HCPL-3120-560E Datasheet, PDF (21/24 Pages) AVAGO TECHNOLOGIES LIMITED – 2.5 Amp Output Current IGBT Gate Drive Optocoupler

θ_LD = 442 °C/W
T_JE
T_JD
θ_LC = 467 °C/W
θ_DC = 126 °C/W
T_C
θ_CA = 83 °C/W*
T_A
T_JE = LED junction temperature 
T_JD T=_JEd=eLtEeDcJtUoNrCICTIOjuNnTcEtMioPEnRtAeTmURpEerature 
T_C
q_LC
T_=JDc=_aD_sE_eT_tE_eC_mTO_pR_eIC_raJ_tU_uN_rC_eT_mIO_eN_aT_sE_uM_rP_eE_dRA_aT_tU_tR_hE_e
T_=C
= CASE TEMPERATURE MEASURED AT THE
LE_CD_EN-_Tto_ER-c_Oa_Fse_THt_Eh_Pe_Arm_CKa_Al_Gr_Ee_Bsi_Os_Tta_TOn_Mce 
center
of
the
package
bottom 
q_LD
q_DC
θ_=LCL=_EL_DED_-t-T_oO_-d-C_eA_tS_eE_cT_tH_oE_rR_tM_hA_eL_rmRE_aS_lIS_reTA_siN_sC_taE_nce 
θθ_=LDDCd==_eLD_tEE_eDT_c-ET_tCOoT-rDO_-tER_oT-TE_-OcC_a-TCsOA_eRS_tEThHT_eEH_rRE_mMRAM_aL_lArLReER_sSE_iI_sSStITSaAT_nNA_cCN_eEC_{  E}
q_CA ^θ=CAc⁼a^Cs^Ae^S-t^Eo^-T-^Oa^-m^AMb^Bie^IEn^Nt^Tt^Th^He^Er^Rm^MAa^Ll r^Re^Es^Si^Is^St^Ta^An^Nc^Ce^E 
*q_C^*_A^θCw^A i^WTll_HILd_ELe_PDp_LEe_APn_CEEd^NMDo_EOn_NNTt^Th_OHFe^ETb^BHo^OEa^APr^RAd^DRd_TD.Ee^Ss^Ii^Gg^Nn^Aa^Nn^Dd the placement of the part.
Figure 28. Thermal model.
LED Drive Circuit Considerations for Ultra High CMR Per-
formance. (Discussion applies to H_HCC_PP_LL_--₃3₁₂1₀2_f0_ig,₂H₈CPL-J312,
and HCNW3120)
Without a detector shield, the dominant cause of op-
tocoupler CMR failure is capacitive coupling from the
input side of the optocoupler, through the package, to
the detector IC as shown in Figure 29. The HCPL-3120
improves CMR perform-ance by using a detector IC with
an optically transparent Faraday shield, which diverts the
capaci­tively coupled current away from the sensitive IC
circuitry. How­ever, this shield does not eliminate the ca-
pacitive coupling between the LED and optocoup­ler pins
5-8 as shown in Figure 30. This capacitive coupling causes
perturbations in the LED current during common mode
transients and becomes the major source of CMR failures
for a shielded optocoupler. The main design objective of
a high CMR LED drive circuit becomes keeping the LED
in the proper state (on or off ) during common mode
transients. For example, the recommended application
circuit (Figure 25), can achieve 25 kV/µs CMR while mini-
mizing component complexity.
Techniques to keep the LED in the proper state are
discussed in the next two sections.
1
8
C_LEDP
2
7
3
6
C_LEDN
4
5
1
C_LEDO1
8
C_LEDP
2
7
C_LEDO2
3
C_LEDN
6
4
5
SHIELD
Figure 29. Optocoupler input to output capacitance model for unshielded
optocouplers.
Figure 30. Optocoupler input to output capacitance model for shielded
optocouplers.
HCPL-3120 fig 29
HCPL-3120 fig 30
21