Solid state programmable voltage generators are subject to temperature dependent output errors. For example, the voltage generator may be formed on a silicon die and the generated voltage changes as the temperature of the die changes. These errors typically include a bow shaped error from a bandgap reference voltage, in addition to gain drift and offset drift errors from both the digital to analog converter (DAC) and output buffer typically used in these generators.
Conventional programmable voltage generators use one of several methods to reduce the bandgap bow error by incorporating temperature compensating circuitry within the bandgap circuit itself. However, these circuits may not completely correct for the effects of temperature and therefore some temperature related error may be included in the bandgap output. Offset and gain errors in the DAC and output buffer are typically trimmed at one temperature by using separate trim circuits. These trim circuits may be implemented using circuit elements that drift with temperature in an attempt to track any known temperature dependent offset or gain errors. Unfortunately, due to the above conditions, the output of conventional programmable voltage generators may still include temperature dependent errors. Thus, a more robust solution is desired.