Datasheet

DRV104
11
SBVS036B
www.ti.com
FIGURE 12. Recommended PCB Layout.
FIGURE 13. PowerPAD Heat Transfer.
FIGURE 14. Heat-Sink Thermal Resistance vs PCB Copper
Area.
PACKAGE MOUNTING
Figure 12 provides recommended printed circuit board (PCB)
layouts for the PowerPAD HTSSOP-14 package. The metal
pad of the PowerPAD HTSSOP-14 package is electrically
isolated from other pins and ideally should be connected to
a ground. For reliable operation, the PowerPAD must be
directly soldered to a circuit board, as shown in Figure 13.
Increasing the heat-sink copper area improves heat dissipa-
tion. Figure 14 shows typical junction-to-ambient thermal
resistance as a function of the PCB copper area.
POWER DISSIPATION
The DRV104 power dissipation depends on power supply,
signal, and load conditions. Power dissipation (P
D
) is equal to
the product of output current times the voltage across the
conducting DMOS transistor times the duty cycle. Using the
lowest possible duty cycle necessary to assure the required
hold force can minimize power dissipation in both the load and
in the DRV104. At 1A, the output DMOS transistor on-resis-
tance is 0.45Ω, increasing to 0.65Ω at current limit.
Solder Attachment
to PCB
2.0
0.33
2.4
0.65
0.0
1.0
2.0
3.5
(all dimensions in mm)
Copper Traces
Signal Trace
Copper Pad
Thermal Vias
DRV104 Die
Pad-to-Board
Solder
THERMAL RESISTANCE vs
PCB COPPER AREA
80
70
60
50
40
30
Thermal Resistance, θ
JA
(°C/W)
012345
Copper Area (inches
2
)
DRV104
PowerPAD
Surface-Mount Package
1oz. Copper