The LM194 and LM394 are junction isolated ultra wellmatched monolithic NPN transistor pairs with an order of
magnitude improvement in matching over conventional transistor pairs. This was accomplished by advanced linear processing and a unique new device structure.
Electrical characteristics of these devices such as drift versus initial offset voltage, noise, and the exponential relationship of base-emitter voltage to collector current closely approach those of a theoretical transistor. Extrinsic emitter
and base resistances are much lower than presently available pairs, either monolithic or discrete, giving extremely low
noise and theoretical operation over a wide current range.
Most parameters are guaranteed over a current range of
1 mA to 1 mA and 0V up to 40V collector-base voltage,
ensuring superior performance in nearly all applications.
To guarantee long term stability of matching parameters,
internal clamp diodes have been added across the emitterbase junction of each transistor. These prevent degradation
due to reverse biased emitter currentÐthe most common
cause of field failures in matched devices. The parasitic isolation junction formed by the diodes also clamps the substrate region to the most negative emitter to ensure complete isolation between devices.
The LM194 and LM394 will provide a considerable improvement in performance in most applications requiring a closely
matched transistor pair. In many cases, trimming can be
eliminated entirely, improving reliability and decreasing
costs. Additionally, the low noise and high gain make this
device attractive even where matching is not critical.
The LM194 and LM394/LM394B/LM394C are available in
an isolated header 6-lead TO-5 metal can package. The
LM394/LM394B/LM394C are available in an 8-pin plastic
dual-in-line package. The LM194 is identical to the LM394
except for tighter electrical specifications and wider temperature range.
Features
Y
Y
Y
Y
Y
Y
Y
Y
LM194/LM394 Supermatch Pair
December 1994
Emitter-base voltage matched to 50 mV
Offset voltage drift less than 0.1 mV/§C
Current gain (hFE) matched to 2%
Common-mode rejection ratio greater than 120 dB
Parameters guaranteed over 1 mA to 1 mA collector
current
Extremely low noise
Superior logging characteristics compared to
conventional pairs
Plug-in replacement for presently available devices
Typical Applications
Low Cost Accurate Square Root Circuit
I
OUT
C
1995 National Semiconductor CorporationRRD-B30M115/Printed in U. S. A.
b
5
e
10
.010 V
IN
TL/H/9241– 1
*Trim for full scale accuracy
TL/H/9241
Low Cost Accurate Squaring Circuit
I
OUT
b
6
(VIN)
2
e
10
TL/H/9241– 2
Page 2
Absolute Maximum Ratings
If Military/Aerospace specified devices are required,
please contact the National Semiconductor Sales
Office/Distributors for availability and specifications.
(Note 4)
Collector Current20 mA
Collector-Emitter VoltageV
Collector-Emitter Voltage35V
LM394C20V
Collector-Base Voltage35V
LM394C20V
Collector-Substrate Voltage35V
LM394C20V
Collector-Collector Voltage35V
LM394C20V
MAX
Base-Emitter Current
g
10 mA
Power Dissipation500 mW
Junction Temperature
LM194
LM394/LM394B/LM394C
Storage Temperature Range
b
55§Ctoa125§C
b
25§Ctoa85§C
b
65§Ctoa150§C
Soldering Information
Metal Can Package (10 sec.)260
Dual-In-Line Package (10 sec.)260
Small Outline Package
Vapor Phase (60 sec.)215
Infrared (15 sec.)220
See AN-450 ‘‘Surface Mounting and their Effects on Product Reliability’’ for other methods of soldering surface
mount devices.
C
§
C
§
C
§
C
§
Electrical Characteristics (T
ParameterConditions
e
25§C)
J
LM194LM394LM394B/394C
Units
Min Typ Max Min Typ Max Min Typ Max
Current Gain (hFE)V
Current Gain Match,V
(hFEMatch)I
][
e
100[DI
h
B
FE(MIN)
I
C
Emitter-Base OffsetV
VoltageI
e
0V to V
CB
e
I
1 mA350700300 700225500
C
e
I
100 mA350 550250550200 400
C
e
I
10 mA300 450200450150 300
C
e
I
1 mA200 300150300100 200
C
e
0V to V
CB
e
10 mA to 1 mA0.520.541.05%
C
]
e
I
1 mA1.01.02.0%
C
e
0
CB
e
1 mAto1mA
C
MAX
MAX
(Note 1)
251002515050200mV
Change in Emitter-Base(Note 1)
Offset Voltage vsI
Collector-Base VoltageV
(CMRR)
Change in Emitter-BaseV
Offset Voltage vsI
Collector Current
Emitter-Base OffsetI
Voltage TemperatureI
DriftVOSTrimmed to 0 at 25§C0.030.10.030.30.030.5mV/§C
Logging ConformityI
Collector-Base Leakage V
Collector-CollectorV
Leakage
Input Voltage NoiseI
Collector to EmitterI
Saturation VoltageI
Note 1: Collector-base voltage is swept from 0 to V
Note 2: Offset voltage drift with V
within 0.003% over the entire temperature range. Measurements taken at
Note 3: Logging conformity is measured by computing the best fit to a true exponential and expressing the error as a base-emitter voltage deviation.
Note 4: Refer to RETS194X drawing of military LM194H version for specifications.
e
1 mAto1mA,
C
e
0V to V
CB
e
CB
e
C
e
C
e
C1
e
C
e
V
CB
e
CB
e
CC
e
C
e
100 Hz to 100 kHz
f
e
C
e
C
e
OS
MAX
0V,
1 mA to 0.3 mA
10 mA to 1 mA (Note 2)
I
C2
3nAto300mA,
0, (Note 3)
V
MAX
V
MAX
100 mA, V
e
1 mA, I
B
e
1 mA, I
B
e
0atT
25§C is valid only when the ratio of IC1to IC2is adjusted to give the initial zero offset. This ratio must be held to
A
1025105010100mV
525550550 mV
0.080.30.081.00.21.5mV/
150150150mV
0.05 0.250.050.50.050.5nA
0.12.00.15.00.15.0nA
e
0V,
CB
1.81.81.8nV/
10 mA0.20.20.2V
100 mA0.10.10.1V
at a collector current of 1 mA, 10 mA, 100 mA, and 1 mA.
MAX
a
25§C and temperature extremes.
0
§
Hz
C
2
Page 3
Typical Applications (Continued)
Fast, Accurate Logging Amplifier, V
e
10V to 0.1 mV or I
IN
e
1mAto10nA
IN
Voltage Controlled Variable Gain Amplifier
*1kX(g1%) at 25§C,a3500 ppm/§C.
Available from Vishay Ultronix,
Grand Junction, CO, Q81 Series.
eb
V
OUT
TL/H/9241– 3
V
IN
log
10
V
#
J
REF
*R8– R10 and D2 provide a temperature Distortionk0.1%
independent gain control.Bandwidth
eb
336 V1 (dB)100 dB gain range
G
l
1 MHz
3
TL/H/9241– 4
Page 4
Typical Applications (Continued)
Precision Low Drift Operational Amplifier
Common-mode range 10V
I
25 nA
BIAS
I
0.5 nA
OS
V
(untrimmed) 125 mV
OS
(DV
/DT) 0.2 mV/C
OS
CMRR 120 dB
A
2,500,000
VOL
*C 200 pF for unity gain
C 30 pF for A
C 5 pF for A
C 0 pF for AV1000
10
V
100
V
TL/H/9241– 5
High Accuracy One Quadrant Multiplier/Divider
(X) (Y)
e
V
OUT
*Typical linearity 0.1%
; positive inputs only.
(Z)
4
TL/H/9241– 6
Page 5
Typical Applications (Continued)
High Performance Instrumentation Amplifier
6
10
e
*Gain
R
S
Performance Characteristics
Ge10,000 Ge1,000 Ge100 Ge10
g
Linearity of Gain (
10V Output)
Common-Mode Rejection Ratio (60 Hz)
Common-Mode Rejection Ratio (1 kHz)
Power Supply Rejection Ratio
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DEVICES OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF THE PRESIDENT OF NATIONAL
SEMICONDUCTOR CORPORATION. As used herein:
1. Life support devices or systems are devices or2. A critical component is any component of a life
systems which, (a) are intended for surgical implantsupport device or system whose failure to perform can
into the body, or (b) support or sustain life, and whosebe reasonably expected to cause the failure of the life
failure to perform, when properly used in accordancesupport device or system, or to affect its safety or
with instructions for use provided in the labeling, caneffectiveness.
be reasonably expected to result in a significant injury
to the user.
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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.