Patent ID: 8823380

Claim:
A device comprising: an array of chemically-sensitive field-effect transistors (chemFETs), chemFETs in the array including a source terminal and a drain terminal, and a floating gate coupled to a passivation layer; a plurality of column lines and a plurality of row lines coupled to chemFETs in the array of chemFETs; and circuitry coupled to the plurality of column lines and the plurality of row lines for reading a selected chemFET coupled to a selected column line and a selected row line, the circuitry comprising: bias circuitry to apply a read voltage to the selected row line during a read interval; and charge pump circuitry comprising: a plurality of capacitors; a first set of switches responsive to a first switching signal to connect the plurality of capacitors in parallel to sample a voltage level on the selected column line at a circuit node during a first stage of the read interval; and a second set of switches responsive to a second switching signal to connect the plurality of capacitors in series to amplify the sampled voltage level at the circuit node during a second stage of the read interval.