Johannes Gerber

An Ultra Low Power Bandgap Operational at Supply From 0.75 V

We present an ultra low power (200 nA current consumption) reverse bandgap voltage reference operational from supply voltages down to 0.75 V. The reference is a part of microprocessor system on chip implemented in a digital 130 nm CMOS process and has a total area of 0.07 mm2. The reference accuracy is ± 2.5% (5 sigma) over a temperature range of - 20 to 85°C without trimming. With trimming ± 0.5% accuracy is achieved.

Architectural and Circuit Design Techniques for Power Management of Ultra-Low-Power MCU Systems

A holistic power saving concept for ultra-low-power microcontroller (MCU) systems involving application requirements, system architecture, and circuit design techniques is presented. The key of this concept is a digitally enhanced low dropout regulator (LDO) supplying the MCU digital core. By making use of known system power information, the LDO digitally adapts its maximum current drive capability up to 2.56 mA while its quiescent current is as low as 650 nA in light load conditions. In this way, the power management overhead is drastically reduced when operating at low clock speeds enabling system energy savings of 31% at 1 MHz. At the same time, a drastic reduction of the LDO output capacitance enables ultra-low-power consumption during sleep and energy efficient wake-up, resulting in system energy savings up to a factor of 4.6.

An ultra low power bandgap operational at supply as low as 0.75V

We present an ultra low power (200nA consumption) reverse bandgap voltage reference operational from supply voltages as low as 0.75V. The reference is a part of a microcontroller system and has total area of 0.07 mm² implemented in a digital 130 nm CMOS process. Accuracy of ±1.5% (5 sigma) over temperature range −20 to 85°C without trimming and ±0.5% with trimming is achieved.