V18AUMLA2220WT [LITTELFUSE]
RESISTOR, VOLTAGE DEPENDENT, 18V, 25J, SURFACE MOUNT, CHIP, ROHS COMPLIANT;
| 型号： | V18AUMLA2220WT |
| 厂家： | 
LITTELFUSE |
| 描述： | RESISTOR, VOLTAGE DEPENDENT, 18V, 25J, SURFACE MOUNT, CHIP, ROHS COMPLIANT 电阻器 |
| 文件： | 总9页 (文件大小：425K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
Next
Previous
Surface Mount Varistors
Multilayer Transient Voltage Surge Suppressor
AUML Varistor Series
The AUML Series of Multilayer Transient Surge Suppressors was specifi-
cally designed to suppress the destructive transient voltages found in an
automobile. The most common transient condition results from large
inductive energy discharges. The electronic systems in the automobile,
e.g. antilock brake systems, direct ignition systems, engine control,
airbag control systems, wiper motor controls, etc., are susceptible to
damage from these voltage transients and thus require protection. The
AUML transient suppressors have temperature independent suppression
characteristics affording protection from -55oC to 125oC.
The AUML suppressor is manufactured from semiconducting ceramics
which offer rugged protection and excellent transient energy absorption
in a small package. The devices are available in ceramic leadless chip
form, eliminating lead inductance and assuring fast speed of response to
transient surges. These Suppressors require significantly smaller space
and land pads than silicon TVS diodes, offering greater circuit board
layout flexibility for the designer.
Also see the Littelfuse ML, MLN and MLE Series of Multilayer Suppressors.
Features
• Load Dump Energy Rated per SAE Specification J1113
• Leadless, Surface Mount Chip Form
• “Zero” Lead Inductance
• Variety of Energy Ratings Available
• No Temperature Derating up to 125oC Ambient
• High Peak Surge Current Capability
• Low Profile, Compact Industry Standard Chip Size; (1206, 1210,
1812 and 2220 Sizes)
• Inherent Bidirectional Clamping
• No Plastic or Epoxy Packaging Assures Better than 94V-0
Flammability Rating
158
www. littelfuse. com
Next
Previous
Surface Mount Varistors
Multilayer Transient Voltage Surge Suppressor
AUML Varistor Series
Absolute Maximum Ratings For ratings of individual members of a series, see Device Ratings and Specifications chart
Continuous:
AUML SERIES
UNITS
Steady State Applied Voltage:
DC Voltage Range (V
Transient:
) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
V
M(DC)
Load Dump Energy, (W ) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.5 to 25
J
V
LD
Jump Start Capability (5 minutes), (V
). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24.5
JUMP
Operating Ambient Temperature Range (T ). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -55 to 125
OC
A
Storage Temperature Range (T ) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -55 to 150
Temperature Coefficient (αv) of Clamping Voltage (V ) at Specified Test Current . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . <0.01
OC
STG
%/OC
C
3
CAUTION: Stresses above those listed in “Absolute Maximum Ratings” may cause permanent damage to the device. This is a stress only rating and operation of the device
at these or any other conditions above those indicated in the operational sections of this specification is not implied.
Device Ratings and Specifications
o
o
MAXIMUM RATINGS (125 C)
SPECIFICATIONS (25 C)
JUMP
MAXIMUM
STANDBY
LEAKAGE
(AT 13VDC)
MAXIMUM CLAMPING
MAXIMUM
CONTINUOUS
DC VOLTAGE
START
VOLTAGE
(5 MIN)
LOAD DUMP
ENERGY
(10 PULSES)
NOMINAL VARISTOR
VOLTAGE AT 10mA
DC TEST CURRENT
VOLTAGE (V )
C
AT TEST CURRENT
(8/20ms)
V
V
N(DC)
N(DC)
MIN
V
V
W
MAX
(V)
32
I
V
I
P
M(DC)
(V)
JUMP
(V)
LD
L
C
PART
NUMBER
(J)
(V)
23
23
23
23
(mA)
50
(V)
40
40
40
40
(A)
1.5
1.5
5
V18AUMLA1206
V18AUMLA1210
V18AUMLA1812
V18AUMLA2220
18
18
18
18
24.5
24.5
24.5
24.5
1.5
3
32
50
6
32
100
200
25
32
10
For automotive 24V and 42V applications please contact your Littelfuse representative or visit www.littelfuse.com for the latest product update.
NOTES:
1. Average power dissipation of transients not to exceed 0.1W, 0.15W, 0.3W and 1W for model sizes 1206, 1210, 1812 and 2220 respectively.
2. Load dump energy rating (into the suppressor) of a voltage transient with a resultant time constant of 115ms to 230ms.
o
o
o
3. Thermal shock capability per Mil-Std-750, Method 1051: -55 C to 125 C, 5 minutes at 25 C, 25 Cycles: 15 minutes at each extreme.
4. For application specific requirements, please contact Littelfuse.
100
90
Power Dissipation Ratings
80
When transients occur in rapid succession, the average power dissipa-
tion is the energy (watt-seconds) per pulse times the number of pulses
per second. The power so developed must be within the specifications
shown on the Device Ratings and Characteristics table for the specific
device. Certain parameter ratings must be derated at high temperatures
as shown in Figure 1.
70
60
50
40
30
20
10
0
-55
50 60
70
80
90 100 110 120 130 140 150
o
AMBIENT TEMPERATURE ( C)
FIGURE 1. CURRENT, ENERGY AND POWER DERATING
CURVE
159
www. littelfuse. com
Next
Previous
Surface Mount Varistors
Multilayer Transient Voltage Surge Suppressor
AUML Varistor Series
V-I Characteristics Curves
MAXIMUM LEAKAGE
100
MAXIMUM CLAMPING VOLTAGE
1210/1206
1812
2220
1210/1206
10
1812
2220
1
100mA
10mA
CURRENT
100A
10mA
100mA
1mA
1A
10A
o
FIGURE 2. MAXIMUM LEAKAGE CURRENT/CLAMPING VOLTAGE CURVE FOR AUML SERIES AT 25 C
100
o
-40 C
10
o
25 C
o
85 C
o
125 C
1
1mA
10mA
100mA
1A
10A
o
100A
o
1000A
1mA
10mA
100mA
CURRENT
o
o
FIGURE 3. TYPICAL V-I CHARACTERISTICS OF THE V18AUMLA2220 at -40 C, 25 C, 85 C AND 125 C
Temperature Effects
range), the AUML suppressor approaches a 1-10 characteristic. In
this region the characteristics of the AUML are virtually temperature
independent. Figure 3 shows the typical effect of temperature on the
V-I characteristics of the AUML suppressor.
In the leakage region of the AUML suppressor, the device characteristics
approaches a linear (ohmic) relationship and shows a temperature
dependent affect. In this region the suppressor is in a high resistance
mode (approaching 106Ω) and appears as a near open-circuit. Leakage
currents at maximum rated voltage are in the microamp range. When
clamping transients at higher currents (at and above the ten milliamp
160
www. littelfuse. com
Next
Previous
Surface Mount Varistors
Multilayer Transient Voltage Surge Suppressor
AUML Varistor Series
Hence, the peak temperatures generated by the load dump transient are sig-
nificantly lower and evenly dissipated throughout the complete device (Figure
4). This even energy dissipation ensures that there are lower peak tempera-
tures generated at the P-N grain boundaries of the AUML suppressor.
Load Dump Energy Capability
A Load dump transient occurs when the alternator load in the automobile
is abruptly reduced. The worst case scenario of this transient occurs
when the battery is disconnected while operating at full rated load. There
are a number of different load dump specifications in existence in the
automotive industry, with the most common one being that recommend-
ed by the Society of Automotive Engineers, specification #SAE J1113.
Because of the diversity of these load dump specifications Littelfuse
defines the load dump energy capability of the AUML suppressor range
as that energy dissipated by the device itself, independent of the test
circuit setup. The resultant load dump energy handling capability serves
as an excellent figure of merit for the AUML suppressor. Standard load
dump specifications require a device capability of 10 pulses at rated
energy, across a temperature range of -40oC to 125oC. This capability
requirement is well within the ratings of all of the AUML series (Figure 5).
There are a number of different size devices available in the AUML series,
each one with a load dump energy rating, which is size dependent.
Experience has shown that while the effects of a load dump transient is
of real concern, its frequency of occurrence is much less than those of
low energy inductive spikes. Such low energy inductive spikes may be
generated as a result of motors switching on and off, from ESD occur-
rences, fuse blowing, etc. It is essential that the suppression technology
selected also has the capability to suppress such transients. Testing on
the V18AUMLA2220 has shown that after being subjected to a repetitive
energy pulse of 2 joules, over 6000 times, no characteristic changes
have occurred (Figure 7.)
3
Further testing on the AUML series has concentrated on extending the
number of load dump pulses, at rated energy, which are applied to the
devices. The reliability information thus generated gives an indication of
the inherent capability of these devices. As an example of device durabil-
ity the 1210 size has been subjected to over 2000 pulses at its rated
energy of 3 joules; the 1812 size has been pulsed over 1000 times at 6
joules and 2220 size has been pulsed at its rated energy of 25 joules
over 300 times. In all cases there has been little or no change in the
device characteristics (Figure 6).
Speed of Response
The clamping action of the AUML suppressor depends on a conduction
mechanism similar to that of other semiconductor devices (i.e. P-N
Junctions). The apparent slow response time often associated with
transient voltage suppressors (Zeners, MOVs) is often due to parasitic
inductance in the package and leads of the device and less dependent
of the basic material (silicon, zinc oxide). Thus, the single most critical
element affecting the response time of any suppressor is its lead induc-
tance. The AUML suppressor is a surface mount device, with no leads or
external packaging, and thus, it has virtually zero inductance. The actual
response time of a AUML surge suppressor is in the 1 to 5 nanosecond
range, more than sufficient for the transients which are likely to be
encountered in an automotive environment.
The very high energy absorption capability of the AUML suppressor is
achieved by means of a highly controlled manufacturing process. This
technology ensures that a largevolume of suppressor material, with an
interdigitated layer construction, is available for energy absorption in an
extremely small package. Unlike equivalent rated silicon TVS diodes, the
entire AUML device volume is available to dissipate the load dump energy.
161
www. littelfuse. com
Next
Previous
Surface Mount Varistors
Multilayer Transient Voltage Surge Suppressor
AUML Varistor Series
162
www. littelfuse. com
Next
Previous
Surface Mount Varistors
Multilayer Transient Voltage Surge Suppressor
AUML Varistor Series
Soldering Recommendations
The principal techniques used for the soldering of components in surface
mount technology are Infra Red (IR) Reflow, Vapour Phase Reflow, and
Wave Soldering. When wave soldering, the suppressor is attached to the
circuit board by means of an adhesive. The assembly is then placed on a
conveyor and run through the soldering process to contact the wave.
With IR and Vapour Phase Reflow, the device is placed in a solder paste
on the substrate. As the solder paste is heated, it reflows and solders the
unit to the board.
3
The recommended solder is a 62/36/2 (Sn/Pb/Ag), 60/40 (Sn/Pb), or
63/37 (Sn/Pb). Littelfuse also recommends an RMA solder flux.
Wave soldering is the most strenuous of the processes. To avoid the
possibility of generating stresses due to thermal shock, a preheat stage
in the soldering process is recommended, and the peak temperature of
the solder process should be rigidly controlled.
When using a reflow process, care should be taken to ensure that the chip
is not subjected to a thermal gradient steeper than 4 degrees per second;
the ideal gradient being 2 degrees per second. During the soldering
process, preheating to within 100 degrees of the solders peak temperature
is essential to minimize thermal shock. Examples of the soldering condi-
tions for the AUML Series of suppressors are given in the tables below.
Once the soldering process has been completed, it is still necessary to
ensure that any further thermal shocks are avoided. One possible cause of
thermal shock is hot printed circuit boards being removed from the solder
process and subjected to cleaning solvents at room temperature. The
boards must be allowed to gradually cool to less than 50oC before cleaning.
Termination Options
Littelfuse offers two types of electrode termination finish for the Multilayer
product series:
1. Silver/Platinum (standard)
2. Silver/Palladium (optional)
163
www. littelfuse. com
Next
Previous
Surface Mount Varistors
Multilayer Transient Voltage Surge Suppressor
AUML Varistor Series
Leakage Current (I )
L
Recommended Pad Outline
In the nonconducting mode, the device is at a very high impedance
(approaching 106Ω at its rated working voltage) and appears as an almost
open circuit in the system. The leakage current drawn at this level is very
low (<25µA at ambient temperature) and, unlike the zener diode, the
multilayer TVS has the added advantage that, when operated up to its
maximum temperature, its leakage current will not increase above 500µA.
Nominal Voltage (V
)
N(DC)
This is the voltage at which the AUML enters its conduction state and
begins to suppress transients. In the automotive environment this voltage
is defined at the 10mA point and has a minimum (V
) and
N(DC) MIN
maximum (V
) voltage specified.
N(DC) MAX
Mechanical Dimensions
E
L
D
W
Explanation of Terms
Maximum Continuous DC Working Voltage (V
)
M(DC)
This is the maximum continuous DC voltage which may be applied, up to
the maximum operating temperature (125oC), to the ML suppressor. This
voltage is used as the reference test point for leakage current and is
always less than the breakdown voltage of the device.
Load Dump Energy Rating (W
)
LD
This is the actual energy the part is rated to dissipate under load dump
conditions (not to be confused with the “source energy” of a load dump
test specification).
Maximum Clamping Voltage (V )
C
This is the peak voltage appearing across the suppressor when meas-
ured at conditions of specified pulse current and specified waveform
(8/20µs). It is important to note that the peak current and peak voltage
may not necessarily be coincidental in time.
164
www. littelfuse. com
Next
Previous
Surface Mount Varistors
Multilayer Transient Voltage Surge Suppressor
AUML Varistor Series
Ordering Information
V18AUMLAXXXX TYPES
V
18 AUML A 2220
X
X
AUML SERIES
DEVICE FAMILY
TVSS Devise
PACKING OPTIONS
A: 2500 pc. Bulk Pack
3
H: 7in (178mm) Diameter Reel (Note)
T: 13in (330mm) Diameter Reel (Note)
MAXIMUM DC
WORKING VOLTAGE
END TERMINATION OPTION
AUTOMOTIVE
No Letter: Ag/P (Standard)
t
MULTILAYER DESIGNATOR
W: ag/P
d
N: Ni/Sn (up to 1210 only)
LOAD DUMP ENERGY RATING
INDICATOR
DEVICE SIZE
i.e., 220 mil x 200 mil
Note: See quantity table
Standard Shipping Quantities
Tape and Reel Specifications
• Conforms to EIA - 481, Revision A
• Can be Supplied to IEC Publication 286 - 3
165
www. littelfuse. com
Next
Previous
Surface Mount Varistors
Multilayer Transient Voltage Surge Suppressor
AUML Varistor Series
Standard Packaging
Tape and rell is the standard packaging method of the AUML series. The
standard 300 millimeter (13 inch) reel utilized contains 4000 pieces for
the 2200 and 1812 chips, 8000 pieces for the 1210 chip and 10,000
pieces for the 1206 size. To order add “T” to the standard part number,
e.g. V18AUMLA222OT.
Special Packaging
Option1: 178 millimeter (7 inch) reels containing 1000 (2220, 1812),
2000 (1210), 2500 (1206), pieces are available. To order add
“H” to the standard part number, e.g. V18AUMLA2220H.
Option 2: For small sample quantities (less than 100 pieces) the units
are shipped bulk pack. To order add “A” to the standard part
number, e.g. V18AUMLA2220A.
166
www. littelfuse. com
相关型号：
©2020 ICPDF网 联系我们和版权申明