LM6161WG/883 National Semiconductor, LM6161WG/883 Datasheet - Page 7

• Manufacturer Part Number: LM6161WG/883
• Description: High Speed Operational Amplifier
• Manufacturer: National Semiconductor

Simplified Schematic
Applications Tips
The LM6361 has been compensated for unity-gain opera-
tion. Since this compensation involved adding emitter-
degeneration resistors to the op amp’s input stage, the
open-loop gain was reduced as the stability increased. Gain
error due to reduced A
thus, for gains between 5 and 25, the less-compensated
LM6364 should be used, and the uncompensated LM6365 is
appropriate for gains of 25 or more. The LM6361, LM6364,
and LM6365 have the same high slew rate, regardless of
their compensation.
The LM6361 is unusually tolerant of capacitive loads. Most
op amps tend to oscillate when their load capacitance is
greater than about 200 pF (especially in low-gain circuits).
The LM6361’s compensation is effectively increased with
load capacitance, reducing its bandwidth and increasing its
stability.
Power supply bypassing is not as critical for the LM6361 as
it is for other op amps in its speed class. Bypassing will, how-
Typical Applications
Offset Voltage Adjustment
DS009057-4
VOL
is most apparent at high gains;
7
ever, improve the stability and transient response and is rec-
ommended for every design. 0.01 µF to 0.1 µF ceramic ca-
pacitors should be used (from each supply “rail” to ground);
if the device is far away from its power supply source, an ad-
ditional 2.2 µF to 10 µF of tantalum may provide extra noise
reduction.
Keep all leads short to reduce stray capacitance and lead in-
ductance, and make sure ground paths are low-impedance,
especially where heavier currents will be flowing. Stray ca-
pacitance in the circuit layout can cause signal coupling
across adjacent nodes and can cause gain to unintentionally
vary with frequency.
Breadboarded circuits will work best if they are built using
generic PC boards with a good ground plane. If the op amps
are used with sockets, as opposed to being soldered into the
circuit, the additional input capacitance may degrade circuit
performance.
1 MHz Low-Pass Filter
DS009057-3
DS009057-10
www.national.com