8.2.3 Precision Reference Buffer

The TLVx197-Q1 feature high output-current-drive capability and low input offset voltage, making the device an excellent reference buffer to provide an accurate buffered output with ample drive current for transients. For the 10-µF ceramic capacitor shown in Figure 44, R_ISO, a 37.4-Ω isolation resistor, provides separation of two feedback paths for optimal stability. Feedback path number one is through R_F and is directly at the output (V_OUT). Feedback path number two is through R_Fx and C_F and is connected at the output of the op amp. The optimized stability components shown for the 10-µF load give a closed-loop signal bandwidth at V_OUT of 4 kHz and still provide a loop gain phase margin of 89°. Any other load capacitances require recalculation of the stability components: R_F, R_Fx, C_F, and R_ISO.

Figure 44. Precision Reference Buffer