Preliminary Datasheet

LP6212

LP6212 –00 Version1.0

Datasheet

May.-2014

Page 5 of 6

Operation Information

The LP6212 uses a 1.2MHz fixed frequency,

current-mode regulation architecture to regulate the

output voltage. The LP6212 measures the output

voltage through an external resistive voltage divider

and compares that to the internal 0.6V reference to

generate the error voltage to the inductor current to

regulate the output voltage. The use of current-mode

regulation improves transient response and control

loop stability.

When the LP6212 is disabled (EN=Low), both power

switches are off. There is no current path from SW to

OUT. Therefore, the output voltage discharges to

ground. When the LP6212 is enabled (EN=High),a

limited start-current charges the output voltage rising to

SW, then TH part operates in force PWM mode for

regulating the output voltage to the target value. At the

beginning of each cycle, the N-channel MOSFET

switch is turned on, forcing the inductor current to rise,

The current at the source of the switch is internally

measured and converted to a voltage by the current

sense amplifier. That voltage is compared to the error

voltage. When the inductor current rises sufficiently, the

PWM comparator turns off the switch, forcing the

inductor current to the output capacitor through the

internal P-Channel MOSFET rectifier, which forces the

inductor current to decrease. The peak inductor current

is controlled by the error voltage. Thus the output

voltage controls the inductor current to satisfy the lode.

Setting the Output Voltage

Set the output voltage by selecting the resistive voltage

divider ratio. The voltage divider drops the output

voltage to the 0.6V feedback voltage. Use a 100K

resistor for R2 of the voltage divider. Determine the

hi g h -si d e re sis t or R 1 by t he e qua t i on:

Vout=(R1/R2+1) x VFB

Vout=(R1/R2+1) x 0.6V