Data Sheet
(V
LOAD
)
RMS
= V
PEAK
/ √2
( I
LOAD
)
RMS
= ( V
LOAD
)
RMS
/ Rload
eff
The dynamic power is focused primarily within the output
stage driving the load. This value can be calculated as:
P
DYNAMIC
= (V
S+
- V
LOAD
)
RMS
× ( I
LOAD
)
RMS
Assuming the load is referenced in the middle of the pow-
er rails or V
supply
/2.
Figure 4 shows the maximum safe power dissipation in
the package vs. the ambient temperature for the pack-
ages available.
2.5
SOIC-16
2
C
L
(pF)
1nF
5nF
10nF
100
R
S
(Ω)
0
0
0
0
-3dB BW (kHz)
485
390
260
LM358, LM324
Low Power, 3V to 36V, Single/Dual/Quad Amplifiers
440
Table 1: Recommended R
S
vs. C
L
For a given load capacitance, adjust R
S
to optimize the
tradeoff between settling time and bandwidth. In general,
reducing R
S
will increase bandwidth at the expense of ad-
ditional overshoot and ringing.
Overdrive Recovery
An overdrive condition is defined as the point when either
one of the inputs or the output exceed their specified volt-
age range. Overdrive recovery is the time needed for the
amplifier to return to its normal or linear operating point.
The recovery time varies, based on whether the input or
output is overdriven and by how much the range is ex-
ceeded. The LM358/LM324 will typically recover in less
than 30ns from an overdrive condition. Figure 6 shows the
LM358 in an overdriven condition.
4
3.5
4
3.5
3
Input
Maximum Power Dissipation (W)
1.5
SOT23-6
1
0.5
SOT23-5
0
-40
-20
0
20
40
60
80
Ambient Temperature (°C)
Figure 4. Maximum Power Derating
V
IN
= 1.25V
pp
G=5
Driving Capacitive Loads
Increased phase delay at the output due to capacitive load-
ing can cause ringing, peaking in the frequency response,
and possible unstable behavior. Use a series resistance, R
S
,
between the amplifier and the load to help improve stability
and settling performance. Refer to Figure 5.
Input
+
-
R
f
R
g
R
s
C
L
R
L
Input Voltage (V)
3
2.5
2
1.5
1
0.5
0
-0.5
Output
Output Voltage (V)
2.5
2
1.5
1
0.5
0
-0.5
Rev 1A
Output
0
20
40
60
80
100
Time (us)
Figure 6. Overdrive Recovery
Figure 5. Addition of R
S
for Driving
Capacitive Loads
Table 1 provides the recommended R
S
for various capaci-
tive loads. The recommended R
S
values result in <=1dB
peaking in the frequency response. The Frequency Re-
sponse vs. C
L
plot, on page 6, illustrates the response of
the LM358/LM324.
©2011 CADEKA Microcircuits LLC
www.cadeka.com
11
CADEKA [ CADEKA MICROCIRCUITS LLC. ]
