How is a bandgap voltage reference used in a circuit?
From Wikipedia, the free encyclopedia A bandgap voltage reference is a temperature independent voltage reference circuit widely used in integrated circuits. It produces a fixed (constant) voltage regardless of power supply variations, temperature changes, or circuit loading from a device.
Why are bandgap references important in IC design?
The other critical issue in design of bandgap references is power efficiency and size of circuit. As a bandgap reference is generally based on BJT devices and resistors, the total size of circuit could be large and therefore expensive for IC design.
Is the bandgap reference based on BJT devices?
As a bandgap reference is generally based on BJT devices and resistors, the total size of circuit could be large and therefore expensive for IC design. Moreover, this type of circuit might consume a lot of power to reach to the desired noise and precision specification.
What is the temperature drift of the bandgap voltage?
When summing a PTAT and a CTAT current, only the linear terms of current are compensated, while the higher-order terms are limiting the temperature drift (TD) of the bandgap reference at around 20 ppm/°C, over a temperature range of 100 °C.
Which is better a direct bandgap or an indirect band gap?
In contrast, for materials with an indirect band gap, a photon and phonon must both be involved in a transition from the valence band top to the conduction band bottom. Therefore, direct bandgap materials tend to have stronger light emission and absorption properties.
Why does the output of a bipolar bandgap vary?
The output of the bandgap reference will vary from chip to chip because of processing differences. The primary effect in bipolar bandgap references is the variation of resistors in the circuit. Absolute value of these resistors is controlled to 20% or even 50% by process parameters.