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LM146/LM346
Programmable Quad Operational Amplifiers
General Description
The LM146 series of quad op amps consists of four independent, high gain, internally compensated, low power, programmable amplifiers. Two external resistors (R
SET
) allow
the user to program the gain bandwidth product, slew rate,
supply current, input bias current, input offset current and input noise. For example, the user can trade-off supply current
for bandwidth or optimize noise figure for a given source resistance. In a similar way, other amplifier characteristics can
be tailored to the application. Except for the two programming pins at the end of the package, the LM146 pin-out is
the same as the LM124 and LM148.
Features
(I
SET
=
10 µA)
n Programmable electrical characteristics
n Battery-powered operation
n Low supply current: 350 µA/amplifier
n Guaranteed gain bandwidth product: 0.8 MHz min
n Large DC voltage gain: 120 dB
n Low noise voltage: 28
n Wide power supply range:±1.5V to±22V
n Class AB output stage–no crossover distortion
n Ideal pin out for Biquad active filters
n Input bias currents are temperature compensated
Connection Diagram
PROGRAMMING EQUATIONS
Total Supply Current=1.4 mA (I
SET
/10 µA)
Gain Bandwidth Product=1 MHz (I
SET
/10 µA)
Slew Rate=0.4V/µs (I
SET
/10 µA)
Input Bias Current
≅
50 nA (I
SET
/10 µA)
I
SET
=
Current into pin 8, pin 9 (see schematic-diagram)
Dual-In-Line Package
DS005654-1
Top View
Order Number LM146J, LM146J/883,
LM346M or LM346N
See NS Package Number
J16A, M16A or N16A
May 1999
LM146/LM346 Programmable Quad Operational Amplifiers
© 1999 National Semiconductor Corporation DS005654 www.national.com
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Schematic Diagram
DS005654-2
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Page 3
Absolute Maximum Ratings (Notes 1, 5)
If Military/Aerospace specified devices are required, please contact the National Semiconductor Sales Office/
Distributors for availability and specifications.
LM146 LM346
Supply Voltage
±
22V
±
18V
Differential Input Voltage (Note 1)
±
30V
±
30V
CM Input Voltage (Note 1)
±
15V
±
15V
Power Dissipation (Note 2) 900 mW 500 mW
Output Short-Circuit Duration (Note 3) Continuous Continuous
Operating Temperature Range −55˚C to +125˚C 0˚C to +70˚C
Maximum Junction Temperature 150˚C 100˚C
Storage Temperature Range −65˚C to +150˚C −65˚C to +150˚C
Lead Temperature (Soldering, 10 seconds) 260˚C 260˚C
Thermal Resistance (θ
jA
), (Note 2)
Cavity DIP (J) Pd 900 mW 900 mW
θ
jA
100˚C/W 100˚C/W
Small Outline (M) θ
jA
115˚C/W
Molded DIP (N) Pd 500 mW
θ
jA
90˚C/W
Soldering Information
Dual-In-Line Package
Soldering (10 seconds) +260˚C +260˚C
Small Outline Package
Vapor Phase (60 seconds) +215˚C +215˚C
Infrared (15 seconds) +220˚C +220˚C
SeeAN-450 “Surface Mounting Methods and Their Effect on Product Reliability” for other methods of soldering surface mount devices.
ESD rating is to be determined.
DC Electrical Characteristics
(V
S
=
±
15V, I
SET
=
10 µA), (Note 4)
Parameter Conditions LM146 LM346 Units
Min Typ Max Min Typ Max
Input Offset Voltage V
CM
=
0V, R
S
≤50Ω,T
A
=
25˚C 0.5 5 0.5 6 mV
Input Offset Current V
CM
=
0V, T
A
=
25˚C 2 20 2 100 nA
Input Bias Current V
CM
=
0V, T
A
=
25˚C 50 100 50 250 nA
Supply Current (4 Op Amps) T
A
=
25˚C 1.4 2.0 1.4 2.5 mA
Large Signal Voltage Gain R
L
=
10 kΩ, ∆V
OUT
=
±
10V, 100 1000 50 1000 V/mV
T
A
=
25˚C
Input CM Range T
A
=
25˚C
±
13.5±14
±
13.5±14 V
CM Rejection Ratio R
S
≤10 kΩ,T
A
=
25˚C 80 100 70 100 dB
Power Supply Rejection Ratio R
S
≤10 kΩ,T
A
=
25˚C, 80 100 74 100 dB
V
S
=
±
5to±15V
Output Voltage Swing R
L
≥10 kΩ,T
A
=
25˚C
±
12
±
14
±
12
±
14 V
Short-Circuit T
A
=
25˚C 5 20 35 5 20 35 mA
Gain Bandwidth Product T
A
=
25˚C 0.8 1.2 0.5 1.2 MHz
Phase Margin T
A
=
25˚C 60 60 Deg
Slew Rate T
A
=
25˚C 0.4 0.4 V/µs
Input Noise Voltage f=1 kHz, T
A
=
25˚C 28 28
Channel Separation R
L
=
10 kΩ, ∆V
OUT
=
0V to 120 120 dB
±
12V, T
A
=
25˚C
Input Resistance T
A
=
25˚C 1.0 1.0 MΩ
Input Capacitance T
A
=
25˚C 2.0 2.0 pF
Input Offset Voltage V
CM
=
0V, R
S
≤50Ω 0.5 6 0.5 7.5 mV
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DC Electrical Characteristics (Continued)
(V
S
=
±
15V, I
SET
=
10 µA), (Note 4)
Parameter Conditions LM146 LM346 Units
Min Typ Max Min Typ Max
Input Offset Current V
CM
=
0V 2 25 2 100 nA
Input Bias Current V
CM
=
0V 50 100 50 250 nA
Supply Current (4 Op Amps) 1.7 2.2 1.7 2.5 mA
Large Signal Voltage Gain R
L
=
10 kΩ, ∆V
OUT
=
±
10V 50 1000 25 1000 V/mV
Input CM Range
±
13.5±14
±
13.5±14 V
CM Rejection Ratio R
S
≤50Ω 70 100 70 100 dB
Power Supply Rejection Ratio R
S
≤50Ω, 76 100 74 100 dB
V
S
=
±
5V to±15V
Output Voltage Swing R
L
≥10 kΩ
±
12
±
14
±
12
±
14 V
DC Electrical Characteristic
(V
S
=
±
15V, I
SET
=
10 µA)
Parameter Conditions LM146 LM346 Units
Min Typ Max Min Typ Max
Input Offset Voltage V
CM
=
0V, R
S
≤50Ω, 0.5 5 0.5 7 mV
T
A
=
25˚C
Input Bias Current V
CM
=
0V, T
A
=
25˚C 7.5 20 7.5 100 nA
Supply Current (4 Op Amps) T
A
=
25˚C 140 250 140 300 µA
Gain Bandwidth Product T
A
=
25˚C 80 100 50 100 kHz
DC Electrical Characteristics
(V
S
=
±
1.5V, I
SET
=
10 µA)
Parameter Conditions LM146 LM346 Units
Min Typ Max Min Typ Max
Input Offset Voltage V
CM
=
0V, R
S
≤50Ω, 0.5 5 0.5 7 mV
T
A
=
25˚C
Input CM Range T
A
=
25˚C
±
0.7
±
0.7 V
CM Rejection Ratio R
S
≤50Ω,T
A
=
25˚C 80 80 dB
Output Voltage Swing R
L
≥10 kΩ,T
A
=
25˚C
±
0.6
±
0.6 V
Note 1: For supply voltages less than±15V, the absolute maximum input voltage is equal to the supply voltage.
Note 2: The maximum power dissipation for these devices must be derated at elevated temperatures and is dictated by T
jMAX
, θjA, and the ambient temperature,
T
A
. The maximum available power dissipation at any temperature is P
d
=
(T
jMAX-TA
)/θjAor the 25˚C P
dMAX
, whichever is less.
Note 3: Any of the amplifier outputs can be shorted to ground indefinitely; however, more than one should not be simultaneously shorted as the maximum junction
temperature will be exceeded.
Note 4: These specifications apply over the absolute maximum operating temperature range unless otherwise noted.
Note 5: Refer to RETS146X for LM146J military specifications.
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Typical Performance Characteristics
Input Bias Current vs I
SET
DS005654-44
Supply Current vs I
SET
DS005654-45
Open Loop Voltage Gain
vs I
SET
DS005654-46
Slew Rate vs I
SET
DS005654-47
Gain Bandwidth Product
vs I
SET
DS005654-48
Phase Margin vs I
SET
DS005654-49
Input Offset Voltage
vs I
SET
DS005654-50
Common-Mode Rejection
Ratio vs I
SET
DS005654-51
Power Supply Rejection
Ratio vs I
SET
DS005654-52
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Typical Performance Characteristics (Continued)
Open Voltage Swing vs
Supply Voltage
DS005654-53
Input Voltage Range vs
Supply Voltage
DS005654-54
Input Bias Current vs
Input Common-Mode
Voltage
DS005654-55
Input Bias Current vs
Temperature
DS005654-56
Input Offset Current vs
Temperature
DS005654-57
Supply Current vs
Temperature
DS005654-58
Open Loop Voltage Gain
vs Temperature
DS005654-20
Gain Bandwidth Product
vs Temperature
DS005654-21
Slew Rate vs
Temperature
DS005654-22
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Typical Performance Characteristics (Continued)
Application Hints
Avoid reversing the power supply polarity; the device will fail.
Common-Mode Input Voltage: The negative
common-mode voltage limit is one diode drop above the
negative supply voltage. Exceeding this limit on either input
will result in an output phase reversal. The positive
common-mode limit is typically 1V below the positive supply
voltage. No output phase reversal will occur if this limit is exceeded by either input.
Output VoltageSwing vs I
SET
: For a desired output voltage
swing the value ofthe minimum load depends on the positive
and negative output current capability of the op amp. The
maximum available positive output current, (I
CL+
), of the de-
vice increases with I
SET
whereas the negative output current
(I
CL−
) is independent of I
SET
.
Figure 1
illustrates the above.
Input Noise Voltage vs
Frequency
DS005654-23
Input Noise Current vs
Frequency
DS005654-24
Power Supply Rejection
Ratio vs Frequency
DS005654-25
Voltage Follower Pulse
Response
DS005654-26
Voltage Follower Transient
Response
DS005654-27
Transient Response Test Circuit
DS005654-6
DS005654-7
FIGURE 1. Output Current Limit vs I
SET
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Application Hints (Continued)
Input Capacitance: The input capacitance, C
IN
,ofthe
LM146 is approximately 2 pF; any stray capacitance, C
S
,
(due to external circuit circuit layout) will add to C
IN
. When
resistive or active feedback is applied, an additional pole is
added to the open loop frequency response of the device.
For instance with resistive feedback (
Figure 2
), this pole oc-
curs at
1
⁄2π (R1||R2) (CIN+CS). Make sure that this pole occurs at least 2 octaves beyond the expected −3 dB frequency corner of the closed loop gain of the amplifier; if not,
place a lead capacitor in the feedback such that the time
constant of this capacitor and the resistance it parallels is
equal to the R
I(CS+CIN
), where RIis the input resistance of
the circuit.
Temperature Effect on the GBW: The GBW (gain bandwidth product), of the LM146 is directly proportional to I
SET
and inversely proportional to the absolute temperature.
When using resistors to set the bias current, I
SET
, of the device, the GBW product will decrease with increasing temperature. Compensation can be provided by creating an I
SET
current directly proportional to temperature (see typical applications).
Isolation Between Amplifiers: The LM146 die is isothermally layed out such that crosstalk between
all 4
amplifiers is
in excess of −105 dB (DC). Optimum isolation (better than
−110 dB) occurs between amplifiers A and D, B and C; that
is, if amplifier A dissipates power on its output stage, amplifier D is the one which will be affected the least, and vice
versa. Same argument holds for amplifiers B and C.
LM146 TypicalPerformance Summary: The LM146 typical
behaviour is shown in
Figure 3
. The device is fully predict-
able. As the set current, I
SET
, increases, the speed, the bias
current, and the supply current increase while the noise
power decreases proportionally and the V
OS
remains con-
stant. The usable GBW range of the op amp is 10 kHz to
3.5−4 MHz.
Low Power Supply Operation: The quad op amp operates
down to
±
1.3V supply. Also, since the internal circuitry is biased through programmable current sources, no degradation of the device speed will occur.
Speed vs Power Consumption: LM146 vs LM4250 (single
programmable). Through
Figure 4
, we observe that the
LM146’s power consumption has been optimized for GBW
products above 200 kHz, whereas the LM4250 will reach a
GBW of no more than 300 kHz. For GBW products below
200 kHz, the LM4250 will consume less power.
DS005654-9
FIGURE 2.
DS005654-8
FIGURE 3. LM146 Typical Characteristics
DS005654-10
FIGURE 4. LM146 vs LM4250
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Typical Applications
Dual Supply or Negative Supply Blasing
DS005654-39
Single (Positive) Supply Blasing
DS005654-11
Current Source Blasing
with Temperature Compensation
DS005654-40
•
The LM334 provides an I
SET
directly proportional to absolute
temperature. This cancels the slight GBW product Temperature coefficient
of the LM346.
Blasing all 4 Amplifiers
with Single Current Source
DS005654-41
•
For I
SET1
≅
I
SET2
resistors R1 and R2 are not required if a slight error
between the 2 set currents can be tolerated.
If not, then use R1=R2 to create a 100 mV drop across these resistors.
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Active Filters Applications
Basic (Non-Inverting “State Variable”) Active Filter Building Block
DS005654-12
DS005654-33
Note. All resistor values are given in ohms.
DS005654-13
DS005654-34
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Active Filters Applications (Continued)
Circuit Synthesis Equations
DS005654-35
A Simple-to-Design BP, LP Filter Building Block
DS005654-14
•
If resistive biasing is used to set the LM346 performance, the Qoof this filter building block is nearly insensitive to the op amp’s GBW product temperature
drift; it has also better noise performance than the state variable filter.
DS005654-36
•
For the eventual use of amplifier C, see comments on the previous page.
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Active Filters Applications (Continued)
Circuit Synthesis Equations
A 3-Amplifier Notch Filter (or Elliptic Filter Building Block)
DS005654-15
DS005654-37
•
For nothing but a notch output: R
IN
=
R, C'=C.
Capacitorless Active Filters (Basic Circuit)
DS005654-16
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Active Filters Applications (Continued)
Miscellaneous Applications
DS005654-38
1. Pick up a convenient value for b; (b<1)
2. Adjust Q
o
through R5
3. Adjust H
o(BP)
through R4
4. Adjust f
o
through R
SET
. This adjusts the unity gain frequency (fu) of the op amp.
A 4th Order Butterworth Low Pass Capacitorless Filter
DS005654-17
Ex: f
c
=
20 kHz, H
o
(gain of the filter)=1, Q
01
=
0.541, Q
o2
=
1.306.
•
Since for this filter the GBW product of all 4 amplifiers has been designed to be the same (z1 MHz) only one current source can be used to bias the circuit.
Fine tuning can be further accomplished through Rb.
A Unity Gain Follower
with Bias Current Reduction
DS005654-18
•
For better performance, use a matched NPN pair.
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Miscellaneous Applications (Continued)
Circuit Shutdown
DS005654-42
•
By pulling the SET pin(s) to V−the op amp(s) shuts down and its output goes to a high impedance state. According to this property, the LM346 can be used
as a very low speed analog switch.
Voice Activated Switch and Amplifier
DS005654-43
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Miscellaneous Applications (Continued)
X10 Micropower Instrumentation Amplifier with Buffered Input Guarding
DS005654-19
•
CMRR: 100 dB (typ)
•
Power dissipation: 0.4 mW
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Physical Dimensions inches (millimeters) unless otherwise noted
Cavity Dual-In-Line Package (J)
Order Number LM146J, LM146J/883
NS Package Number J16A
S.O. Package (M)
Order Number LM346M
NS Package Number M16A
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Physical Dimensions inches (millimeters) unless otherwise noted (Continued)
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COUNSEL OF NATIONAL SEMICONDUCTOR CORPORATION. As used herein:
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into the body, or (b) support or sustain life, and
whose failure to perform when properly used in
accordance with instructions for use provided in the
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significant injury to the user.
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support device or system whose failure to perform
can be reasonably expected to cause the failure of
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Molded Dual-In-Line Package (N)
Order Number LM346N
NS Package Number N16A
LM146/LM346 Programmable Quad Operational Amplifiers
National does not assume any responsibility for use of any circuitry described, no circuit patent licenses are implied and National reserves the right at any time without notice to change said circuitry and specifications.
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