Information based on thermal simulations
Table 6-1 Transient Thermal Impedance (RθJA) and Current
Capability - full-bridgePART NUMBER | PACKAGE | RθJA [°C/W](1) | Current [A](4) |
---|
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 |
DRV8242-Q1 |
VQFN |
15.1 |
27.9 |
34.56 |
53.7 |
3.0 |
2.3 |
2.0 |
1.6 |
1.8 |
1.5 |
(1) Based on thermal simulations using 40 mm x 40
mm x 1.6 mm
4 layer PCB – 2 oz Cu on top and bottom layers, 1 oz Cu on internal
planes with 0.3 mm thermal via drill diameter, 0.025 mm Cu plating, 1 minimum mm
via pitch.
(4) Estimated transient current capability at 85 °C
ambient temperature for junction temperature rise up to 150°C
(3) Only conduction losses (I2R)
considered
(4) Switching loss roughly estimated by the following equation:
Equation 1. PSW =
VVM x ILoad x fPWM x VVM/SR, where
VVM = 13.5 V, fPWM = 20 KHz, SR = 20 V/µs