TPL7407L: Maximum Current Per Channel when Duty=100%@N=7

Ishiwata-san,

The max current per channel at 100% duty for 7ch is slightly over 0.15A @ 70C.

I think using 0.15A as the limit at 70C is acceptable.

Ishiwata-san,

The exact value would depend on the ambient temperature. For this package at 70C, please stick to 150mA.

Ishiwata-san,

Your calculation for power assumes that all 5V will be dropped across the FET.

When the low side switch turns on, it connects the floating output node to GND. This does not necessarily mean that 5V will be dropped across the FET as when the NMOS is on, the resistance is low. 

To get the right power dissipated you have to use the V_OL graph (as this is the voltage across the drain to source when the device is on) which is Figure 1. At 70C at 150mA, the V_OL is less than 0.4V (I will round up to 0.4V).

The total power is then: P= 7* 150mA *0.4V = 0.42W.

This is less than the 0.48W limit for TSSOP and so TPL7407L can sustain 150mA through all 7 channels.