ISO721, ISO721M

ISO722, ISO722M

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SLLS629I – JANUARY 2006 – REVISED FEBRUARY 2010

IEC 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

100

Safety input, output, or supply current

mA

153

Maximum case 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 junction-to-air thermal resistance in the Thermal

Characteristics table is that of a device installed in the JESD51-3, Low Effective Thermal Conductivity Test Board

for Leaded Surface Mount Packages and is conservative. 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.

Table 2. THERMAL CHARACTERISTICS for D-8 PACKAGE

(over recommended operating conditions unless otherwise noted)

PARAMETER

TEST CONDITIONS

MIN

TYP

MAX

UNIT

263

°C/W

Junction-to-air

125

°C/W

Junction-to-board thermal resistance

44

°C/W

Junction-to-case thermal resistance

75

°C/W

ISO72x

159

Input a 100 Mbps 50% duty cycle square wave

Device power dissipation

mW

ISO72xM

195

Input a 150 Mbps 50% duty cycle square wave

(1)

Tested in accordance with the low-K or high-K thermal metric definition of EIA/JESD51-3 for leaded surface mount packages.

Table 3. THERMAL CHARACTERISTICS for DUB-8 PACKAGE

(over recommended operating conditions unless otherwise noted)

PARAMETER

TEST CONDITIONS

MIN

TYP

MAX

UNIT

188

°C/W

Junction-to-air

117

°C/W

Junction-to-board thermal resistance

82.1

°C/W

Junction-to-case thermal resistance

60

°C/W

Device power dissipation

ISO721

159

mW

Input a 100 Mbps 50% duty cycle square wave

(1)

Tested in accordance with the low-K or high-K thermal metric definition of EIA/JESD51-3 for leaded surface mount packages.

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