Element Superposition Based Efficient PGA Gain Step Testing
Original Publication Date: 2004-Oct-25
Included in the Prior Art Database: 2004-Oct-25
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The gains in programmable gain amplifier (PGA) circuits are achieved by implementing a network of elements (e.g. resistors, capacitators or current sources) and switches. By changing the configuration of the switches (on/off) the individual gain settings can be applied. The total number of switch settings is 2n, with n being the number of switches. Up to now, for testing the device every single switch setting is programmed and the analog output (the gain) is measured to verify functionality and accuracy. So the amount of time required to test the device increases linearly with the number of gain settings and therefore exponentially with the number of switches. For complex PGAs with many settings the test costs can rise considerably. Sometimes the test costs are being reduced by measuring only a few or even just one gain setting. Hence the device is not fully checked.