AN99-12

The AN99-12 is a High Speed, High performance Hysteretic Mode controller. It is part of a two chip solution, with the AN99-12 Smart Driver, providing power to advanced microprocessors. It uses a Dynamic Set Pointswitching technique along with an ultra-fast comparator to provide the control signal to an external high speed Mosfet driver. A 5-bit DAC sets the output voltage, thus providing a voltage resolution of 25mV.

AN99-12 has two on-chip linear regulators which drive external PNP transistors with output
voltage settings of 1.5V and 2.5Vdc. The linear regulator drivers have a separate soft start. A PWRGD TTL level signal is asserted when all voltages are within specifications. The part features Low Battery Detect and Undervoltage Lock-Out for the main Hysteretic controller to assure V-DC is within acceptable limits. An Over-Current comparator disables the main controller during an overcurrent condition using an externally programmable threshold.