A Sub-1 ppm/°C Bandgap Voltage Reference With High-Order Temperature Compensation in 0.18-μm CMOS Process

This paper presents a high-precision bandgap voltage reference (BGR) with high-order temperature compensation. The compensation signal is generated by using both strong-inversion MOSFETs and Bipolar Junction transistors (BJTs), which cancels the high-order nonlinear term
$T\ln (T)$
in the BJT base-emitter voltage (V
_BE
), and thus a low temperature coefficient (TC) over a wide temperature range is achieved. The proposed BGR circuit is fabricated in a 0.18-
$\mu \text{m}$
CMOS process with an active area of
$0.256 m{m^{2}}$
and a max power consumption of 1.35 mW. A minimum TC of 0.706
${\mathrm{ppm}}/{}^ \circ C$
from
$- 25\,\,{}^ \circ C$
to 125
${}^ \circ C$
is achieved after an 8-bit resistance trimming. The line sensitivity is 0.0146%/V operating from 3.2 V to 3.7 V. The BGR achieves a power supply rejection (PSR) of −63.4 dB and a noise spectrum density of
$0.92 ~\mu \text{V}/\sqrt {Hz} $
at 10 Hz.