to floating state (e.g., via EN pin)
Operating temperature range: -40℃ to 125℃
Control method: 1:1 or 1:2

[Questions]

When Vcc = 0V, we understand that all relay paths will be in a floating (High-Z) state. Is this understanding correct?
If the OE pin is left floating (undefined state), we believe abnormal operation may occur. Is this understanding correct?
If OE (High) is asserted before Vcc is applied, is there a risk of device damage or abnormal operation?

Best regards,

Conor

6 months ago

0 Clemens Ladisch 6 months ago

Guru 317320 points

As shown in the absolute maximum ratings and the recommended operating conditions, voltages above V_CC are allowed.

Yes.
There is no internal pull-up/-down, so when you leave it floating, it might behave as high, or low, or be oscillating. There also will be shoot-through currents; see [FAQ] How does a slow or floating input affect a CMOS device?
No.

0 Conor 6 months ago in reply to Clemens Ladisch

Guru 12205 points

Hi Clemens,

Thank you for your reply. Let me confirm again that my understanding of 1 and 3 is correct.
① It is permissible for a voltage higher than Vcc to be applied, but when Vcc = 0V, all internal switches will be off (floating).
③ It is permissible for a voltage higher than Vcc to be applied, and there is no problem under this condition.

Thanks,

Conor

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TS3USB221A-Q1: IC behavior when OE pin is indefinite