MC34080 ONSEMI [ON Semiconductor], MC34080 Datasheet - Page 11

• Manufacturer Part Number: MC34080
• Description: HIGH PERFORMANCE JFET INPUT OPERATIONAL AMPLIFIERS
• Manufacturer: ONSEMI [ON Semiconductor]

nearly double that of currently available general purpose
JFET op–amps. This improvement in AC performance is due
to the P–channel JFET differential input stage driving a
compensated miller integration amplifier in conjunction with
an all NPN output stage.
the more conventional NPN/PNP transistor Class AB output
stage. With a 10 k load resistance, the op amp can typically
swing within 1.0 V of the positive rail (V CC ), and within 0.3 V
of the negative rail (V EE ), providing a 28.7 p–p swing from
noticeable at lower supply voltages. If the load resistance is
referenced to V CC instead of ground, the maximum possible
output swing can be achieved for a given supply voltage. For
light load currents, the load resistance will pull the output to
V CC during the positive swing and the NPN output transistor
will pull the output very near V EE during the negative swing.
The load resistance value should be much less than that of
the feedback resistance to maximize pull–up capability.
fast, contributing to the operation amplifier ’s high
gain–bandwidth product and fast settling time. The
associated high frequency output impedance is 50
at 8.0 MHz. This allows driving capacitive loads from 0 pF to
300 pF without oscillations over the military temperature
range, and over the full range of output swing. The 55 C
phase margin and 7.6 dB gain margin as well as the general
gain and phase characteristics are virtually independent of
the sink/source output swing conditions. The high frequency
characteristics of the MC34080 series is especially useful for
active filter applications.
positive rail (V CC ) to 4.0 V above the negative rail (V EE ). The
amplifier remains active if the inputs are biased at the positive
rail. This may be useful for some applications in that single
supply operation is possible with a single negative supply.
However, a degradation of offset voltage and voltage gain
may result.
noninverting input (or both) exceeds the positive common
mode limit. If either input (or both) exceeds the negative
common mode limit, the output will be in the high state. The
15 V supplies. This large output swing becomes most
MOTOROLA ANALOG IC DEVICE DATA
The bandwidth and slew rate of the MC34080 series is
The all NPN output stage offers unique advantages over
The all NPN transistor output stage is also inherently
The common mode input range is from 2.0 V below the
Phase reversal does not occur if either the inverting or
APPLICATIONS INFORMATION
MC34080 thru MC34085
(typical)
input stage also allows a differential up to 44 V, provided the
maximum input voltage range is not exceeded. The supply
voltage operating range is from 5.0 V to 22 V.
component placement and printed circuit board layout should
be exercised. For example, long unshielded input or output
leads may result in unwanted input–output coupling. In order
to reduce the input capacitance, resistors connected to the
input pins should be physically close to these pins. This not
only minimizes the input pole for optimum frequency
response, but also minimizes extraneous “pickup” at
this node.
supply pin is also important, particularly over temperature,
since many types of decoupling capacitors exhibit large
impedance changes over temperature.
offset voltage may change due to temperature cycling and
board soldering. After 20 temperature cycles (– 55 to
165 C), the typical standard deviation for input offset voltage
is 559
soldering (260 C, 10 seconds), the typical standard deviation
for input offset voltage is 525
Socketed devices should be used over a minimal
temperature range for optimum input offset voltage
performance.
For optimum frequency performance and stability, careful
Supply decoupling with adequate capacitance close to the
Primarily due to the JFET inputs of the op amp, the input
V in the plastic packages. With respect to board
Figure 34. Offset Nulling Circuit
3
2
4
V EE
+
–
V CC
7
1
5.0 k
V in the plastic package.
5
6
11