Ladder Type Network & its equivalent resistance ◉ Chapter: Current Electricity

◉ Chapter: Current Electricity 01 : ◉ Topic: Find the equivalent resistance of infinite ladder type network ...

A resistor ladder is an electrical circuit made from repeating units of resistors. Two configurations are discussed below, a string resistor ladder and an R–2R ladder.

An R–2R ladder is a simple and inexpensive way to perform digital-to-analog conversion, using repetitive arrangements of precise resistor networks in a ladder-like configuration. A string resistor ladder implements the non-repetitive reference network.

A string of many, often equally dimensioned, resistors connected between two reference voltages is a resistor string ladder network. The resistors act as voltage dividers between the referenced voltages. Each tap of the string generates a different voltage, which can be compared with another voltage: this is the basic principle of a flash ADC (analog-to-digital converter). Often a voltage is converted to a current, enabling the possibility to use an R–2R ladder network.

Disadvantage: for an n-bit ADC, the number of resistors grows exponentially, as {\displaystyle 2^{n}}2^{n} resistors are required, while the R–2R resistor ladder only increases linearly with the number of bits, as it needs only {\displaystyle 2n}2n resistors.
Advantage: higher impedance values can be reached using the same number of components.A network consisting of circuit elements connected in series and in parallel. The circuit elements may be resistors, inductance coils, or capacitors. A ladder network may be described as a cascade connection of a series of symmetrical T-section or pi-section four-terminal networks.