PM6686 STMicroelectronics, PM6686 Datasheet - Page 28

• Manufacturer Part Number: PM6686
• Description: Dual Step-down Controller With Adjustable Voltages, Adjustable Ldo And Auxiliary Charge Pump Controller For Notebook
• Manufacturer: STMicroelectronics

Device description
8.1.3
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PWM
PWM implements the continuous current mode (CCM). During T
is turned on and the inductor current starts increasing. When the Ton is elapsed the high-
side MOSFET is turned off and after a dead time during which neither MOSFET conducts,
the low-side MOSFET turns on. The inductor current decreases until these three conditions
are verified:
●
●
●
When these conditions are satisfied a new T
PWM operation mode has a quasi-constant switching frequency, avoiding any audible noise
issue and the continuous current mode assures better load transitions despite of a lower
efficiency at light loads.
Figure 47.
Output voltage reaches the regulation voltage
Inductor current is below the current limit
T
OFFMIN
Inductor
current
Output
voltage
Vreg
Inductor current and output voltage in PWM mode
is elapsed
Ton
Doc ID 15281 Rev 4
Toff
ON
starts.
ON
, the high-side MOSFET
t
PM6686