The LM2900 series consists of four independent, dual input,
internally compensated amplifiers which were designed
specifically to operate off of a single power supply voltage
and to provide a large output voltage swing. These amplifiers make use of a current mirror to achieve the non-inverting input function. Application areas include: ac amplifiers,
RC active filters, low frequency triangle, squarewave and
pulse waveform generation circuits, tachometers and low
speed, high voltage digital logic gates.
Schematic and Connection Diagrams
Features
Y
Wide single supply voltage4 VDCto 32 V
Range or dual supplies
Y
Supply current drain independent of supply voltage
Y
Low input biasing current30 nA
Y
High open-loop gain70 dB
Y
Wide bandwidth2.5 MHz (unity gain)
Y
Large output voltage swing(V
Y
Internally frequency compensated for unity gain
Y
Output short-circuit protection
Dual-In-Line and S.O.
g
2VDCtog16 V
a
b
DC
DC
1) Vp-p
Top View
TL/H/7936– 2
Order Number LM2900N, LM3900M, LM3900N or LM3301N
TL/H/7936– 1
C
1995 National Semiconductor CorporationRRD-B30M115/Printed in U. S. A.
TL/H/7936
See NS Package Number M14A or N14A
Page 2
Absolute Maximum Ratings
If Military/Aerospace specified devices are required, please contact the National Semiconductor Sales Office/
Distributors for availability and specifications.
See AN-450 ‘‘Surface Mounting Methods and Their Effect on Product Reliability’’ for other methods of soldering surface mount
devices.
ESD tolerance (Note 7)2000V2000V
Electrical Characteristics T
e
A
25§C, V
a
ParameterConditions
OpenVoltage GainOver Temp.
Loop
Voltage Gain
Input Resistance
e
DV
10 V
O
Inverting Input
DC
Output Resistance889kX
Unity Gain BandwidthInverting Input2.52.52.5MHz
a
Input Bias CurrentInverting Input, V
Inverting Input
e
5V
DC
Slew RatePositive Output Swing0.50.50.5
Negative Output Swing202020
Supply CurrentR
OutputV
VoltageV
Swing
HighR
OUT
V
LowI
OUT
V
HighV
OUT
e %
On All Amplifiers6.2106.2106.210 mA
L
e
2k,I
L
a
e
15.0 V
DCIIN
a
e
AbsoluteI
Maximum Ratings I
b
e
IN
a
e
b
e
IN
a
e
I
IN
b
e
IN
a
e
IN
e %
R
L
OutputSource618610518
Current
Capability
Sink(Note 2)0.5 1.30.5 1.30.5 1.3mA
b
I
SINK
e
V
OL
1V, I
e
5 mA555
IN
LM2900/LM3900LM3301
DC
g
16 V
DC
20 mA
DC
b
40§Ctoa85§C
Ctoa70§C
§
b
65§Ctoa150§C
C260§C
§
C260§C
§
C215§C
§
C220§C
§
e
15 VDC, unless otherwise stated
LM2900LM3900LM3301
Min Typ Max Min Typ Max Min Typ Max
1.2 2.81.2 2.81.2 2.8
28 V
DC
g
14 V
DC
20 mA
DC
b
40§Ctoa85§C
b
65§Ctoa150§C
Units
V/mV
111MX
30 20030 20030 300
nA
V/ms
0,
13.513.513.5
0
10 mA,
0V
0.09 0.20.09 0.20.09 0.2
DC
0,
029.529.526.0
,
DC
DC
2
Page 3
a
Electrical Characteristics (Note 6), V
ParameterConditions
Power Supply Rejection T
Mirror Gain
DMirror Gain
e
25§C, fe100 Hz707070dB
A
@
20 mA (Note 3)0.901.01.10.901.01.10.9011.10
@
200 mA (Note 3)0.901.01.10.901.01.10.9011.10
@
20 mAto200mA (Note 3)252525%
e
15 VDC, unless otherwise stated (Continued)
LM2900LM3900LM3301
Min Typ MaxMin Typ Max MinTyp Max
Units
mA/mA
Mirror Current(Note 4)105001050010500mA
Negative Input CurrentT
e
25§C (Note 5)1.01.01.0mA
A
Input Bias CurrentInverting Input300300nA
Note 1: For operating at high temperatures, the device must be derated based on a 125§C maximum junction temperature and a thermal resistance of 92§C/W
which applies for the device soldered in a printed circuit board, operating in a still air ambient. Thermal resistance for the S.O. package is 131
Note 2: The output current sink capability can be increased for large signal conditions by overdriving the inverting input. This is shown in the section on Typical
Characteristics.
Note 3: This spec indicates the current gain of the current mirror which is used as the non-inverting input.
Note 4: Input V
therefore a typical design center for many of the application circuits.
Note 5: Clamp transistors are included on the IC to prevent the input voltages from swinging below ground more than approximately
currents which may result from large signal overdrive with capacitance input coupling need to be externally limited to values of approximately 1 mA. Negative input
currents in excess of 4 mA will cause the output voltage to drop to a low voltage. This maximum current applies to any one of the input terminals. If more than one
of the input terminals are simultaneously driven negative smaller maximum currents are allowed. Common-mode current biasing can be used to prevent negative
input voltages; see for example, the ‘‘Differentiator Circuit’’ in the applications section.
Note 6: These specs apply for
Note 7: Human body model, 1.5 kX in series with 100 pF.
match between the non-inverting and the inverting inputs occurs for a mirror current (non-inverting input current) of approximately 10 mA. This is
BE
40§CsT
s
a
85§C, unless otherwise stated.
A
b
C/W.
§
b
0.3 VDC. The negative input
Application Hints
When driving either input from a low-impedance source, a
limiting resistor should be placed in series with the input
lead to limit the peak input current. Currents as large as
20 mA will not damage the device, but the current mirror on
the non-inverting input will saturate and cause a loss of mirror gain at mA current levelsÐespecially at high operating
temperatures.
Precautions should be taken to insure that the power supply
for the integrated circuit never becomes reversed in polarity
or that the unit is not inadvertently installed backwards in a
test socket as an unlimited current surge through the resulting forward diode within the IC could cause fusing of the
internal conductors and result in a destroyed unit.
Output short circuits either to ground or to the positive power supply should be of short time duration. Units can be
destroyed, not as a result of the short circuit current causing
metal fusing, but rather due to the large increase in IC chip
dissipation which will cause eventual failure due to excessive junction temperatures. For example, when operating
from a well-regulated
with a 100 kX shunt-feedback resistor (from the output to
a
5VDCpower supply at T
e
25§C
A
the inverting input) a short directly to the power supply will
not cause catastrophic failure but the current magnitude will
be approximately 50 mA and the junction temperature will
be above T
current, 11 MX provides approximately 30 mA, an open cir-
max. Larger feedback resistors will reduce the
J
cuit provides 1.3 mA, and a direct connection from the output to the non-inverting input will result in catastrophic failure when the output is shorted to V
a
as this then places the
base-emitter junction of the input transistor directly across
the power supply. Short-circuits to ground will have magnitudes of approximately 30 mA and will not cause catastrophic failure at T
e
25§C.
A
Unintentional signal coupling from the output to the non-inverting input can cause oscillations. This is likely only in
breadboard hook-ups with long component leads and can
be prevented by a more careful lead dress or by locating the
non-inverting input biasing resistor close to the IC. A quick
check of this condition is to bypass the non-inverting input
to ground with a capacitor. High impedance biasing resistors used in the non-inverting input circuit make this input
lead highly susceptible to unintentional AC signal pickup.
Operation of this amplifier can be best understood by noticing that input currents are differenced at the inverting-input
terminal and this difference current then flows through the
external feedback resistor to produce the output voltage.
Common-mode current biasing is generally useful to allow
operating with signal levels near ground or even negative as
this maintains the inputs biased at
transistors (see note 5) catch-negative input voltages at approximately
b
0.3 VDCbut the magnitude of current flow has
a
VBE. Internal clamp
to be limited by the external input network. For operation at
high temperature, this limit should be approximately 100 mA.
This new ‘‘Norton’’ current-differencing amplifier can be
used in most of the applications of a standard IC op amp.
Performance as a DC amplifier using only a single supply is
not as precise as a standard IC op amp operating with split
supplies but is adequate in many less critical applications.
New functions are made possible with this amplifier which
are useful in single power supply systems. For example,
biasing can be designed separately from the AC gain as was
shown in the ‘‘inverting amplifier,’’ the ‘‘difference integrator’’ allows controlling the charging and the discharging of
the integrating capacitor with positive voltages, and the ‘‘frequency doubling tachometer’’ provides a simple circuit
which reduces the ripple voltage on a tachometer output DC
voltage.
DC
DC
3
Page 4
Typical Performance Characteristics
Open Loop GainVoltage GainVoltage Gain
Input CurrentSupply CurrentResponse
Output Sink CurrentOutput Class-A Bias CurrentOutput Source Current
Supply RejectionMirror GainMaximum Mirror Current
Large Signal Frequency
TL/H/7936– 9
4
Page 5
Typical Applications (V
Inverting Amplifier
V
ODC
j
A
V
e
b
a
e
a
V
2
R2
R1
15 VDC)
Triangle/Square Generator
TL/H/7936– 3
TL/H/7936– 4
Frequency-Doubling Tachometer
Non-Inverting Amplifier
V
e
V
ODC
R2
j
A
V
R1
TL/H/7936– 5
a
2
TL/H/7936– 7
Low V
b
V
IN
Voltage Regulator
OUT
Negative Supply Biasing
TL/H/7936– 6
R2
b
e
V
A
ODC
V
V
R3
R2
j
R1
TL/H/7936– 8
5
Page 6
Typical Applications (V
a
e
15 VDC) (Continued)
Low-Drift Ramp and Hold Circuit
Bi-Quad Active Filter
(2nd Degree State-Variable Network)
TL/H/7936– 10
Qe50
e
f
1 kHz
O
TL/H/7936– 11
6
Page 7
Typical Applications (V
a
e
15 VDC) (Continued)
Voltage-Controlled Current Source
(Transconductance Amplifier)
TL/H/7936– 12
Q1 & Q2 absorb Hi V
Hi VIN,Lo(V
IN
b
VO) Self-Regulator
IN
Ground-Referencing a Differential Input Signal
TL/H/7936– 13
TL/H/7936– 14
7
Page 8
Typical Applications (V
Voltage Regulator
Voltage-Controlled Current Sink
(Transconductance Amplifier)
a
e
15 VDC) (Continued)
e
(V
V
O
Z
TL/H/7936– 15
Fixed Current Sources
a
VBE)
R1
e
I
I
2
1
R2
TL/H/7936– 16
Buffer Amplifier
TL/H/7936– 17
Tachometer
TL/H/7936– 19
8
V
e
V
Af
ODC
*Allows VOto go to zero.
IN
t
V
IN
BE
TL/H/7936– 18
Page 9
Typical Applications (V
Low-Voltage Comparator
No negative voltage limit if
properly biased.
a
e
15 VDC) (Continued)
Power Comparator
Comparator
Square-Wave Oscillator
TL/H/7936– 20
TL/H/7936– 22
TL/H/7936– 24
Frequency Differencing Tachometer
TL/H/7936– 21
Schmitt-Trigger
TL/H/7936– 23
Pulse Generator
TL/H/7936– 25
e
A(f
b
f2)
1
V
ODC
TL/H/7936– 26
9
Page 10
Typical Applications (V
a
e
15 VDC) (Continued)
Frequency Averaging Tachometer
e
A(f
a
f2)
1
TL/H/7936– 27
V
ODC
Squaring Amplifier (W/Hysteresis)
Differentiator (Common-Mode
Biasing Keeps Input at
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with instructions for use provided in the labeling, caneffectiveness.
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