| US 7,612,543 B2 | ||
| Current mode PWM boost circuit and feedback signal sensing method thereof | ||
| Chien Peng Yu, Hsinchu (Taiwan); Yi Cheng Wang, Hsinchu (Taiwan); and Ye Hsuan Yan, Hsinchu (Taiwan) | ||
| Assigned to Advanced Analog Technology, Inc., Hsinchu (Taiwan) | ||
| Filed on Feb. 01, 2007, as Appl. No. 11/670,038. | ||
| Claims priority of application No. 95135493 A (TW), filed on Sep. 26, 2006. | ||
| Prior Publication US 2008/0074089 A1, Mar. 27, 2008 | ||
| Int. Cl. G05F 1/46 (2006.01) | ||
| U.S. Cl. 323—222 [323/287; 323/288] | 17 Claims |
| 10. A current mode PWM circuit comprising:
a boost unit comprising a boost inductor and a switch, said boost unit being configured to increase voltage to generate a
DC output voltage;
a voltage dividing circuit configured for generating a divided voltage from said DC output voltage;
an error amplifier configured to generate an error signal by comparing a reference voltage with said divided voltage;
a comparator configured to generate a first signal by comparing said error signal with a feedback signal;
a pulse width generator configured to receive said first signal and a second signal, said second signal coming from an oscillator
to generate a third signal, wherein said third signal is configured to control said switch; said
a feedback signal generating unit coupled to said boost unit to generate said feedback signal, wherein said feedback signal
comprises an equivalent inductor current signal flowing through said boost inductor and an equivalent slope compensation ramp
signal, said feedback signal generating unit comprising:
a capacitor having a terminal coupled to a connection point of said boost inductor and said switch; and
a current source coupled to another terminal of said capacitor.
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