Download Rui Bai

Survey
yes no Was this document useful for you?
   Thank you for your participation!

* Your assessment is very important for improving the work of artificial intelligence, which forms the content of this project

Document related concepts

Power inverter wikipedia, lookup

Flexible electronics wikipedia, lookup

Pulse-width modulation wikipedia, lookup

Immunity-aware programming wikipedia, lookup

Three-phase electric power wikipedia, lookup

Thermal runaway wikipedia, lookup

Decibel wikipedia, lookup

Islanding wikipedia, lookup

Electrical ballast wikipedia, lookup

History of electric power transmission wikipedia, lookup

Electrical substation wikipedia, lookup

P–n diode wikipedia, lookup

Transistor wikipedia, lookup

Rectifier wikipedia, lookup

Distribution management system wikipedia, lookup

Current source wikipedia, lookup

Integrating ADC wikipedia, lookup

Triode wikipedia, lookup

Multimeter wikipedia, lookup

Power electronics wikipedia, lookup

Ohm's law wikipedia, lookup

Spark-gap transmitter wikipedia, lookup

Rectiverter wikipedia, lookup

Buck converter wikipedia, lookup

Schmitt trigger wikipedia, lookup

Switched-mode power supply wikipedia, lookup

Voltage regulator wikipedia, lookup

Alternating current wikipedia, lookup

Opto-isolator wikipedia, lookup

Resistive opto-isolator wikipedia, lookup

Stray voltage wikipedia, lookup

Surge protector wikipedia, lookup

Current mirror wikipedia, lookup

Voltage optimisation wikipedia, lookup

Mains electricity wikipedia, lookup

Transcript
Name: Rui Bai
Thesis Title: Effects of Non-ideal Characteristics of BJT on Band Gap Reference Circuits
Abstract:
In advanced integrated circuit design, it requires an accurate on-chip band gap reference
for optimal system performance. Precision band gap voltage references are an essential building
block in analog integrated circuits design. Band gap reference circuit produces a stable reference
voltage, which is insensitive to variation in voltage supplies and temperature. Band gap reference
circuits are commonly used in many applications such as analog to digital data converters, digital
to analog data converters and power management ICs. The increasing demand of higher accuracy
and complexities in IC applications put more and more stringent design requirements of band
gap reference circuits over process and temperature.
In a typical band gap reference circuit the non-ideal characteristics of PNP BJT can cause
inaccuracies in the reference voltage. In a typical bipolar transistor fabrication process, diffusion
is used to create the base region. The characteristics of BJT are strongly affected by the diffused
base region. The base region is very thick which contains a large parasitic resistance called base
spreading resistance. The BSR will cause a base-emitter voltage drop in BJT and the collector
current will vary due to this voltage change. A mathematical analysis of kuijk band-gap
reference circuit is presented in chapter II. However, the non-ideal characteristics of BJT have
not been addressed in the analysis. The following sections will discuss those non-ideal
characteristics of BJT. Besides the non-ideal characteristics of the BJT, the temperature
dependence of resistors will also affect the reference voltage significantly. The effects illustrated
in chapter III, which shows that by including the temperature dependence of the three resistors,
the inflection point of voltage reference will shift to a lower temperature and the sensitivity of
the reference voltage will be increased from 22.7
to 47.32
. Chapter IV shows the
temperature dependence of beta, which causes the inflection point to shift to a much higher
temperature and the sensitivity of the reference voltage will be increased from 22.7
45.5
to
. At the same time a large area BJT will have an apparent base-emitter voltage
variation due to the base spreading resistance. As shown in chapter V, the BSR will cause the
reference voltage increasing by about 10mV at a temperature range of -40
to 100
calibration and different layout of BJT will be discusses in chapter VI and chapter VII.
. Finally,