
Low Voltage Surface Mount  
500 mW Avalanche Diodes 
SCOTTSDALE DIVISION
IN5518BUR-1 thru 1N5546BUR-1  
(or MLL5518B-1 thru MLL5546B-1) 
W
M
.
C
1
DESCRIPTION 
APPEARANCE 
The 1N5518BUR-1 thru 1N5546BUR-1 series of 0.5 watt glass surface 
mount Zener voltage regulators provides a selection from 3.3 to 33 volts in 
standard 5% tolerances as well as tighter tolerances identified by different 
suffix letters on the part number.  These have an internal-metallurgical-bond 
option as identified by the “–1” suffix.  This internally bonded Zener package 
construction is also in JAN, JANTX, and JANTXV military qualifications.  
Microsemi also offers numerous other Zener products to meet higher and 
lower power applications. 
DO-213AA
IMPORTANT:  
For the most current data, consult 
MICROSEMI’s 
 website:  
FEATURES APPLICATIONS / BENEFITS 
 
Surface mount equivalent to JEDEC registered 
1N5518 thru 1N5546 series 
 
Internal metallurgical bond with the “-1” suffix 
 
Also available in JAN, JANTX, and JANTXV 
qualifications per MIL-PRF-19500/437 by adding 
the JAN, JANTX, or JANTXV prefixes to part 
numbers for desired level of screening; (e.g. 
JANTX1N4099UR-1, JANTXV1N4109CUR-1, etc.) 
 
Nonbonded types also available without the “-1” 
suffix for both the axial and surface mount 
packages  
 
DO-7 or DO-35 glass body axial-leaded Zener 
equivalents also available per JEDEC registration 
with part numbers 1N5518 thru 1N5546 on 
separate data sheets 
MAXIMUM RATINGS 
 
Operating and Storage temperature:  -65
o
C to 
+175
C 
 
Thermal Resistance:  100
 o
C/W junction to end cap, 
or 250
C/W junction to ambient when mounted on 
FR4 PC board (1 oz Cu) with recommended 
footprint (see last page)  
 
Steady-State Power:  0.5 watts at end cap 
temperature T
EC
 < 125
C or at ambient T
A 
< 50
o
C 
when mounted on FR4 PC board as described for 
thermal resistance above (see Figure 2 for 
derating) 
 
Forward voltage @200 mA:  1.1 volts  
 
Solder Temperatures:  260
 o
C for 10 s (max)  
 
Regulates voltage over a broad operating current 
and temperature range 
Extensive selection from 3.3 to 33 V 
Standard voltage tolerances are plus/minus 5% with 
a “B” suffix, e.g. 1N5518BUR-1, etc.  
Tight tolerances available in plus or minus 2% or 1% 
with C or D suffix respectively, e.g. 1N5518CUR-1, 
1N5518DUR-1, etc. 
Hermetically sealed surface mount package 
Nonsensitive to ESD per MIL-STD-750 Method 1020 
Minimal capacitance (see Figure 3)
Inherently radiation hard as described in Microsemi 
MicroNote 050 
 
 
 
 
 
 
 
MECHANICAL AND PACKAGING
 
CASE:  Hermetically sealed glass DO-213AA 
(SOD80 or MLL34) MELF style package 
TERMINALS:  End caps tin-lead plated solderable 
per MIL-STD-750, method 2026 
POLARITY:  Cathode indicated by band where 
diode is to be operated with the banded end positive 
with respect to the opposite end for Zener regulation   
MARKING:  cathode band only  
TAPE & REEL option:  Standard per EIA-481-1-A 
with 12 mm tape, 2000 per 7 inch reel or 5000 per 
13 inch reel (add “TR” suffix to part number) 
WEIGHT:  0.04 grams 
See package dimensions on last page 
 
 
 
 
 
 
Microsemi 
Scottsdale Division 
8700 E. Thomas Rd. PO Box 1390, Scottsdale, AZ 85252 USA, (480) 941-6300, Fax: (480) 947-1503 
Page 1
Copyright 
 2003 
10-31-2003  REV B