9 Application and Implementation

Note

Information in the following applications sections is not part of the TI component specification,

and TI does not warrant its accuracy or completeness. TI’s customers are responsible for

determining suitability of components for their purposes, as well as validating and testing their design

implementation to confirm system functionality.

9.1 Application Information

9.1.1 Voltage Threshold Accuracy

Voltage monitoring requirements vary depending on the voltage supply tolerance of the device being powered.

Due to the high precision of the TPS3704x (±1% maximum), the device allows for a wider supply voltage

margins and threshold headroom for tight tolerance applications.

For example, take a DC/DC regulator providing power to a core voltage rail of an MCU. The MCU has a

tolerance of ±5% of the nominal output voltage of the DC/DC. The user sets an ideal voltage threshold of ±4%

which allows for ±1% of threshold accuracy. Since the TPS3704x threshold accuracy is ±1%, the user has more

supply voltage margin which can allow for a relaxed power supply design. This gives flexibility to the DC/DC to

use a smaller output capacitor or inductor because of a larger voltage window for voltage ripple and transients.

There is also headroom between the minimum system voltage and voltage tolerance of the MCU to ensure that

the voltage supply will never be in the region of potential failure of malfunction without the TPS3704x asserting a

reset signal.

Figure 9-1 illustrates the supply undervoltage margin and accuracy of the TPS3704x for the example explained

above. Using a low accuracy supervisor will eat into the available budget for the power supply ripple and

transient response. This gives less flexibility to the user and a more stringent DC/DC converter design.

DC/DC nominal output

Regulator output voltage accuracy

Margin for ripple and transients

+ 1% Allowed threshold tolerance

- 1% Minimum system voltage

0%

4%

5%

Potential Failure or Malfunction

Supply

Voltage

Margin

Voltage

Threshold

Accuracy

Figure 9-1. TPS3704x Voltage Threshold Accuracy

TPS3704

SNVSBZ2B – MARCH 2021 – REVISED DECEMBER 2021

www.ti.com

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