TPS61097A

VIN

L

VOUT

GND

EN

TPS22920L

VIN

VOUT

EN

L1

C2

C1

V

+3.3V

OUT

GND

R1

R2

V

0.9V to 3.3V

IN

TPS61097A-33

V

0.9 V to 3.3V

IN

VOUT

EN

L

GND

VIN

L1

R2

R1

C1

C2

V

+3.3V

OUT

TPS61097A-33

SLVSCF2A – JANUARY 2014 – REVISED DECEMBER 2014

www.ti.com

9 Application and Implementation

NOTE

Information in the following applications sections is not part of the TI component

specification, and TI does not warrant its accuracy or completeness. TI’s customers are

responsible for determining suitability of components for their purposes. Customers should

validate and test their design implementation to confirm system functionality.

9.1 Application Information

9.1.1 Adjustable Bypass Switching

The EN pin can be set up as a low voltage control for the bypass switch. By setting the desired ratio of R1 and

R2, the TPS61097A-33 can be set to switch on the bypass at a defined voltage level on VIN. For example,

setting R1 and R2 to 200 K

Figure 17. Adjustable Bypass Switching

9.1.2 Managing Inrush Current

Upon startup, the output capacitor of the boost converter can act as a virtual short circuit. The amount of inrush

current is dependent on the rate of increase of the input voltage, the inductance used with the converter, the

output capacitance and the parasitic circuit resistance. One method to reduce the inrush current is to use a load

switch with controlled turn-on. Texas Instruments has a large offering of controlled slew rate load switches which

can be found at www.ti.com/loadswitches. Below is an example circuit that has a load switch with controlled turn-

on.

Figure 18. Example Circuit with Load Switch

12

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