HCPL-3150 Datasheet, PDF (17/22 Pages) Agilent(Hewlett-Packard) – 0.5 Amp Output Current IGBT Gate Drive Optocoupler

The value of 4.25 mA for I_CC in the previous equation was
obtained by derating the I_CC max of 5 mA (which occurs
at -40°C) to I_CC max at 90°C (see Figure 7).
Since P_O for this case is greater than P_O(MAX), Rg must be
increased to reduce the HCPL-3150 power dissipation.
P = P - P _{O(SWITCHING MAX)}
O(MAX) O(BIAS)

= 154 mW - 85 mW

= 69 mW
From the thermal mode in Figure 28a the LED and detec-
tor IC junction temperatures can be expressed as:
T_JE = P_E ^• (θ_LC||(θ_LD + θ_DC) + θ_CA)
   ( )  + P D•      θ
LC
θ •θ
LC DC
+
θ
DC
+
θ
LD
+ θ_CA
+ T_A
   ^{( )  TJD = PE   }   θ_LC^θ+^LCθ^• _D^θ_CD+^C θ_LD
+
θ
CA
+ P_D^•(θ_DC||(θ_LD + θ_LC) + θ_CA) + T_{A
ES W(MA X )    = PO  (SWITCHfINGMAX)}
= 69 mW _{= 3.45 µJ}
  20 kHz
For Qg = 500 nC, from Figure 27, a value of E_SW = 3.45 µJ
gives a Rg = 41 Ω.
Thermal Model (HCPL-3150)
The steady state thermal model for the HCPL-3150 is
shown in Figure 28a. 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 θ_CA which
raises the case temperature T_C accordingly. The value of
θ_CA depends on the conditions of the board design and
is, therefore, determined by the designer. The value of
θ
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 HCPL-3150 soldered into the
center of the board and still air. The absolute maximum
power dissipation derating specifica­tions assume a
θ_CAvalue of 83°C/W.
Inserting the values for θ_LC and θ_DC shown in Figure 28
gives:
T_JE = P_E^•(230°C/W + θ_CA) + P_D^•(49°C/W + θ_CA) + T_A
T_JD = P_E^•(49°C/W + θ_CA) + P_D^•(104°C/W + θ_CA) + T_A
For example, given P_E = 45 mW, P_O = 250 mW, T_A = 70°C
and θ_CA= 83°C/W:
T_JE = P_E^•313°C/W + P_D^•132°C/W + T_A
 = 45 mW^•313°C/W + 250 mW ^•132°C/W + 70°C = 117°C
T_JD = P_E^•132°C/W + P_D^•187°C/W + T_A
 = 45 mW^•132C/W + 250 mW ^•187°C/W + 70°C = 123°C
T_JE and T_JD should be limited to 125°C based on the board
layoutand part placement (θ_CA) specificto the applica-
tion.
θ_LD = 439°C/W
T_JE
T_JD
θ_LC = 391°C/W
θ_DC = 119°C/W
T_C
θ_CA = 83°C/W*
T_A
Figure 28a. Thermal Model.
T_JE = LED junction temperature
θ^{TTTTTJLDCCJJCED======CCLDAEdcLEESNaEeDTETsDtEJEeeTCU}-RE^ctTtNo^MteOOC^o-PmFRTcr^EITIa^OpRICHCsNAeEJe^{TrjUTPuUatENA}h^RtnMCuCEec^PTKrrtIEMeOAmi^RoENGmAAnaETTSle^EUtBUrea^MROe^RsmPETs^EuETi^Dspr^ROte^AeAMad^TrTna^{UTactHRteuEEtrhee center of the package bottom}
θθ_D^{θθθLDCLLDCDC=====}
L_LE_ED_D-T_-O_t-_oC_-A_dS_eE_tT_eH_cE_tR_oM_rA_tL_heR_rE_mSIS_aT_lA_rN_eC_siE_stance
LED-TO-DETECTOR THERMAL RESISTANCE
D^dE^eT^tE^eC^cT^tO^oR^r-^-T^tO^o-^-C^cA^aS^sE^eT^tH^hE^eR^rM^mAL^alR^rE^eS^sIS^isT^tA^aNⁿC^cE^e
∗θθ_C^*Cθθ_AA^CCw^AA=iW=Tll^CHIcLd^AELaeSPsDEpe_LE-Ae^T-Pt_COn^Eo_E-Nd^A-_MD^aMo_E^mOBn_NNIT^bEt^NTOiheHTFen^ETTbt^HBHEtoOEhRAa_P^eMRr_Adr^ADRmLd_TDR.^aEe^ElSs^SrIi^{GegISNsnTiAAsatNN}na^DCndEctehe placement of the part.
HCPL-3150 fig 28
17