Resistor networks have several key advantages over discrete devices. They reduce the system board area required to mount resistor devices, they increase system reliability (lower number of interconnects) and simplify the system manufacturing process.
Film technology (thick and thin film) is used to manufacture the majority of resistor network devices. In general thin film technology tends to be used in precision, low power applications with thick film reserved for higher power and higher resistor value applications. In resistor network applications where transient overvoltage and current are an issue, thick film is the preferred choice.
Resistor networks are used extensively in simple applications such as pull up/pull down resistors and terminating resistors where resistor tolerance and the impact of a change in one resistor value in relation to another is not important. In these applications, the resistors in the network array all tend to have the same value.
Specialist resistor design and manufacturing expertise is required where resistor matching is a key issue or resistors of various values are required on the same resistor network substrate. Resistor networks tend to be available in single in line and dual in line packages.
Matched resistors are used in a variety of applications including voltage dividers and adder/subtractor circuits. In these applications change in the value of one resistor in relation to another in response to some environmental input cannot be tolerated.
Matching the resistor devices Temperature Coefficient of Resistance (TCR) is crucial in most applications to minimise the impact of changes in ambient temperature. In power applications matching the Power Coefficient of Resistance (PCR) is also important.
In some specialist applications, there may be no choice but to use a network of several resistors of varying values on the same network resistor substrate. The design and manufacturing process for these application specific devices can be complex particularly if there is a wide variance in resistor values.
Custom resistor network devices tend to be required in low to medium volume which often means they are not of interest to the major manufacturers. However, specialist resistor manufacturers focussed on the application specific marketplace can often help.