TCA9543A: Can it still work normally when VDPUx<VCC*0.7(VIH)?

Jian Huang

Prodigy 120 points

Part Number: TCA9543A

Can it still work normally when VDPUx<VCC*0.7(VIH)?

over 1 year ago

0 Clemens Ladisch over 1 year ago

Guru 306190 points

Yes. The TCA9543A's control logic can be accessed only from the SDA/SCL pins. The other SDx/SCx pins are analog switches and can use any pull-up voltage (that is not too far below V_CC).

0 Jian Huang over 1 year ago in reply to Clemens Ladisch

Prodigy 120 points

Hi Clemens,

Can it be understood that VDPUm cannot be lower than VCC*0.7 and VDPU0/1 is not limited by VCC?

Thank you!

+1 Clemens Ladisch over 1 year ago in reply to Jian Huang

Guru 306190 points

V_DPUM must be higher than 70% of V_CC to allow the master to control the channels. All V_DPUM and V_DPUx are limited by the maximum pass-through voltage of the pass-gate transistors (see section 9.2.1 and figure 17).

+1 Tyler Townsend over 1 year ago

TI__Mastermind 40523 points

Hi Jian,

The figure that Clemens is referencing is the pass gate voltage spec vs. VCC graph.

Vpass is defined as the smallest pull-up voltage (VDPUM or VDPUx) in the system. Based off this pull-up voltage, the user can determine what is the highest VCC can be used in the system to ensure correct voltage translation.

Also from the recommended operating specs.

1.65V < VCC < 5.5V

1.65V < VDPUx < 5.5V

1.65V < VDPUM < 5.5V

Regards,

Tyler

Interface

Interface forum

TCA9543A: Can it still work normally when VDPUx<VCC*0.7(VIH)?