High-Accuracy Power On Chip Research And Implementation

Power management is necessary to reduce the standby power of portable applications such as cellular phones and PDAs. The linear regulator is one of the most popular power converters widely used in power management. It is especially suitable for applications that require low-noise and precision supply voltages with few off-chip components. With the rapid development of system-on-chips designs, there is a growing trend toward power-management integration. On-chip and local LDOs are utilized to power up sub-blocks of a system individually, and this can significantly reduce crosstalk, improve the voltage regulation, and eliminate load-transient voltage spikes from the bond-wire inductances. In addition, system-on-chip designs with on-chip and local LDOs can reduce both board space and external pins significantly.Due to the emerging need of high-performance references and LDOs for low-power, high-speed, high-precision mixed-signal systems, this paper presents the detailed analysis of the voltage-reference, reference-buffer, cap-free LDO circuit architectures and their various performance including loop stability, offset, noise, PSR(Power Supply Rejection), start up. For the application of a low-power, high-speed, high-accuracy pipelined-SAR ADC and a smart temperature sensor, two chips are designed and measured. The specific contributions of this work include:1. A system analysis method of the device noise and PSR (Power Supply Rejection) is proposed. Based on it, some techniques are used in op-amp, bandgap, LDO to improve these performances.2. Using replica source follow to achieve the requirement of the reference of the high-speed high-accuracy ADC.3. It gives a detailed analysis of several different structures bandgap with op-amp, and discusses the choice in different applications.