LM****4/-Q1 The LM****4 incorporates a voltage mode constant
frequince PWM architecture, in adition,, input voltage feedforward
is used to stabilize the loop gain against variations in input
voltage. This allows the loop compensation to be optimized for
transient performance. The power MOSFET, in conjunction with the
diode, produce a rectangular waveform at the switch pin, that
swings from about zero volts to VIN. The inductor and output
capacitor average this waveform to become the regulator output
voltage. By adjusting the duty cycle of this waveform, the output
voltage can be controlled. The error amplifier compares the output
voltage with the internal reference and adjusts the duty cycle to
regulate the output at the desired value. The internal loop
compensation of the -ADJ option is optimized for outputs of 5V and
below. If an output voltage of 5 V or greater is required, the *5.0
option can be used with an external voltage divider. The minimum
output voltage is equal to the reference voltage, that is, 1.**5 V
(typ).
