NSC LM9044VX, LM9044V Datasheet
TL/H/6744
LM9044 Lambda Sensor Interface Amplifier
February 1995
LM9044 Lambda Sensor Interface Amplifier
General Description
The LM9044 is a precision differential amplifier specifically
designed for operation in the automotive environment. Gain
accuracy is guaranteed over the entire automotive temperature range (
b
40§Ctoa125§C) and is factory trimmed prior
to package assembly. The input circuitry has been specifically designed to reject common-mode signals as much as
3V below ground on a single positive power supply. This
facilitates the use of sensors which are grounded at the
engine block while the LM9044 itself is grounded at chassis
potential. An external capacitor sets the maximum operating
frequency of the amplifier, thereby filtering high frequency
transients. Both inputs are protected against accidental
shorting to the battery and against load dump transients.
The input impedance is typically 1 MX.
The output op amp is capable of driving capacitive loads
and is fully protected. Also, internal circuitry has been pro-
vided to detect open circuit conditions on either or both inputs and force the output to a ‘‘home’’ position (a ratio of
the external reference voltage).
Features
Y
Normal circuit operation guaranteed with inputs up to
3V below ground on a single supply
Y
Gain factory trimmed and guaranteed over temperature
(
g
3% of full-scale fromb40§Ctoa125§C)
Y
Low power consumption (typically 1 mA)
Y
Fully protected inputs
Y
Input open circuit detection
Y
Operation guaranteed over the entire automotive temperature range (
b
40§Ctoa125§C)
Y
Single supply operation
Schematic and Connection Diagrams
TL/H/6744– 1
Plastic Chip Carrier Package
*Pins 1, 3, 4, 6, 8, 9, 10, 11, 13, 14, 16, 18, 19 are
trim pins and should be left floating.
TL/H/6744– 6
Top View
Order Number LM9044V
See NS Package Number V20A
C
1995 National Semiconductor Corporation RRD-B30M115/Printed in U. S. A.
Absolute Maximum Ratings
If Military/Aerospace specified devices are required,
please contact the National Semiconductor Sales
Office/Distributors for availability and specifications.
V
CC
Supply Voltage (RV
CC
e
15 kX)
g
60V
V
REF
Supply Voltage
b
0.3V toa6V
DC Input Voltage (Either Input)
b
3V toa16V
Input Transients (Note 1)
g
60V
Power Dissipation (see Note 6) 1350 mW
Output Short Circuit Duration Indefinite
Operating Temperature Range
b
40§Ctoa125§C
Storage Temperature Range
b
65§Ctoa150§C
Soldering Information
Plastic Chip Carrier Package
Vapor Phase (60 seconds) 215
§
C
Infrared (15 seconds) 220
§
C
See AN-450 ‘‘Surface Mounting Methods and Their Effect
on Product Reliability’’ for other methods of soldering surface mount devices.
Electrical Characteristics V
CC
e
12V, V
REF
e
5V,b40§CsT
A
s
125§C unless otherwise noted
Parameter Conditions
(Note 2) (Note 3)
Units
Min Typ Max Min Typ Max
Differential Voltage Gain V
DIF
e
0.5V 4.41 4.50 4.59 V/V
b
1VsV
CM
s
a
1V
V
DIF
e
0.5V,b3VsV
CM
s
a
1V 4.36 4.50 4.64 V/V
Gain Error (Note 5) 0sV
DIF
s
1V
b
2 0 2 %/FS
b
1VsV
CM
s
a
1V
0sV
DIF
s
1V
b
3 0 3 %/FS
b
3VsV
CM
s
a
1V
Differential Input Resistance osV
DIF
s
1V 0.95 1.20 3.00 MX
b
1VsV
CM
s
a
1V
0sV
DIF
s
1V 0.70 1.20 4.00 MX
b
3VsV
CM
s
a
1V
Non-Inverting Input Bias 0sV
DIF
s
1V
g
0.38g0.65 mA
Current
b
1VsV
CM
s
a
1V
0sV
DIF
s
1V
g
0.38g1.5 mA
b
3VsV
CM
s
a
1V
Inverting Input Bias Current 0sV
DIF
s
1V
b
25
b
65
b
100 mA
b
1VsV
CM
s
a
1V
0VsV
DIF
s
1V
b
45b150 mA
b
3VsV
CM
s
a
1V
VCCSupply Current V
CC
e
12V, RV
CC
e
15k 300 500 mA
V
REF
Supply Current 4.75VsV
REF
s
5.5V 0.5 1.0 mA
Common-Mode Voltage
b
11
b
31V
Range (Note 4)
DC Common-Mode Input Referred 50 60 dB
Rejection Ratio
b
1VsV
CM
s
a
1V
V
DIF
e
0.5V
Open Circuit Output Voltage One or Both Inputs 0.371 0.397 0.423 XV
REF
Open,b1VsV
CM
s
a
1V
b
3VsV
CM
s
a
1V 0.365 0.397 0.429 XV
REF
Short Circuit Output Current Output Grounded 1.0 2.7 5.0 mA
VCCPower Supply Rejection V
CC
e
12V, RV
CC
e
15K 50 65 dB
Ratio V
DIF
e
0.5V
V
REF
Power Supply V
REF
e
5V
DC
60 74 dB
Rejection Ratio V
DIF
e
0.5V
Note 1: This test is performed with a 1000 X source impedance.
Note 2: These parameters are guaranteed and 100% production tested.
Note 3: These parameters will be guaranteed but not 100% production tested.
Note 4: The LM9044 has been designed to common-mode to
b
3V, but production testing is only performed atg1V.
Note 5: Gain error is given as a percent of full-scale. Full-scale is defined as 1V at the input and 4.5V at the output.
Note 6: For operation in ambient temperatures above 25
§
C the device must be derated based on a maximum junction temperature of 150§C and a thermal
resistance of 93
§
C/W junction to ambient.
2
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