TLV9352IDDFR datasheet(23/63 Pages) TI

23 / 63 page

7.3.5 Capacitive Load and Stability

The TLV935x features a resistive output stage capable of driving smaller capacitive loads, and by leveraging

an isolation resistor, the device can easily be configured to drive large capacitive loads. Increasing the gain

enhances the ability of the amplifier to drive greater capacitive loads; see Figure 7-5 and Figure 7-6. The

particular op amp circuit configuration, layout, gain, and output loading are some of the factors to consider when

establishing whether an amplifier is stable in operation.

Cap Load (pF)

500 1000 1500 2000 2500 3000 3500 4000 4500 5000

C008

RISO = 0 , Positive Overshoot

RISO = 0 , Negative Overshoot

RISO = 50 , Positive Overshoot

RISO = 50 , Negative Overshoot

Figure 7-5. Small-Signal Overshoot vs Capacitive

Load (100-mV Output Step, G = 1)

Cap Load (pF)

500 1000 1500 2000 2500 3000 3500 4000 4500 5000

C007

RISO = 0 , Positive Overshoot

RISO = 0 , Negative Overshoot

RISO = 50 , Positive Overshoot

RISO = 50 , Negative Overshoot

Figure 7-6. Small-Signal Overshoot vs Capacitive

Load (100-mV Output Step, G = –1)

For additional drive capability in unity-gain configurations, improve capacitive load drive by inserting a small (10

Ω to 20 Ω) resistor, RISO, in series with the output, as shown in Figure 7-7. This resistor significantly reduces

ringing and maintains DC performance for purely capacitive loads. However, if a resistive load is in parallel

with the capacitive load, then a voltage divider is created, thus introducing a gain error at the output and

slightly reducing the output swing. The error introduced is proportional to the ratio RISO / RL, and is generally

negligible at low output levels. A high capacitive load drive makes the TLV935x well suited for applications such

as reference buffers, MOSFET gate drives, and cable-shield drives. The circuit shown in Figure 7-7 uses an

isolation resistor, RISO, to stabilize the output of an op amp. RISO modifies the open-loop gain of the system for

increased phase margin. For additional information on techniques to optimize and design using this circuit, TI

Precision Design TIDU032 details complete design goals, simulation, and test results.

load

out

iso

-V

Figure 7-7. Extending Capacitive Load Drive With the TLV9351

www.ti.com

TLV9351, TLV9352, TLV9354

SBOS994E – NOVEMBER 2019 – REVISED JANUARY 2022

Submit Document Feedback

Product Folder Links: TLV9351 TLV9352 TLV9354

TLV9352IDDFR Datasheet(PDF) 23 Page - Texas Instruments

TLV9352IDDFR Datasheet(HTML) 23 Page - Texas Instruments

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63

Datasheet Download

Link URL