LMC6034 Datasheet, PDF (5/12 Pages) National Semiconductor (TI) – CMOS Quad Operational Amplifier

Typical Performance Characteristics V_S = ±7.5V, T_A = 25˚C unless otherwise specified (Continued)
Output Characteristics
Current Sourcing
Input Voltage Noise
vs Frequency
CMRR vs Frequency
DS011134-27
Open-Loop Frequency
Response
DS011134-28
Frequency Response
vs Capacitive Load
DS011134-29
Non-Inverting Large Signal
Pulse Response
Stability vs
Capacitive Load
DS011134-30
Stability vs
Capacitive Load
DS011134-31
DS011134-32
DS011134-33
DS011134-34
Note: Avoid resistive loads of less than 500Ω, as they may cause instability.
Applications Hint
Amplifier Topolgy
The topology chosen for the LMC6034, shown in Figure 1, is
unconventional (compared to general-purpose op amps) in
that the traditional unity-gain buffer output stage is not used;
instead, the output is taken directly from the output of the in-
tegrator, to allow a larger output swing. Since the buffer tra-
ditionally delivers the power to the load, while maintaining
high op amp gain and stability, and must withstand shorts to
either rail, these tasks now fall to the integrator.
As a result of these demands, the integrator is a compound
affair with an embedded gain stage that is doubly fed forward
(via C_f and Cff) by a dedicated unity-gain compensation
driver. In addition, the output portion of the integrator is a
push-pull configuration for delivering heavy loads. While
sinking current the whole amplifier path consists of three
gain stages with one stage fed forward, whereas while
sourcing the path contains four gain stages with two fed
forward.
5
www.national.com