Ambient Temperature - (qC)

0

50

100

150

200

0

100

200

300

400

500

600

700

D001

D001

VCC1 = VCC2 = 2.7 V

VCC1 = VCC2 = 3.6 V

VCC1 = VCC2 = 5.5 V

22

ISO7631FM, ISO7631FC, ISO7641FC

SLLSEC3F – SEPTEMBER 2012 – REVISED APRIL 2016

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9.3.1.1 Safety Limiting Values

Safety limiting intends to prevent potential damage to the isolation barrier upon failure of input or output circuitry.

A failure of the IO can allow low resistance to ground or the supply and, without current limiting, dissipate

sufficient power to overheat the die and damage the isolation barrier potentially leading to secondary system

failures.

PARAMETER

TEST CONDITIONS

MIN

TYP

MAX

UNIT

IS

Safety input, output, or supply

current

DW-16

θJA = 77.5 °C/W, VI = 5.5V, TJ = 150°C, TA = 25°C

293

mA

θJA = 77.5 °C/W, VI = 3.6V, TJ = 150°C, TA = 25°C

448

θJA = 77.5 °C/W, VI = 2.7V, TJ = 150°C, TA = 25°C

597

TS

Maximum safety temperature

150

°C

The safety-limiting constraint is the absolute maximum junction temperature specified in the absolute maximum

ratings table. The power dissipation and junction-to-air thermal impedance of the device installed in the

application hardware determines the junction temperature. The assumed junction-to-air thermal resistance in the

Thermal Information table is that of a device installed on a High-K Test Board for Leaded Surface Mount

Packages. The power is the recommended maximum input voltage times the current. The junction temperature is

then the ambient temperature plus the power times the junction-to-air thermal resistance.

Figure 22. Thermal Derating Curve for Safety Limiting Current per VDE