CS5124, CS5126 High Performance, Integrated Current Mode PWM Controllers The CS5124/6 is a fixed frequency current mode controller designed specifically for DC−DC converters found in the telecommunications industry. The CS5124/6 integrates many commonly required current mode power supply features and allows the power supply designer to realize substantial cost and board space savings. The product matrix is as follows: CS5124: 400 kHz w/VBIAS Pin, 195 mV first current sense threshold. CS5126: 200 kHz w/SYNC Pin, 335 mV first current sense threshold. The CS5124/6 integrates the following features: Internal Oscillator, Slope Compensation, Sleep On/Off, Undervoltage Lock Out, Thermal Shutdown, Soft−Start Timer, Low Voltage Current Sense for Resistive Sensing, Second Current Threshold for Pulse−by−Pulse overcurrent Protection, a Direct Optocoupler Interface and Leading Edge Current Blanking. The CS5124/6 has supply range of 7.7 V to 20 V and is available in 8 pin SOIC narrow package. Features • Line UVLO Monitoring • Low Current Sense Voltage for Resistive Current Sensing • External Synchronization to Higher or Lower Frequency Oscillator (CS5126 Only) • Bias for Startup Circuitry (CS5124 Only) • Thermal Shutdown • Sleep On/Off Pin • Soft−Start Timer • Leading Edge Blanking • Direct Optocoupler Interface • 90 ns Propagation Delay • 35 ns Driver Rise and Fall Times • Sleep Mode • Pb−Free Packages are Available