Method and apparatus for measuring sheet resistance

摘要

A resistance measurement circuit includes a plurality of current sources, a plurality of resistor strings and a comparator. Each resistor string is coupled in series with a respective one of the current sources and includes a plurality of nodes with different resistances relative to a reference node. Each node in each resistor string has a different resistance relative to the reference node than corresponding nodes in the other resistor strings. The comparator has a first comparison input coupled to a reference voltage and a second comparison input selectively coupled to the plurality of nodes in each resistor string.