TPS60120, TPS60121, TPS60122, TPS60123, TPS60124, TPS60125

REGULATED 200-mA HIGH EFFICIENCY CHARGE PUMP

DC/DC CONVERTERS

SLVS257B – NOVEMBER 1999 – REVISED AUGUST 2000

16

POST OFFICE BOX 655303

TYPICAL CHARACTERISTICS

–0.5

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

–0.2 –0.1 0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

t – Time (Start-Up Timing – ms

VO – V

VI = 2.4 V

RLOAD = 16.5 Ω

ENABLE – V

TPS60120

OUTPUT VOLTAGE

vs

TIME

(START-UP TIMING)

Figure 26

APPLICATION INFORMATION

capacitor selection

The TPS6012x charge pumps require only four external capacitors as shown in the basic application circuit.

Their values and types are closely linked to the output current and output noise/ripple requirements. For lowest

noise and ripple, low ESR (< 0.1

Ω) capacitors should be used for input and output capacitors.

The input capacitor improves system efficiency by reducing the input impedance. It also stabilizes the input

current of the power source. The input capacitor should be chosen according to the power supply used and the

distance from the power source to the converter IC. The input capacitor also has an impact on the output ripple

either ceramic or low-ESR tantalum; aluminum capacitors are not recommended.