?2010 Littelfuse, Inc.
A U M L S e r i e s
AUML Varistor Series
RoHS
Description
The AUML Series of Multilayer Transient Surge Suppressors was speci?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 signi?cantly smaller
space and land pads than Silicon TVS diodes, offering greater circuit board layout ?exibility for the designer. Also see the Littelfuse ML, MLN and MLE Series of Multilayer Suppressors.Features
t "&$ 2 DPNQMJBOU t 3P)4 $PNQMJBOU t -PBE %VNQ FOFSHZ
rated per SAE
Speci?cation J1113 t -FBEMFTT TVSGBDF
mount chip form t i;FSPw -FBE
Inductance t 7BSJFUZ PG FOFSHZ
ratings available t /P UFNQFSBUVSF
derating up to 125oC ambient
t )JHI QFBL TVSHF
current capability t -PX 1SPmMF DPNQBDU
industry standard DIJQ TJ[F BOE 4J[FT t *OIFSFOU CJEJSFDUJPOBM
clamping t /P 1MBTUJD PS FQPYZ
packaging assures CFUUFS UIBO 7 ?ammability rating
Size T
able
Absolute Maximum Ratings
CAUTION: Stresses above those listed in “Absolute Maximum Ratings” may cause permanent damage to the device. This is a stress only rating and operation of the device at these or any other conditions above those indicated in the operational sections of this speci?cation is not implied.Applications
t 4VQQSFTTJPO PG
inductive switching or other transient events such as &'5 and surge voltage at the circuit board level t &4% QSPUFDUJPO GPS
components sensitive UP *&$ .*- 45% $ .FUIPE BOE PUIFS
industry speci?cations (See Also the MLE PS .-/ 4FSJFT
t 1SPWJEFT PO CPBSE
transient voltage protection for ICs and transistors t 6TFE UP IFMQ BDIJFWF
electromagnetic compliance of end products t 3FQMBDF MBSHFS TVSGBDF
NPVOU 574 ;FOFST JO many applications
?2010 Littelfuse, Inc.
AUML Varistor Series
Device Ratings and Speci?cations
NOTES:
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5IFSNBM TIPDL DBQBCJMJUZ QFS .JM 4UE .FUIPE $ UP $ NJOVUFT BU $ $ZDMFT NJOVUFT BU FBDI FYUSFNF 'PS BQQMJDBUJPO TQFDJmD SFRVJSFNFOUT QMFBTF DPOUBDU -JUUFMGVTF
'PS BVUPNPUJWF 7 BOE 7 BQQMJDBUJPOT QMFBTF DPOUBDU ZPVS -JUUFMGVTF SFQSFTFOUBUJWF PS WJTJU XXX MJUUFMGVTF DPN GPS UIF MBUFTU QSPEVDU
update.
Current, Energy and Power Derating Curve
8IFO USBOTJFOUT PDDVS JO SBQJE TVDDFTTJPO UIF BWFSBHF QPXFS EJTTJQBUJPO JT UIF FOFSHZ XBUU TFDPOET QFS QVMTF times the number of pulses per second. The power so developed must be within the speci?cations shown on the %FWJDF 3BUJOHT BOE $IBSBDUFSJTUJDT 5BCMF GPS UIF TQFDJmD device. Certain parameter ratings must be derated at high temperatures as shown below.
Peak Pulse Current T est Waveform for Clamping Voltage
T ypical V-I Characteristics of the V18AUMLA2220 at -40oC, 25oC, 85oC and 125oC
Maximum Leakage Current/Clamping Voltage Curve for AUML Series at 25oC
1 7JSUVBM 0SJHJO PG 8BWF
5 5JNF GSPN UP PG 1FBL T 1 3JTF 5JNF Y 5T 2 %FDBZ 5JNF
Example 'PS BO μT $VSSFOU 8BWFGPSN
8μs = T 1 3JTF 5JNF μs = T 2 %FDBZ 5JNF
?2010 Littelfuse, Inc.A U M L S e r i e s
Speed of Response
The clamping action of the AUML suppressor depends on a conduction mechanism similar to that of other TFNJDPOEVDUPS EFWJDFT J F 1 / +VODUJPOT 5IF BQQBSFOU slow response time often associated with transient WPMUBHF TVQQSFTTPST ;FOFST .07T JT PGUFO EVF UP parasitic inductance in the package and leads of the device and less dependent of the basic material (Silicon,
; N 0 5IVT UIF TJOHMF NPTU DSJUJDBM FMFNFOU BGGFDUJOH UIF
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 ns range, more than suf?cient for the transients which are likely to be encountered in an automotive environment.
T emperature Effects
In the leakage region of the AUML suppressor, the device DIBSBDUFSJTUJDT BQQSPBDIFT B MJOFBS PINJD SFMBUJPOTIJQ and shows a temperature dependent affect. In this region the suppressor is in a high resistance mode (approaching ? BOE BQQFBST BT B OFBS PQFO DJSDVJU -FBLBHF DVSSFOUT at maximum rated voltage are in the microamp range.
8IFO DMBNQJOH USBOTJFOUT BU IJHIFS DVSSFOUT BU BOE BCPWF UIF N" SBOHF UIF "6.- TVQQSFTTPS BQQSPBDIFT B DIBSBDUFSJTUJD *O UIJT SFHJPO UIF DIBSBDUFSJTUJDT of the AUML are virtually temperature independent. 'JHVSF TIPXT UIF UZQJDBM FGGFDU PG UFNQFSBUVSF PO the V-I characteristics of the AUML suppressor.
Load Dump Energy Capability
" -PBE %VNQ USBOTJFOU PDDVST XIFO UIF BMUFSOBUPS MPBE JO 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 EJGGFSFOU -PBE %VNQ TQFDJmDBUJPOT JO FYJTUFODF JO UIF automotive industry, with the most common one being that recommended by the Society of Automotive Engineers, speci?cation #SAE J1113. Because of the diversity of these -PBE %VNQ TQFDJmDBUJPOT -JUUFMGVTF EFmOFT UIF -PBE
%VNQ FOFSHZ DBQBCJMJUZ PG UIF "6.- TVQQSFTTPS SBOHF BT that energy dissipated by the device itself, independent
PG UIF UFTU DJSDVJU TFUVQ 5IF SFTVMUBOU -PBE %VNQ FOFSHZ handling capability serves as an excellent ?gure of merit for UIF "6.- TVQQSFTTPS 4UBOEBSE -PBE %VNQ TQFDJmDBUJPOT SFRVJSF B EFWJDF DBQBCJMJUZ PG QVMTFT BU SBUFE FOFSHZ BDSPTT B UFNQFSBUVSF SBOHF PG $ UP $ 5IJT capability requirement is well within the ratings of all of the "6.- 4FSJFT 'JHVSF PO OFYU QBHF
'VSUIFS UFTUJOH PO UIF "6.- 4FSJFT IBT DPODFOUSBUFE
PO FYUFOEJOH UIF OVNCFS PG -PBE %VNQ QVMTFT BU SBUFE 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 EFWJDF EVSBCJMJUZ UIF TJ[F IBT CFFO TVCKFDUFE UP PWFS QVMTFT BU JUT SBUFE FOFSHZ PG KPVMFT + UIF TJ[F IBT CFFO QVMTFE PWFS UJNFT BU + BOE TJ[F IBT CFFO QVMTFE BU JUT SBUFE FOFSHZ PG + PWFS UJNFT *O
all cases there has been little or no change in the device DIBSBDUFSJTUJDT 'JHVSF PO OFYU QBHF 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 large volume 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 EJTTJQBUF UIF -PBE %VNQ FOFSHZ
)FODF UIF QFBL UFNQFSBUVSFT HFOFSBUFE CZ UIF -PBE
%VNQ USBOTJFOU BSF TJHOJmDBOUMZ MPXFS BOE FWFOMZ EJTTJQBUFE UISPVHIPVU UIF DPNQMFUF EFWJDF 'JHVSF CFMPX 5IJT
even energy dissipation ensures that there are lower peak UFNQFSBUVSFT HFOFSBUFE BU UIF 1 / HSBJO CPVOEBSJFT PG UIF AUML suppressor.
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 tranient is of real concern, its frequency of occurrence is much less than thoe of low energy inductive spikes. Such low energy inductive spikes may be generated as a result PG NPUPST TXJUDIJOH PO BOE PGG GSPN &4% PDDVSSBODFT GVTF blowing, etc. It is essential that the suppression technology selected also has the capability to suppress such transients. 5FTUJOH PO UIF 7 "6.-" IBT TIPXO UIBU BGUFS CFJOH TVCKFDUFE UP B SFQFUJUJWF FOFSHZ QVMTF PG + PWFS UJNFT OP DIBSBDUFSJTUJD DIBOHFT IBWF PDDVSSFE 'JHVSF PO OFYU QBHF
?2010 Littelfuse, Inc.
AUML Varistor Series
AUML Load Dump Pulsing over a T emperature Range of -55oC to +125oC
Repetitive Energy T esting of V18AUMLA2220 at an Energy Level of 2 Joules
Repetitive Load Dump Pulsing at Rated Energy
Explanation of T erms
Maximum Continuous DC Working Voltage (*V . %$ +)5IJT JT UIF NBYJNVN DPOUJOVPVT %$ WPMUBHF XIJDI NBZ be applied, up to the maximum operating temperature $ UP UIF .- TVQQSFTTPS 5IJT WPMUBHF JT VTFE BT UIF reference test point for leakage current and is always less than the breakdown voltage of the device.Load Dump Energy Rating *W -%+
This is the actual energy the part is rated to dissipate
VOEFS -PBE %VNQ DPOEJUJPOT OPU UP CF DPOGVTFE XJUI UIF TPVSDF FOFSHZ PG B -PBE %VNQ UFTU TQFDJmDBUJPO Maximum Clamping Voltage *V C +
This is the peak voltage appearing across the suppressor when measured at conditions of speci?ed pulse current BOE TQFDJmFE XBWFGPSN μT *U JT JNQPSUBOU UP OPUF that the peak current and peak voltage may not necessarily be coincidental in time.Leakage Current *I L +
In the nonconducting mode, the device is at a very IJHI JNQFEBODF BQQSPBDIJOH Ω at its rated working WPMUBHF BOE BQQFBST BT BO BMNPTU PQFO DJSDVJU JO UIF system. The leakage current drawn at this level is very low (<25μ" BU BNCJFOU UFNQFSBUVSF BOE VOMJLF UIF
;FOFS EJPEF UIF NVMUJMBZFS 574 IBT UIF BEEFE BEWBOUBHF that, when operated up to its maximum temperature, JUT MFBLBHF DVSSFOU XJMM OPU JODSFBTF BCPWF μA.Nominal Voltage *V / %$ +
This is the voltage at which the AUML enters its conduction state and begins to suppress transients. In the automotive environment this voltage is EFmOFE BU UIF N" QPJOU BOE IBT B NJOJNVN
(V / %$ .*/ BOE NBYJNVN 7/ %$ ."9 WPMUBHF TQFDJmFE
?2010 Littelfuse, Inc.A U M L S e r i e s
Lead (Pb) Soldering Recommendations
The principal techniques used for the soldering of DPNQPOFOUT JO TVSGBDF NPVOU UFDIOPMPHZ BSF *3 3F nPX
BOE 8BWF TPMEFSJOH 5ZQJDBM QSPmMFT BSF TIPXO PO UIF SJHIU The termination option available for each solder technique is: 3FnPX 8BWF
/JDLFM #BSSJFS QSFGFSSFE /JDLFM #BSSJFS QSFGFSSFE 4JMWFS 1MBUJOVN
The recommended solder for the AUML suppressor is
B 4O 1
C "H 4O 1C PS 4O 1C
-JUUFMGVTF BMTP SFDPNNFOET BO 3." TPMEFS nVY
8BWF TPMEFSJOH JT UIF NPTU TUSFOVPVT PG UIF QSPDFTTFT 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.
8IFO VTJOH B SFnPX QSPDFTT DBSF TIPVME CF UBLFO UP FOTVSF UIBU UIF "6.- DIJQ JT OPU TVCKFDUFE UP B UIFSNBM gradient steeper than 4 degrees per second; the ideal HSBEJFOU CFJOH EFHSFFT QFS TFDPOE %VSJOH UIF TPMEFSJOH QSPDFTT QSFIFBUJOH UP XJUIJO EFHSFFT PG UIF TPMEFShT peak temperature is essential to minimize thermal shock. 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 UIF TPMEFS QSPDFTT BOE TVCKFDUFE UP DMFBOJOH TPMWFOUT
at room temperature. The boards must be allowed to DPPM HSBEVBMMZ UP MFTT UIBO $ CFGPSF DMFBOJOH
Lead–free (Pb-free) Soldering Recommendations Littelfuse offers the Nickel Barrier Termination ?nish for the optimum Lead–free solder performance.
5IF QSFGFSSFE TPMEFS JT 4O"H$V XJUI BO 3." ?ux, but there is a wide selection of pastes and ?uxes available with which the Nickel Barrier parts should be compatible.
The re?ow pro?le must be constrained by the maximums JO UIF -FBEoGSFF 3FnPX 1SPmMF 'PS -FBEoGSFF 8BWF TPMEFSJOH UIF 8BWF 4PMEFS 1SPmMF TUJMM BQQMJFT
Note: the Lead–free paste, ?ux and pro?le were used for evaluation purposes by Littelfuse, based upon industry standards and practices. There are multiple choices of all three available, it is advised that the customer explores the optimum combination for their process as processes vary considerably from site to site.Re?ow Solder Pro?le
Wave Solder Pro?le
Lead–free Re-?ow Solder Pro?le
?2010 Littelfuse, Inc.
AUML Varistor Series
Product Dimensions (mm)
Note: Avoid metal runs in this area, parts are not recommended
GPS VTF JO BQQMJDBUJPOT VTJOH 4JMWFS "H FQPYZ QBTUF
1"% -":065 %*.&/4*0/4
$)*1 -":065 %*.&/4*0/4
V 18AUML A 2220X X
PACKING OPTIONS
END TERMINATION OPTION DEVICE SIZE
LOAD DUMP ENERGY RATING INDICATOR
AUTOMOTIVE
MULTILAYER DESIGNATOR MAXIMUM DC
WORKING VOLTAGE DEVICE FAMIL Y A: Bulk Pack, 2500 pieces
H: 7in (178mm) Diameter Reel*T: 13in (330mm) Diameter Reel*
* See quanttities in Packaging table below No Letter: Ag/P t 2220 size only N: Nickel Barrier i.e., 220 mil x 200 mil
TVSS Device Part Numbering System
Packaging*
1BDLBHJOH *U JT SFDPNNFOEFE UIBU QBSUT CF LFQU JO UIF TFBMFE CBH QSPWJEFE BOE UIBU QBSUT CF VTFE BT TPPO BT QPTTJCMF XIFO SFNPWFE GSPN CBHT
?2010 Littelfuse, Inc.A U M L S e r i e
s t $POGPSNT UP &*" 3FWJTJPO "
t $BO CF TVQQMJFE UP *&$ QVCMJDBUJPO
/05& %JNFOTJPOT JO NJMMJNFUFST
Standard Packaging
Tape and reel is the standard packaging method of the "6.- 4FSJFT 5IF TUBOEBSE NJMMJNFUFS oJODI SFFM VUJMJ[FE DPOUBJOT QJFDFT GPS UIF BOE DIJQT QJFDFT GPS UIF DIJQ BOE QJFDFT GPS UIF TJ[F
To order: add h T h to the standard part number,
e.g.V18AUMLA222OT.
Special Packaging
Option1: NJMMJNFUFS oJODI SFFMT DPOUBJOJOH QJFDFT
BSF BWBJMBCMF 5P PSEFS BEE h)h UP UIF TUBOEBSE
QBSU OVNCFS F H 7 "6.-" )
Option 2 'PS TNBMM TBNQMF RVBOUJUJFT MFTT UIBO
QJFDFT UIF VOJUT BSF TIJQQFE CVML QBDL 5P
PSEFS BEE h"h UP UIF standard part number,
e.g.
V18AUMLA222
" T ape and Reel Speci?cations