TDA 16888
The pulse-width-modulation of the PWM section is trailing edge modulated according to
the PWM ramp signal
V
PWM RMP
at pin 15 (PWM RMP) and the input voltage
V
PWM IN
at
pin 14 (PWM IN) (see
In contrast to the PFC section, however, the pulse-
width-modulation of the PWM section is trailing edge triggered with respect to the
internal clock reference CLK OUT in order to avoid undesirable electromagnetic
interference of both sections. Moreover the maximum duty cycle of the PWM is limited
to 50% to prevent transformer saturation.
By means of the above mentioned improved current mode control a stable pulse-width-
modulation from maximum load down to no load is achieved. Finally, in case of no load
conditions the PWM section may as well be disabled by shorting pin 13 (PWM SS) to
ground.
Data Sheet
9
2000-02-28
INFINEON [ INFINEON TECHNOLOGIES AG ]
