6.3.4.2 Output Behavior in Case of a Missing High-Side Supply

As shown in Figure 6-5, the device provides a constant bitstream of logic 0's at the output if the high-side supply

is missing. DOUT is permanently low when the high-side supply is missing. A one is not generated every 128

clock pulses, which differentiates this condition from a valid negative full-scale input. This feature helps identify

high-side power-supply problems on the board.

CLKIN

DOUT

AVDD

Data valid

Data valid

0

Figure 6-5. Output of the AMC0136 in Case of a Missing High-Side Supply

6.4 Device Functional Modes

The AMC0136 operates in one of the following states:

• OFF-state: The low-side of the device (AVDD) is not supplied. The device is not responsive and DOUT is in

high-impedance state. Internally, DOUT is clamped to DVDD and DGND by ESD protection diodes.

• Missing high-side supply: DVDD is supplied within the Recommended Operating Conditions. VAVDD is below

the AVDDUV threshold. The device outputs a constant bitstream of logic 0's, as described in the Output

Behavior in Case of a Missing High-Side Supply section.

• Input voltage range violation (full-scale input): VAVDD and VDVDD are supplied within the respective

recommended operating conditions but the input voltage VIN exceeds the clipping voltage (|VIN| > |VClipping|).

The device outputs a fixed pattern, as described in the Output Behavior in Case of a Missing High-Side

Supply section.

• Normal operation: VAVDD, VDVDD, and VIN are within the recommended operating conditions. The device

outputs a digital bitstream as explained in the Digital Output section.

Table 6-1. Device Operational Modes

OPERATING

CONDITION

VDVDD

VAVDD

VCM

(VINP + VINN) / 2

VIN

(VINP – VINN)

DEVICE

RESPONSE

OFF

VDVDD < DVDDUV

Don't care

Don't care

Don't care

DOUT is in a Hi-Z state.

DOUT is clamped to DVDD

and DGND by ESD protection

diodes.

Missing high-side

supply

Valid(1)

VAVDD < AVDDUV

Don't care

Don't care

DOUT is constantly low.

Input voltage range

violation

Valid(1)

Valid(1)

Valid(1)

|VIN| > VClipping

The device outputs a single 1

or a single 0 every 128th clock

cycle

Normal operation

Valid(1)

Valid(1)

Valid(1)

Valid(1)

Normal operation.

(1)

Valid means within recommended operating conditions.

AMC0136

SBASAZ0 – AUGUST 2024

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