KM4120IT6TR3 Просмотр технического описания (PDF) - Fairchild Semiconductor
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KM4120IT6TR3 Datasheet PDF : 11 Pages
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KM4110/KM4120
DATA SHEET
General Description
The KM4110 is a single supply, general purpose, volt-
age-feedback amplifier fabricated on a complementary
bipolar process. The KM4110 offers 75MHz unity gain
bandwidth, 50V/µs slew rate, and only 505µA supply
current. It features a rail-to-rail output stage and is
unity gain stable.
The design utilizes a patent pending topology that
provides increased slew rate performance. The common
mode input range extends to 300mV below ground
and to 1.2V below Vs. Exceeding these values will not
cause phase reversal. However, if the input voltage
exceeds the rails by more than 0.5V, the input ESD
devices will begin to conduct. The output will stay at
the rail during this overdrive condition.
The design uses a Darlington output stage. The out-
put stage is short circuit protected and offers “soft”
saturation protection that improves recovery time.
The typical circuit schematic is shown in Figure 1.
+Vs
6.8µF
+
In
0.01µF
+
Out
KM4110
-
Rf
Rg
G=2
RL = 1kΩ
Rf = 2kΩ
Rf = 1kΩ
0.1
1
10
100
Frequency (MHz)
Figure 2: Frequency Response vs. Rf
Power Dissipation
The maximum internal power dissipation allowed is
directly related to the maximum junction temperature.
If the maximum junction temperature exceeds 150°C,
some reliability degradation will occur. If the maximum
junction temperature exceeds 175°C for an extended
time, device failure may occur.
The KM4110 is short circuit protected. However, this
may not guarantee that the maximum junction tem-
perature (+150°C) is not exceeded under all condi-
tions. Follow the maximum power derating curves
shown in Figure 3 to ensure proper operation.
2.0
1.5
SOIC-8 lead
1.0
0.5 SOT23-5 lead
Figure 1: Typical Configuration
For optimum response at a gain of +2, a feedback resistor
of 1kΩ is recommended. Figure 2 illustrates the
KM4110 frequency response with both 1kΩ and 2kΩ
feedback resistors.
Enable/Disable Function (KM4120)
The KM4120 offers an active-low disable pin that can
be used to lower its supply current. Leave the pin
floating to enable the part. Pull the disable pin to the
negative supply (which is ground in a single supply
application) to disable the output. During the disable
condition, the nominal supply current will drop to
below 30µA and the output will be at high impedance
with about 2pF capacitance.
0
-50 -30 -10 10 30 50 70 90
Ambient Temperature ( C)
Figure 3: Power Derating Curves
Overdrive Recovery
For an amplifier, an overdrive condition occurs when
the output and/or input ranges are exceeded. The
recovery time varies based on whether the input or
output is overdriven and by how much the ranges are
exceeded. The KM4110 will typically recover in less
than 20ns from an overdrive condition. Figure 4
shows the KM4110 in an overdriven condition.
REV. 1A February 2001
7
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