u

t

u

(IN)

(INRUSH)

(OUT)

dVdT

dV

V

I

C

I

C

dT

t

VIN

VOUT

FLTb

VIN

VOUT

FLTb

IIN

11

TPS1663

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SLVSET9A – SEPTEMBER 2018 – REVISED OCTOBER 2018

Product Folder Links: TPS1663

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Copyright © 2018, Texas Instruments Incorporated

Feature Description (continued)

8.3.2 Overvoltage Protection (OVP)

The TPS1663x incorporate circuitry to protect the system during overvoltage conditions. The TPS16630 features

the downstream load. To program the OVP threshold externally, connect a resistor divider from IN supply to OVP

terminal to GND as shown in the Typical Application circuit. The TPS16632 features an internally fixed 40 V

input voltage exceeds 40 V. During the output voltage clamp operation, the power dissipation in the internal

enter into thermal shutdown.

Figure 1 illustrates the overvoltage cut-off functionality and Figure 2 illustrates the over voltage clamp

functionality .

TPS16630

OVP Setting at 33 V

Figure 1. Over Voltage Cut-off Response at 33-V Level

TPS16632

Figure 2. Over Voltage Clamp Response

8.3.3 Hot Plug-In and In-Rush Current Control

The devices are designed to control the inrush current upon insertion of a card into a live backplane or other

"hot" power source. This limits the voltage sag on the backplane’s supply voltage and prevents unintended resets

of the system power. The controlled start-up also helps to eliminate conductive and radiative interferences. An

external capacitor connected from the dVdT pin to GND defines the slew rate of the output voltage at power-on.

The fastest output slew rate of 24/240 µscan be achieved by leaving dVdT pin floating. The inrush current can be

calculated using Equation 1.

(1)

where

(2)

Figure 3 illustrates in-rush current control performance of the device during Hot Plug-In.