TPS6734I

FIXED 12-V 120-mA BOOST-CONVERTER SUPPLY

SLVS127A – AUGUST 1995 – REVISED JANUARY 1999

10

POST OFFICE BOX 655303

APPLICATION INFORMATION

continuous mode

When the converter is delivering heavy loads from low voltage sources, it operates in continuous mode. As

shown in Figure 9, the inductor current does not drop to zero and the ringing is gone from the OUT voltage

waveform.

0

02

4

6

8

10

5

15

CONTINUOUS MODE

20

12

14

16

18

10

1

0.5

0

t – Time –

µs

VI = 5 V

VO = 12 V

IL = 150 mA

Figure 9

pulse-skipping mode

At very light load currents, the TPS6734 cannot generate drive pulses sufficiently narrow to maintain regulation

and operate at 170 kHz. Under these circumstances, the converter operates in a pulse-skipping mode, in which

cycles are skipped. In pulse-skipping mode, the waveforms are irregular and the output ripple contains a

low-frequency component that may exceed 50 mV peak-to-peak.