OPA336NA3K Datasheet, PDF (8/24 Pages) Texas Instruments – SINGLE-SUPPLY, microPower CMOS OPERATIONAL AMPLIFIERS microAmplifier ™ Series

accuracy. For example, with R_L = 25kΩ, OPA336 series op
amps perform well with capacitive loads in excess of 1000pF,
as shown in Figure 4. Without R_S, capacitive load drive is
typically 350pF for these conditions, as shown in Figure 5.
R_S = 100Ω, Load = 2kΩ || 1000pF, V_S = +5V
Direct Current (DC) error at the output; however, this error
may be insignificant. For instance, with R_L = 100kΩ and
R_S = 100Ω, there is only about a 0.1% error at the output.
Figure 5 shows the recommended operating regions for the
OPA336. Decreasing the load resistance generally improves
capacitive load drive. Figure 5 also illustrates how stability
differs depending on where the resistive load is connected.
With G = +1 and R_L = 10kΩ connected to V_S/2, the OPA336
can typically drive 500pF. Connecting the same load to
ground improves capacitive load drive to 1000pF.
50µs/div
FIGURE 4. Small-Signal Step Response Using Series Re-
sistor to Improve Capacitive Load Drive.
Alternatively, the resistor may be connected in series with
the output outside of the feedback loop. However, if there is
a resistive load parallel to the capacitive load, it and the
series resistor create a voltage divider. This introduces a
10k
Operation Above Selected Gain
Curve Not Recommended
G = +1
R_L to Ground
G = +2
R_L to Ground
1k
100
5
G = +1
R_L to V_S/2
V_S = +5V, V_O = V_S/2
10
100
Resistive Load (kΩ)
FIGURE 5. Stability—Capacitive Load vs Resistive Load.
8
OPA336, 2336, 4336
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