This highly integrated PWM controller, FAN100,
provides several features to enhance the performance
of low-power flyback converters. The proprietary
topology enables simplified circuit design for battery
charger applications. A low-cost, smaller, and lighter
charger results when compared to a conventional
design or a linear transformer. The startup current is
only 10μA, which allows use of large startup resistance
for further power saving.
To minimize the standby power consumption, the
proprietary green-mode function provides off-time
modulation to linearly decrease PWM frequency under
light-load conditions. This green-mode function assists
the power supply meeting the power conservation
requirements.
Using FAN100, a charger can be implemented with
fewest external components and minimized cost. A
typical output CV/CC characteristic envelope is shown in Figure 1.