36.1.1 OverviewA simplified block diagram for the USB Voltage Regulator module is shown below.STANDBYreg33_in reg33_outYesNoRUN RegulatorSTANDBY RegulatorVoltage RegulatorChipPowerSupplyRegulated OutputVoltageVoltage Regulator ESR: 5m -> 100m OhmsExternal Capacitortypical = 2.2uFOther ModulesFigure 36-2. USB Voltage Regulator Block DiagramThis module uses 2 regulators in parallel. In run mode, the RUN regulator with thebandgap voltage reference is enabled and can provide up to 120 mA load current. In runmode, the STANDBY regulator and the low power reference are also enabled, but aswitch disconnects its output from the external pin. In STANDBY mode, the RUNregulator is disabled and the STANDBY regulator output is connected to the external pin.Internal power mode signals control whether the module is in RUN or STANDBY mode.36.1.2 Features• Low drop-out linear voltage regulator with one power channel (3.3V).• Low drop-out voltage: 300 mV.• Output current: 120 mA.• Three different power modes: RUN, STANDBY and SHUTDOWN.• Low quiescent current in RUN mode.• Typical value is around 120 uA (one thousand times smaller than the maximumload current).• Very low quiescent current in STANDBY mode.• Typical value is around 1 uA.• Automatic current limiting if the load current is greater than 290 mA.IntroductionKL25 Sub-Family Reference Manual, Rev. 3, September 2012652 Freescale Semiconductor, Inc.
