CPC1977 Datasheet, PDF (3/7 Pages) Clare, Inc. – i4-PAC™ Power Relay

INTEGRATED CIRCUITS DIVISION
CPC1977
2 Thermal Characteristics
Parameter
Thermal Resistance (Junction to Case)
Thermal Resistance (Junction to Ambient)
Junction Temperature (Operating)
Conditions
-
Free Air
-
Symbol
_JC
_JA
T_J
Rating
0.35
33
-40 to +100
Units
°C/W
°C/W
°C
2.1 Thermal Management
Device high current characterization was performed using Kunze heat sink KU 1-159, phase change thermal interface
material KU-ALC 5, and transistor clip KU 4-499/1. This combination provided an approximate junction-to-ambient
thermal resistance of 12.5°C/W.
2.2 Heat Sink Calculation
Higher load currents are possible by using lower thermal resistance heat sink combinations.
Heat Sink Rating
θ_CA =
(T_J
-
T_A)
I²
L(99)
I²
L
•
P
D(99)
- θ_JC
T_J = Junction Temperature (°C), T_J ≤ 100°C *
T_A = Ambient Temperature (°C)
I = Load Current with Case Temperature @ 99°C (A )
L(99)
DC
I_L = Desired Operating Load Current (A_DC), I_L ≤ I_L(MAX)
θ_JC = Thermal Resistance, Junction to Case (°C/W) = 0.35°C/W
θ_CA = Thermal Resistance of Heat Sink & Thermal Interface Material , Case to Ambient (°C/W)
P_D(99) = Maximum power dissipation with case temperature held at 99ºC = 2.86W
* Elevated junction temperature reduces semiconductor lifetime.
NOTE: The exposed surface of the DCB substrate is not to be soldered.
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