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L6911C

Efficiency

Figure 11 shows the measured efficiency versus load current for different values of output voltage. The measure

was done at Vin=5V for different values of the output voltage (2.05V and 2.75V). Two different measurements

were done using IC supply voltage of 5V and 12V.

In the application two mosfets STS12NF30L (30V, 10m

Ω typ @ Vgs=4.5V) connected in parallel are used for

both the low and the high side.

The board has been layed out with the possibility to use up to three SO8 mosfets for both high and low side

switch. Two D

flexibility in meeting different requirements.

Figure 11. Efficiency vs. load

Vcc = 12V; Vin = 5V

Vcc = Vin = 5V

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95

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Out put Current [A]

Vout = 1.7V

Vout = 2.0V

Vout = 2.5V

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Out put C urren t [A ]

Vout = 1.7V

Vout = 2.0V

Vout = 2.5V

Load Transient Response

Figure 12 shows the demo board response to a load

transient application. The load transient applied

changes from 0A to 14A on the output current (Chan-

nel 4). It may be observed that output voltage (Chan-

nel 1) remains within the 100mV tolerance across the

regulated voltage. Figure 13 shows details about the

the circuit response during current rising and falling

edge; it is possible to observe that the duty cycle of

the Phase signal (Channel 2) goes up to 100% or

down to 0% if necessary.

Figure 12. Load Transient Response

Figure 13. Load Transient Response Details