TPS16633x

31

PŸ

IN

OUT

dVdT

ILIM

P_IN

FLT

GND

SHDN

UVLO

OVP

MODE

IMON

PGOOD

Input

*

Output

*

(

)

( )

(

)

( )

( )

IN

spike Absolute

IN

Load

IN

L

V

V

I

C

=

+

´

21

TPS1663

www.ti.com

SLVSET9A – SEPTEMBER 2018 – REVISED OCTOBER 2018

Product Folder Links: TPS1663

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Copyright © 2018, Texas Instruments Incorporated

10.1 Transient Protection

In case of short circuit and over load current limit, when the device interrupts current flow, input inductance

generates a positive voltage spike on the input and output inductance generates a negative voltage spike on the

output. The peak amplitude of voltage spikes (transients) depends on the value of inductance in series to the

input or output of the device. These transients can exceed the Absolute Maximum Ratings of the device if steps

are not taken to address the issue.

Typical methods for addressing transients include:

•

Minimizing lead length and inductance into and out of the device

•

Using large PCB GND plane

•

Use of a Schottky diode across the output and GND to absorb negative spikes

•

transients.

The approximate value of input capacitance can be estimated with Equation 10.

where

•

•

•

•

(10)

Some applications may require additional Transient Voltage Suppressor (TVS) to prevent transients from

exceeding the Absolute Maximum Ratings of the device. These transients can occur during positive and negative

surge tests on the supply lines. In such applications it is recommended to place at least 1 µF of input capacitor.

The circuit implementation with optional protection components (a ceramic capacitor, TVS and schottky diode) is

shown in Figure 18

Figure 18. Circuit Implementation with Optional Protection Components for TPS1663x

10.2 Application Limitations

This section highlights some limitations in the application which were identified during bench evaluation of the

existing TPS1663 silicon on the evaluation module (EVM)