8.5 Device I/O Schematics

INx

VCCI

VCCI

VCCI

≅1M

≅1k

Figure 8-3. Input (INx) Default High (Device Without

F Suffix Device) Schematics

VCCI

≅1M

INx

VCCI

≅1k

Figure 8-4. Input (INx) Default Low (Device With F

Suffix Device) Schematics

VCCO

≅33

OUTx

Figure 8-5. Output (OUTx) Schematics

8.5.1 Overvoltage Tolerant Input

The input pins of this device, INx, support input signal voltage in excess of the supply voltage (VCCI) on the input

side of the device as long as the voltage on the inputs remains below the voltages listed in the Recommended

Operating Conditions , and Absolute Maximum Ratings .

This allows the device to support input signal voltages on the inputs when the input supply, VCCI, is unpowered.

In this use case, the outputs transition to the default output state when the input side no longer has a valid

supply.

These inputs also provide the capability of the inputs to down translate input signal voltages up to the VIMAX in

the Recommended Operating Conditions . For example, an input signal 5V high-level can be used while VCCI is

operating a 3.3V.

ISO6420, ISO6421

SLLSG12 – AUGUST 2025

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