Information based on thermal simulations
Table 5-1 Transient Thermal Impedance (RθJA) and Current CapabilityRθJA [°C/W](1) | Configuration | Current (A)(2) |
without PWM(3) | with PWM(4) |
0.1 sec | 1 sec | 10 sec | DC | 0.1 sec | 1 sec | 10 sec | DC | 10 sec | DC |
1.8 | 4.7 | 8.4 | 23.3 | Dual H-Bridge (both outputs loaded with same current) | 8 | 5.7 | 4.2 | 2.5 | 4 | 2.2 |
Dual H-Bridge (only one output loaded) | 8 | 8 | 6 | 3.5 | 5.4 | 3 |
Single H-Bridge | 16 | 11.3 | 8.4 | 4.9 | 7.9 | 4.4 |
(1) Simulated using 114.3 mm x 76.2 mm x 1.6 mm 4 layer PCB – 2 oz Cu on top and bottom layers, 1 oz Cu on internal planes, 16 cm2 top and bottom layer Cu area, with 13 x 5 thermal via array below thermal pad, 1.1 mm pitch, 0.2 mm diameter, 0.025 mm Cu plating.
(2) Estimated transient current capability at 85 °C ambient temperature for junction temperature rise up to 150°C.
(3) Only conduction losses (I2R) and quiescent current loss at 48 V supply voltage are considered. Maximum ON resistance values at 150°C as per Electrical Characteristics table are considered to calculate conduction losses.
(4) Switching loss estimated by the equation: PSW = VVM x ILoad x fPWM x tRF, where VVM = 48 V, fPWM = 20 KHz, tRF = 110 ns