The AME5138 is a fixed off-time step-up DC/DC converter
in a small 5-lead SOT-25 package. The AME5138
is ideal for LCD panels requiring low current and high efficiency
as well as LED applications for cellular phone backlighting,
PDAs,and other hand-held devices. The low 400ns
off-time allows the use of tiny external components.
AME5138 is designed to drive up to four white LEDs
in series with a constant current from a single Li-lon battery.
To control LED brightness, the LED current can be
adjusted by applying a PWM (pulse width modulated)
signal with a frequency range of 100Hz to 50KHz to the
EN pin.