LM359 National Semiconductor, LM359 Datasheet - Page 8

• Manufacturer Part Number: LM359
• Description: Dual/ High Speed/ Programmable/ Current Mode Norton Amplifiers
• Manufacturer: National Semiconductor

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Application Hints
The following figures illustrate typical biasing schemes for
AC amplifiers using the LM359:
FIGURE 4. Biasing a Non-Inverting AC Amplifier
FIGURE 3. Biasing an Inverting AC Amplifier
FIGURE 5. nV
(Continued)
BE
Biasing
DS007788-8
DS007788-9
DS007788-10
8
The nV
applications where a reduced input impedance can be ac-
commodated (see typical applications section).
OPERATING CURRENT PROGRAMMABILITY (I
The input bias current, slew rate, gain bandwidth product,
output drive capability and total device power consumption
of both amplifiers can be simultaneously controlled and opti-
mized via the two programming pins I
I
The output set current (I
current sourced from pin 1 and establishes the class A bias-
ing current for the Darlington emitter follower output stage.
Using a single resistor from pin 1 to ground, as shown in Fig-
ure 6 , this current is equal to:
The output set current can be adjusted to optimize the
amount of current the output of the amplifier can sink to drive
load capacitance and for loads connected to V
mum output sinking current is approximately 10 times
I
device supply current if the amplifiers are not required to
drive small load impedances.
I
The input set current I
into pin 8. A resistor from pin 8 to V
I
tics of the LM359 as it directly sets the total input stage cur-
rent of the amplifiers which determines the maximum slew
rate, the frequency of the open loop dominant pole, the input
resistance of the (−) input and the biasing current I
SET(OUT)
SET(OUT)
SET(IN)
SET(IN)
FIGURE 6. Establishing the Output Set Current
FIGURE 7. Establishing the Input Set Current
BE
is most significant in controlling the AC characteris-
. This set current is best used to reduce the total
biasing configuration is most useful for low noise
SET(IN)
SET(OUT)
is equal to the current flowing
) is equal to the amount of
+
DS007788-12
DS007788-11
sets this current to be:
SET(OUT)
and I
+
. The maxi-
b
SET
(−). All of
SET(IN)
)
.