8-Pin N-FET Linear Regulator Controller
• On Board Charge Pump to Drive
• Input Voltage as Low as 3V
• Duty Ratio Mode Over Current
• Extremely Low Dropout Voltage
• Low External Parts Count
• Output Voltages as Low as 1.5V
The UCC3837 Linear Regulator Controller includes all the features re-
quired 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 pro-
viding an efficient linear solution for custom processor voltages, bus ter-
mination 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.
SLUS228A - AUGUST 1999