A 2.6 ppm/°C 2.5 V Piece-Wise Compensated Bandgap Reference with Low Beta Bipolar

Abstract

Traditional bandgap reference (BGR) is sensitive to process variation and is not suitable for mass production. Consequently, a stacked piece-wise compensated bandgap reference (SPWBGR) with low beta bipolar is proposed, designed and fabricated in the 0.18 μm high-voltage (HV) BCD process. Two stacked BGR (SBGR) cores make up the proposed BGR circuit. Through setting the target reference voltage near the output voltage of SBGR cores, the feedback resistor ratio is reduced and the base current side-effect is significantly decreased. Notably, the SBGR core is implemented by the low beta npn bipolar and it relaxes the requirement for the high beta bipolar. The two SBGR cores are almost identical except for the temperature slope and feedback ratio. The two cores have different zero temperature coefficient (TC) points, one is set at −5 °C, and the other is set at 60 °C, named as SBGRA and SBGRB, respectively. The SBGRA and SBGRB output the same voltage at their zero TC point. The higher voltage of SBGRA and SBGRB is the output voltage. Through the process of tracking the maximum value of different SBGR cores, the proposed SPWBGR achieves 2.6 ppm/°C TC from −40 to 100 °C. As a result, the average TC for five random samples is 5.3 ppm/°C. The line regulation is 2 mV/V from 4.5 to 5.5 V power supply. The current consumption is 6.8 µA. The active area of the proposed BGR is 0.075 mm2.

A 3.95 ppm/°C 7.5 μW Second-Order Curvature Compensated Bandgap Reference in 0.11 μm CMOS

“…The resolution and conversion speed of these circuit modules are significantly impacted by the precision of the BGR circuit; in addition, the life of these circuit modules is impacted by the power consumption. However, conventional BGR circuits have shortcomings in terms of accuracy and power consumption [1][2][3].…”

A Fully-Integrated 180 nm CMOS 1.2 V Low-Dropout Regulator for Low-Power Portable Applications

“…Therefore, any dependence on the temperature and/or the battery voltage in V ref is transferred to V out . This voltage reference is typically implemented as a bandgap voltage reference with a combination of complementary to absolute temperature (CTAT) and proportional to absolute temperature (PTAT) voltages or currents to provide a reliable temperature and supply independent solution [33][34][35][36][37][38]. However, the classical approaches typically provide higher values than the low-voltage 0.4 V approach herein adopted, while usually demanding high levels of power and area consumption not suitable for miniaturized portable systems.…”

A low‐power NPN‐based band‐gap voltage reference in an ultra‐wide temperature range

“…Due to the influence of base current, I B , the BGR output, V REF has an additional error term, as shown in (7).…”

“…Figure 5 shows a further improvement using stacked NPNs for V REF ≥ 2V BG . By setting a smaller feedback ratio between R D1 and R D2 with the same output voltage in Figure 4, the side-effect of the base current on the temperature coefficient (TC) is significantly reduced [7]. Ignoring the base current, the V REF is given by (8).…”