A Sub-1-V Low-Noise Bandgap Voltage Reference

Abstract

A new sub-1-V bandgap voltage reference is presented in this paper, which has advantages over the prior arts in terms of output noise and compatibility with several fabrication processes. The topology allows the reference to operate with a supply voltage as low as 1 V by employing the reverse bandgap voltage principle (RBVP). It also has an attractive low-noise output without the use of a large external filtering capacitor. The design was fabricated with a 0.5-m BiCMOS process, but it is compatible with most CMOS and BiCMOS fabrication processes. The entire die area is approximately 0.4 mm 2 , including all test pads and dummy devices. Theoretical analysis and experimental results show that the output noise spectral density is 40 nV Hz with a bias current of 20 A. Moreover, the peak-to-peak output noise in the 0.1-10 Hz band is only 4 V. The untrimmed reference has a mean output voltage of 190.9 mV at room temperature, and it has a temperature coefficient in the 40 C to +125 C range of 11 ppm C (mean) with a standard deviation of 5 ppm C.Index Terms-BiCMOS, low noise, low voltage, noise measurement, peak-to-peak noise, sub-1-V bandgap voltage reference, temperature coefficient, 1-V supply.

Design of sub-1-V CMOS bandgap reference circuit using only one BJT

“…Our proposed circuits are based on the concept of reverse bandgap voltage principle (RBVP) [8,9] and which adds a scaled (attenuated) V EB voltage to the PTAT voltage to generate scaled version of the bandgap; an approach different from the CM technique used in [2] to generated scaled bandgap voltages. The output reference voltage, thus, is given as…”

“…This may be a problem for some technologies where only vertical PNP transistors with collectors connected to ground are available. Moreover, as pointed in [9] vertical NPN transistor in twin well process also creates a parasitic PNP transistor which starts operating in forward active region when the NPN transistor is saturated. (2) A more serious problem is the effect of finite (and low) b (ratio of collector current and base current) of the BJTs on the output reference voltage.…”

CMOS voltage reference based on threshold voltage and thermal voltage

“…The start up circuit shown in Fig. 1(c) provides the initial current until the voltage reference circuit reaches a suitable operating condition [14]. When the supply voltage is turned on, V S voltage is equal to ground and thus turns MS1 on.…”

Mutual Compensation of Threshold Voltage and Thermal Voltage Temperature Effects with Applications in Voltage Reference Generator

“…For this purpose, many kinds of voltage reference circuits are proposed. For example, some advanced bandgap voltage reference based on parasitic bipolar transistor have lower power consumption than the traditional bandgap reference are invented [2,3], but they are not performs satisfactorily because of the parasitic bipolar transistor in a standard CMOS process is usually not very well characterized. Meanwhile, many nanopower voltage reference circuits based on the fact that the threshold voltage of MOSFETs with different gate oxide thickness in the same CMOS technology exhibit different temperature characteristic are proposed [4,5,6,7], but such solutions also can not be implemented in a standard CMOS technology because they require additional fabrication steps.…”