PT2201

PT2201 Current Mode PWM Controller GENERAL DESCRIPTION PT2201 is a highly integrated current mode PWM controller, with the features of extreme low start up current, low operating current plus green mode operation and built-in protection functions allows the design of SMPS become easier to meet the high performance, high reliability and low standby power requirements. The start-up current is very small typically 3uA so that a large start up resistor can be used in the start-up circuit to minimize standby power. Under the light load or no load conditions the PT2201 automatically decreases PWM frequency and enters burst mode operation thus the power loss on power MOSFET is reduced. With a programmable oscillator the PWM frequency is easily set via an external resistor. Synchronized slope compensation has been implemented in the PT2201 to avoid potential sub harmonic oscillation caused by peak current control mode when operating under Continuous Conduct Mode. Moreover, the internal LEB on the current sense input removes the signal glitch due to snubber circuit diode reverse recovery and greatly reduces the external component count and system cost in the design. The PT2201 also features multi-level protections to enhance SMPS reliability including cycle by cycle Over Current Protection, Over Load Protection, programmable Over Û w Vm `RyÑb € FEATURES z z z z z z z z z z Frequency Jittering For Better EMI Performance Frequency automatically decrease to minimize standby power Noise...