V = 3.6V, V

= V

2.6V

CTRL = V

R

= 100

I

= 0mA

C

= 10 F

IN

OUT

LOAD =

IN

OUT

LOAD

LOAD

W

m

V = 3.6V,

V

= 1.8V / 2.5V ramp up / down

I

= 5mA

VSEL 2+3 toggled, VSEL1 = GND

CTRL = GND

IN

OUT

OUT

V

= 3.6V

V

= 2.6V

R

= 100

CTRL = GND

IN

OUT

OUT

W

V

= 3.6V

V

= 2.6V

R

= 100

CTRL = GND

IN

OUT

OUT

W

TPS82740A, TPS82740B

www.ti.com

SLVSCE3A – JUNE 2014 – REVISED JUNE 2014

Typical Application (continued)

TPS82740 uses a tiny ceramic input capacitor. When a ceramic capacitor is combined with trace or cable

inductance, such as that from a wall adapter, a load step at the output can induce ringing at the VIN pin. This

ringing can couple to the output and be mistaken as loop instability or can even damage the module. In this

circumstance, additional ceramic 'bulk" capacitance, such as electrolytic or tantalum, should be placed between

the input of the module and the power source lead to reduce ringing that occurs between the inductance of the

power source leads and the module.

11.2.2.2 Output Capacitor Selection

For most applications, the integrated output capacitor at the VOUT pin is sufficient.

In order to further reduce the output voltage ripple and improve the load transient performance an additional

external output capacitance may be used. For most applications an additional 4.7µF or 10µF capacitor will be

sufficient. Care should be taken that the total effective capacitance present at the output does not exceed 10µF

in order to guarantee loop stability. Ceramic capacitors with low ESR values have the lowest output voltage ripple

and are recommended.

At the LOAD output pin, no additional output capacitor is required. For applications demanding external

capacitance connected to the LOAD pin, the total capacitance should not exceed 10µF.

11.2.3 Application Curves

Figure 41. TPS82740B Device Enable and Start up

Figure 44. TPS82740A Dynamic Output Voltage Scaling:

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