ZHCSSM5D May 1999 – February 2024 LM7171
PRODUCTION DATA
6.3.3 Driving Capacitive Loads
Amplifiers driving capacitive loads can oscillate or have ringing at the output. To eliminate oscillation or reduce ringing, place an isolation resistor as shown in Figure 6-9. The combination of the isolation resistor and the load capacitor forms a pole to increase stability by adding more phase margin to the overall system. The desired performance depends on the value of the isolation resistor; the bigger the isolation resistor, the more damped the pulse response becomes. For LM7171, a 50Ω isolation resistor is recommended for initial evaluation. Figure 6-10 shows the LM7171 driving a 150pF load with the 50Ω isolation resistor.
Figure 6-9 Isolation Resistor Used to
Drive Capacitive Load
Figure 6-10 The LM7171 Driving a 150pF
Load With a 50Ω Isolation Resistor