LM1819N National Semiconductor, LM1819N Datasheet - Page 2

• Manufacturer Part Number: LM1819N
• Description: IC AIR CORE MTER DVR(TACH)14DIP
• Manufacturer: National Semiconductor
• Type: Driverr

Specifications of LM1819N

• Number Of Drivers/receivers: 0/1
• Voltage - Supply: 12V
• Mounting Type: Through Hole
• Package / Case: *
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Protocol: -
• Other names: *LM1819N

Symbol
Absolute Maximum Ratings
If Military Aerospace specified devices are required
please contact the National Semiconductor Sales
Office Distributors for availability and specifications
Supply Voltage V
Power Dissipation (note 1)
Electrical Characteristics
Note 1 For operation above 25 C the LM1819 must be derated based upon a 125 C maximum junction temperature and a thermal resistance of 76 C W which
applies for the device soldered in a printed circuit board and operating in a still-air ambient
Application Hints
AIR-CORE METER MOVEMENTS
Air-core meters are often favored over other movements as
a result of their mechanical ruggedness and their indepen-
dence of calibration with age A simplified diagram of an air-
core meter is shown in Figure 2 There are three basic
pieces a magnet and pointer attached to a freely rotating
axle and two coils each oriented at a right angle with re-
spect to the other The only moving part in this meter is the
axle assembly The magnet will tend to align itself with the
vector sum of H fields of each coil where H is the magnetic
field strength vector If for instance a current passes
through the cosine coil (the reason for this nomenclature
will become apparent later) as shown in Figure 3(a) the
magnet will align its magnetic axis with the coil’s H field
Similarly a current in the sine coil ( Figure 3(b) ) causes the
magnet to align itself with the sine H field If currents are
applied simultaneously to both sine and cosine coils the
magnet will turn to the direction of the vector sum of the two
V
V
h
REG
REF
I
FE
k
S
Supply Current
Regulator Voltage
Regulator Output Resistance
Reference Voltage
Reference Output Resistance
Norton Amplifier Mirror Gain
NPN Transistor DC Gain
Function Generator Feedback
Bias Current
Drive Voltage Extremes
Sine and Cosine
Sine Output Voltage
with Zero Input
Function Generator Linearity
Function Generator Gain
a
(pin 13)
Parameter
V
S
e
Pin(s)
9 10
2 12
13 1V T
5 6
1300 mW
13
11
11
4
4
1
2
20V
A
e
Zero Input Frequency
(See Figure 1 )
I
I
I
I
I
V
I
V
FSD
Meter Deflection
REG
REG
REF
REF
BIAS
LOAD
1
8
25 C unless otherwise specified
e
e
2
Conditions
e
e
e
e
e
j 20 A
5 1V
V
e
REF
Operating Temperature
Storage Temperature
Lead Temp (Soldering 10 seconds)
BV
H fields (Figure 3(c)) H is proportional to the voltage applied
to a coil Therefore by varying both the polarity and magni-
tude of the coil voltages the axle assembly can be made to
rotate a full 360 The LM1819 is designed to drive the me-
ter through a minimum of 305
0 mA
0 A to 50 A
305
0 mA
0 mA to 3 mA
20 mA
FIGURE 2 Simplified Diagram of an Air Core Meter
CEO
V
8
b
50 75
Min
8 1
1 9
0 9
g
350
4
53 75
g
13 5
Typ
125
8 5
2 1
5 3
1 0
1 0
0
4 5
b
a
56 75
b
g
Max
65 C to
8 9
2 3
1 1
65
350
1 7
40 C to
TL H 5263 – 2
b
20V
a
%FSD
150 C
260 C
Units
85 C
mA
mA
mV
k
V
V
V
MIN
V