Adjustment of the temperature dependence of the output voltage of a band gap circuit is achieved by intentionally mismatching currents flowing through nodes coupled to the inputs of an amplifier. Each node is coupled to a bipolar junction transistor and a resistor, such that an output voltage of the band gap circuit varies due to the temperature dependence of currents through the bipolar junction transistors and the temperature dependence of currents flowing through the resistors. Networks of parallel metal oxide semiconductor transistors are coupled to each node, with one network including transistors that may be selectively switched into or out of the network to adjust the effective channel width for that network, thereby altering the ratio of effective channel widths and adjusting the temperature dependence of the band gap circuit's output voltage.