Abstract: A bandgap apparatus includes an error amplifier; a bandgap core including 2 BJT devices and core resistors for proportional to absolute temperature (PTAT) and complementary to absolute temperature (CTAT) current generations; a reference resistor for reference voltage generation; an NMOS current mirror having NMOS devices; a PMOS current mirror having PMOS devices; and 4 switches for controlling operation in a high-power mode or a low-power mode, wherein the high-power mode consumes more power than the low-power mode, wherein the error amplifier is switched on and the NMOS current mirror is switched off in the high-power mode, or the error amplifier is switched off and the NMOS current mirror is switched on in the low-power mode.

Abstract: An apparatus includes a poly current generator circuit, which includes a fractional bandgap circuit, or a bandgap voltage reference circuit and a current reference generator, an adaptive bias current generator, a frequency generator to generate an output clock signal having a select frequency, wherein the frequency generator includes a current starved ring oscillator that comprises n identical cascaded stages connected in a shape of a ring, wherein an output of the nth cascaded stage is fed back as an input of the first cascaded stage, wherein n is an odd number greater than or equal to 3; and clock buffers configured to buffer the output clock signal generated by the frequency generator for distribution.