What is trimming in circuits?

What is trimming in circuits?

trimming means fine tuning of a certain parameter, for example trimming a resistance means changing the value of the resistance with certain step to acheive the specs.

How does a bandgap voltage reference work?

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. This circuit concept was first published by David Hilbiber in 1964.

How do you calculate bandgap voltage?

VT=kTq

1. In this equation, k is the Boltzmann constant, q is the charge carried by a single electron, and T is temperature in Kelvin.
2. To solve this problem, we can amplify the thermal voltage by a temperature independent constant M so that Mkq M k q is equal to about 2 mV/°C.

What is voltage reference Why is it needed?

A voltage reference is a precision device specifically designed to maintain a constant output voltage, even as parameters such as ambient temperature or supply voltage change. The precision of a voltage reference enables its use in several differ- ent types of applications beyond a data converter.

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.

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.

What is the reference voltage for a laser trimming machine?

In addition to the time cost, Laser trimming machines are not cheap. The principle of the bandgap voltage reference is to balance the negative temperature coefficient (NTC) of a pn junction with the positive temperature coefficient (PTC) of the thermal voltage, Vt = kT/q.

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.