Datasheet

1
10 100 1000
SWITCHING FREQUENCY (kHz)
POWER (W)
0.001
0.010
0.100
C
L
= 4400 pF
C
L
= 0 pF
LM5100A, LM5100B, LM5100C, LM5101A, LM5101B, LM5101C
www.ti.com SNOSAW2P –SEPTEMBER 2006–REVISED MARCH 2013
The bootstrap diode power loss is the sum of the forward bias power loss that occurs while charging the
bootstrap capacitor and the reverse bias power loss that occurs during reverse recovery. Since each of these
events happens once per cycle, the diode power loss is proportional to frequency. Larger capacitive loads
require more energy to recharge the bootstrap capacitor resulting in more losses. Higher input voltages (V
IN
) to
the half bridge result in higher reverse recovery losses. The following plot was generated based on calculations
and lab measurements of the diode recovery time and current under several operating conditions. This can be
useful for approximating the diode power dissipation.
The total IC power dissipation can be estimated from the previous plots by summing the gate drive losses with
the bootstrap diode losses for the intended application.
Figure 26. Diode Power Dissipation V
IN
= 50V
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