The Realization and Application of Program-controlled Hardware Zero Adjustment Algorithm Based on PGA309

Based on the programmable gain amplifier chip PGA309´s Coarse Offset and zero Adjustment function, a set of algorithms is designed in this paper to implement the measurement system program-controlled hardware zero adjustment without having to manually adjust the multiturn potentionmeters or program-controlled adjust the digital potentionmeters, thus avoiding all kinds of shortcomings which exists with the potentiometer zero adjustment. The method can be used to compensate the input signal in ±59.5mV range approximately and promote the output zero above to 5V in the measurement systems which use PGA309 as amplifier and are powered by +5V, and thereby counteract an input signal zero in the maximal degree and ensure a stable and small final output zero to expand system´s dynamic input range and keep its signal resolution.