250iHP_PMU_03 is power management system, which divided in primary unit and up to three secondary units. Primary unit includes bandgap reference voltage source and its buffered version, low drop out voltage regulator with output voltage 2.5V and reference current source together with set of current mirrors to provide reference current. Secondary units include bandgap reference voltage source, low drop out voltage regulator with output voltage 2.5V and set of current mirrors, which take reference current from primary part current mirrors.
The voltage regulator contains an error amplifier, a PMOS power transistor and resistors for setting output voltage. Error amplifier compares input reference voltage with voltage from feedback resistor divider and adjusts the impedance of the pass PMOS transistor for stabilization of output voltage at the targeted level.
Bandgap reference voltage source forms temperature and power supply variations independent voltage.
Reference current sources provide stable output currents, which are independent of voltage/temperature variations, if external resistor is used (PMU_RS_CS = “0”). Reference current sources are dependent on internal resistor rppd PVT corner, if PMU_RS_CS = “1”.