P = R

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DRV8803

www.ti.com

SLVSAW5A

– JULY 2011 – REVISED JULY 2011

THERMAL INFORMATION

Thermal Protection

The DRV8803 has thermal shutdown (TSD) as described above. If the die temperature exceeds approximately

150

°C, the device will be disabled until the temperature drops to a safe level.

Any tendency of the device to enter TSD is an indication of either excessive power dissipation, insufficient

heatsinking, or too high an ambient temperature.

Power Dissipation

Power dissipation in the DRV8803 is dominated by the power dissipated in the output FET resistance, or

RDS(ON). Average power dissipation of each FET when running a static load can be roughly estimated by

Equation 1:

(1)

average current drawn by the load. Note that at start-up and fault conditions this current is much higher than

normal running current; these peak currents and their duration also need to be taken into consideration. When

driving more than one load simultaneously, the power in all active output stages must be summed.

The maximum amount of power that can be dissipated in the device is dependent on ambient temperature and

heatsinking.

be taken into consideration when sizing the heatsink.

Heatsinking

The DRV8803 package uses a standard SOIC outline, but has the center pins internally fused to the die pad in

order to more efficiently remove heat from the device. The two center leads on each side of the package should

be connected together to as large a copper area on the PCB as is possible to remove heat from the device. If the

copper area is on the opposite side of the PCB from the device, thermal vias are used to transfer the heat

between top and bottom layers.

In general, the more copper area that can be provided, the more power can be dissipated.

Copyright

© 2011, Texas Instruments Incorporated

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Product Folder Link(s): DRV8803