ACPL-3130-300E Datasheet, PDF (17/20 Pages) AVAGO TECHNOLOGIES LIMITED – Very High CMR 2.5 Amp Output Current IGBT Gate Driver Optocoupler

Thermal Model
(Discussion applies to ACPL-3130, ACPL-J313 and
θ� _LD = 442 °C/W
T _JE
T _JD
θ_LC = 467 °C/W
θ_DC = 126 °C/W
T_C
Inserting the values for q_LC and q_DC shown in Figure 32
gives:
T_JE = P_E •(256°C/W ) + θ_CA + P_D • (57°C/W + θ_CA ) + T_A
T_JD = P_E• (57°C/W ) +θ_CA + P_D • (111°C/W +θ_CA ) + T_A
For example, given P_E = 45 mW, P_O = 250 mW, T_A = 70°C
and q_CA = 83°C/W:
θ_CA = 83 °C/W*
T_A
ACNW3130)
T_JE = LED junction temperature
T_JD = detector IC junction temperature
T_C = case temperature measured at the center of the
package bottom
q_LC = LED-to-case thermal resistance
q_LD = LED-to-detector thermal resistance
q_DC = detector-to-case thermal resistance
q_CA = case-to-ambient thermal resistance
*q_CA will depend on the board design and the placement
of the part.
T_JE = P_E • 339°C/W + P_D•140°C/W + T_A
= 45mW• 339°C/W + 250mW• 140°C/W + 70°C = 120°C
T_JD = P_E •140°C/W + P_D • 194°C/W + T_A
= 45mW• 140°C/W + 250mW •194°C/W + 70°C
T_JE and T_JD should be limited to 125°C based on the
board layout and part placement (q_CA) specific to the
application
Figure 32. Thermal Model.
The steady state thermal model for the ACPL-3130 is
shown in Figure 32. The thermal resistance values given
in this model can be used to calculate the temperatures
at each node for a given operating condition. As shown
by the model, all heat generated flows through q_CA which
raises the case temperature T_C accordingly. The value of
q_CA depends on the conditions of the board design and is,
therefore, determined by the designer. The value of q_CA =
83°C/W was obtained from thermal measurements using a
2.5 x 2.5 inch PC board, with small traces (no ground plane),
a single ACPL-3130 soldered into the center of the board
and still air. The absolute maximum power dissipation
derating specifications assume a q_CA value of 83°C/W.
From the thermal mode in Figure 32 the LED and detector
IC junction temperatures can be expressed as:
( ( ) ) _{( )} • _• ^• T_JE = P_E θ_LC || θ_LD +θ_DC +θ_CA + P_D
θ θ _{LC DC}
θ_LC + θ_DC + θ_LD
+ θ_CA
+ T_A
( ) ^{( ( ) ) • • • TJD = PE}
θ θ _{LC DC}
θ_LC + θ_DC + θ_LD
+ θ_CA
+ P_D
θ_DC || θ_LD + θ_LC + θ_CA + T_A
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