UCC3837

8-Pin N-FET Linear Regulator Controller UCC1837 UCC2837 UCC3837 FEATURES On Board Charge Pump to Drive External N-MOSFET Input Voltage as Low as 3V Duty Ratio Mode Over Current Protection Extremely Low Dropout Voltage Low External Parts Count Output Voltages as Low as 1.5V DESCRIPTION The UCC3837 Linear Regulator Controller includes all the features required for an extremely low dropout linear regulator that uses an external N-channel MOSFET as the pass transistor. The device can operate from input voltages as low as 3V and can provide high current levels, thus providing an efficient linear solution for custom processor voltages, bus termination voltages, and other logic level voltages below 3V. The on board charge pump creates a gate drive voltage capable of driving an external N-MOSFET which is optimal for low dropout voltage and high efficiency. The wide versatility of this IC allows the user to optimize the setting of both current limit and output voltage for applications beyond or between standard 3-terminal linear regulator ranges. This 8-pin controller IC features a duty ratio current limiting technique that provides peak transient loading capability while limiting the average power dissipation of the pass transistor during fault conditions. See the Application Section for detailed information. BLOCK DIAGRAM VDD 1 CS 8 CAP 2 140mV CHARGE PUMP CURRENT SENSE AMPLIFIER LEVEL SHIFT 5 VOUT ERROR AMPLIFIER 6 FB 100mV UVLO CURRENT SENSE COMPARATOR TI...