US 12,451,805 B2
Feedback current depended ramp generator for switched mode power supply
Matthias Hoffmann, Dresden (DE)
Assigned to GlobalFoundries U.S. Inc., Malta, NY (US)
Filed by GlobalFoundries U.S. Inc., Malta, NY (US)
Filed on Jul. 12, 2023, as Appl. No. 18/351,059.
Prior Publication US 2025/0023468 A1, Jan. 16, 2025
Int. Cl. H02M 3/158 (2006.01); H02M 1/00 (2006.01)
CPC H02M 3/158 (2013.01) [H02M 1/0009 (2021.05)] 15 Claims
OG exemplary drawing
 
1. A Switched-Mode Power Supply (SMPS), comprising:
an energy storage device;
a current sense circuit configured to produce a feedback current according to a current flowing through the energy storage device; and
a ramp generator circuit configured to produce a ramp signal according to the feedback current,
wherein the SMPS is configured to control a duty cycle of the current flowing through the energy storage device using the ramp signal,
wherein an increase in a magnitude of the feedback current causes a decrease in the duty cycle,
wherein a decrease in the magnitude of the feedback current causes an increase in the duty cycle, and
wherein the ramp generator circuit comprises:
a reference current source;
an output node configured to:
receive an output of the reference current source and the feedback current, and
produce a charging current according to a sum of the output of the reference current source and the feedback current;
a ramp capacitor coupled to the output node; and
a discharge circuit coupled across the ramp capacitor and receiving a clock signal, the discharge circuit configured to discharge the ramp capacitor in response to the clock signal,
wherein the ramp capacitor is charged according to the charging current, and
wherein the ramp signal is produced at the output node.