PGA functioning at High power, High Opamp Bias


Question: Will PGA function at High power , High Opamp bias ?

Respone: The opamp is not guaranteed to run properly at high power and high bias at 3.3V; we run out of bias headroom and the opamp loses voltage swing capability. For this reason, we limit operation to Power, Bias = L,L; L,H; M,L; M,H; H,L for 3.3V. The principal effect of PGA operating current is bandwidth. You can see graphs of bandwidth for Power, Bias = H,H and M,H in the user module data sheet. The performance at H,L is between M,H and H,H; and is essentially independent of operating voltage. The -3dB bandwidth of the PGA at maximum gain is very close to 100 kHz at Power, Bias = H,L. At unity gain it is well over 1.0 MHz.