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TLV8801, TLV8802

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SNOSD34 – AUGUST 2016

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Device Functional Modes (continued)

When possible, use AC coupling and AC feedback to reduce static current draw through the feedback elements.

Use film or ceramic capacitors since large electolytics may have large static leakage currents in the nanoamps.

7.4.4 Driving Capacitive Load

The TLV880x is internally compensated for stable unity gain operation, with a 6 kHz typical gain bandwidth.

However, the unity gain follower is the most sensitive configuration to capacitive load. The combination of a

capacitive load placed directly on the output of an amplifier along with the amplifier’s output impedance creates a

phase lag, which reduces the phase margin of the amplifier. If the phase margin is significantly reduced, the

response will be under damped which causes peaking in the transfer and, when there is too much peaking, the

op amp might start oscillating.

Figure 37. By using this isolation resistor, the capacitive load is isolated from the amplifier’s output. The larger

Figure 37. Resistive Isolation Of Capacitive Load