The voltage regulator consists of a differential amplifier, pass transistor and resistor's divider. Differential amplifier compares reference voltage with voltage from a feedback divider and adjusts the impedance of a PMOS transistor for stabilization of output voltage at a set level. The output voltage adjustment is defined by the trimming code trim<5:0>. The block has low supply current and allows high current load.
The LDO can operate in two modes: “Normal” and “Economy”. “Economy” mode is introduced to save battery power. Although the mode may handle full current load, it has slower reactions on load current change. “Normal” mode is a default LDO mode with minimum response time on load change.
“Bypass” mode is a LDO mode of the pass transistor with minimum channel resistance, independently of the output signal of the differential amplifier.
The block is designed on Global Foundries CMOS 55 nm technology.