A Single BJT Bandgap Reference With Frequency Compensation Exploiting Mirror Pole

In this article, we propose a bandgap reference (BGR) with a single bipolar junction transistor (BJT) branch and a proportional-to-absolute-temperature (PTAT)-embedded amplifier. Having fewer BJT and passive components, the proposed BGR uses less power and area compared to the conventional BGR that uses multiple BJTs and resistors. As the proposed BGR achieves temperature compensation by employing a feedback loop that has two gain stages, frequency compensation is required. We propose frequency compensation scheme where a compensation capacitor is connected between the BGR output and a current mirror node in the PTAT-embedded amplifier. By using this scheme, location of a mirror pole associated with the current mirror node can be optimized to achieve both improved stability and low power consumption. Fabricated in 0.18-
$\mu \text{m}$
CMOS, the proposed BGR achieves temperature coefficient of 26.3 ppm/°C over −40 °C–140 °C; voltage accuracy (
$\sigma /\mu $
) of 0.33%; and power supply rejection (PSR) of −52 dB, −44 dB at 100 Hz, 1 MHz respectively; while occupying 0.0082 mm
²
and consuming 192 nW without startup circuit and trimming.