8.2.3 Application Curves (continued)

Figure 8-13. 4 Meter Post-Channel Without TUSB211A

Figure 8-14. 4 Meter Post-Channel With TUSB211A EQ=2

8.3 Power Supply Recommendations

On power up, the interaction of the RSTN pin and power on ramp could result in digital circuits not being set

correctly. The device should not be enabled until the power on ramp has settled to the minimum recommended

supply voltage or higher for a correct power on reset of the digital circuitry. If RSTN cannot be held low by

microcontroller or other circuitry until the power on ramp has settled, then an external capacitor from the RSTN

pin to GND is required to hold the device in the low power reset state.

The RC time constant should be larger than five times of the power on ramp time (0 to VCC). With a typical

internal pullup resistance of 500 kΩ, the recommended minimum external capacitance is calculated as:

Ramp Time × 5 ÷ 500 kΩ 

(1)

8.4 Layout

8.4.1 Layout Guidelines

Although the land pattern has matched trace width to pad width, optimal impedance control is based on the

user's own PCB stack-up. The recommendation is to maintain 90 Ω differential routing underneath the device.

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TUSB211A

SLLSFW2 – SEPTEMBER 2023

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Product Folder Links: TUSB211A