BD83740HFP-M Datasheet, PDF (20/32 Pages) Rohm – 1ch Source Driver for Automotive

BD83740HFP-M
Thermal Loss
Vf_diode
D1
PWM_in
ZD1
D2
D3
DC_in
+B
RPBUS
VIN_F_REF
CVIN
RVIN_F
VIN_F
VIN
IOUT
CCRT RCRT
CRT BD83740HFP-M
DISC
PBUS
FIN
GND
IOUT
CIOUT
Figure 26. Application Circuit Diagram for Thermal Description
Thermal design should meet the following equation:
Pd > Pc = (+B – Vf_diode - VIN_F_REF – Vf_led×N)×IOUT + IVIN×VIN
Pd = (1/θja) × (Tjmax - Ta) or (1/θjc) ×(Tjmax - Tc)
where:
Pd is the Power Dissipation
Pc is the Power Consumption
+B is the Battery Voltage
Vf_diode is the Reverse Connection Preventing Diode Vf
VIN_F_REF is the VIN_F Terminal Voltage (VIN-VIN_F)
Vf_led is the LED Vf
N is the Number of LED Levels
IOUT is the Output Current
IVIN is the Circuit Current
VIN is the Power Supply Voltage
θja is the Thermal Resistance between Tj and Ta
θjc is the Thermal Resistance between Tj and Tc
Tjmax is the Max Joint Temperature (150°C)
Ta is the Ambient Temperature
Tc is the Case Surface Temperature
Vf_led × N
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TSZ22111・15・001
20/28
TSZ02201-0T1T0C700170-1-2
06.Sep.2016 Rev.002