Figure 8-9 shows an ac-coupled, noninverting gain amplifier for single 5V supply operation. This circuit was used for ac characterization of the OPA698, with a 50Ω source (that matches) and a 500Ω load. The midpoint reference on the noninverting input is set by two 806Ω resistors. This configuration gives an input bias current-canceling resistance that matches the 402Ω DC source resistance seen at the inverting input (see Section 8.1.9). The power-supply bypass for the supply consists of two capacitors: one electrolytic 2.2µF and one ceramic 0.1µF. The power-supply bypass capacitors are shown explicitly in Figure 8-8 and Figure 8-9, but is assumed in the other figures. The limiter voltages (V_H and V_L) and the respective bias currents (I_VH and I_VL) have the polarities shown. These limiter voltages are adequately bypassed with a 0.1µF ceramic capacitor to ground. The single-supply circuit can use three resistors to set V_H and V_L, whereas the dual-supply circuit usually uses four resistors to reference the limit voltages to ground. While this circuit shows 5V operation, the same circuit can be used for single supplies up to 12V.

Figure 8-9 AC-Coupled, Single-Supply Amplifier