CS52845

CS52845 CS52845 Current Mode PWM Control Circuit with 50% Max Duty Cycle Description The CS52845 provides all the necessary features to implement offline fixed frequency current-mode control with a minimum number of external components. The CS52845 incorporates a new precision temperature-controlled oscillator to minimize variations in frequency. An internal toggle flipflop, which blanks the output every other clock cycle, limits the duty-cycle range to less than 50%. An undervoltage lockout ensures that VREF is stabilized before the output stage is enabled. In the CS52845 turn on is at 8.4V and turn off at 7.6V. Other features include low start-up current, pulse-by-pulse current limiting, and a high-current totem pole output for driving capacitive loads, such as gate of a power MOSFET. The output is low in the off state, consistent with N-channel devices. Features s Optimized for Off-line Control s Temperature Compensated Oscillator s 50% Maximum Duty-cycle Clamp s VREF Stabilized before Output Stage is Enabled s Low Start-up Current s Pulse-by-pulse Current Limiting s Improved Undervoltage Lockout s Double Pulse Suppression s 1% Trimmed Bandgap Reference s High Current Totem Pole Output Absolute Maximum Ratings Supply Voltage (ICC<30mA) ..........................................................Self Limiting Supply Voltage (Low Impedance Source)...................................................30V Output Current ..............................................................