| 主权项 |
1. A switch-mode power supply controller configured to generate a switch control signal to drive a primary switch, the switch-mode power supply controller comprising:
an on-time controller, receiving a sensed signal indicative of a current on the primary switch, and generating a switch-off signal, wherein the switch-off signal is configured to switch OFF the primary switch when the sensed signal arrives at the same level as a threshold signal indicative of a peak current, and wherein the switch-off signal is utilized to determine an on-time of the primary switch; an off-time controller, receiving a feedback error signal and the switch control signal, and generating a switch-on signal configured to switch ON the primary switch, wherein the switch-on signal is utilized to determine an off-time of the primary switch; a switch control signal generator, receiving the switch-off signal and the switch-on signal, operable to generate the switch control signal; and a jittering signal generator, generating a first jittering signal, wherein the jittering signal generator is coupled to either the on-time controller or the off-time controller, and wherein the first jittering signal is utilized to jitter the on-time or the off-time of the primary switch; wherein the off-time controller further comprises a frequency capacitor, a comparator and a constant current source, wherein a charging current charges the frequency capacitor when the switch control signal is set to turn the primary switch OFF, and wherein the comparator is configured to switch ON the primary switch when the voltage level across the frequency capacitor arrives at the level of the feedback error signal, and further wherein the constant current source is configured to generate a constant current, wherein the charging current comprises the constant current. |
