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DB3 DB4 SMDB3
October 2001 - Ed: 2B
DIAC
DO-35
(DB3 and DB4)
s
V
BO
: 32V and 40V
s
LOW BREAKOVER CURRENT
FEATURES
Functioning as a trigger diode with a fixed voltage
reference, the DB3/DB4 series can be used in
conjunction with triacs for simplified gate control
circuits or as a starting element in fluorenscent
lamp ballasts.
A new surface mount version is now available in
SOT-23 package, providing reduced space and
compatibility with automatic pick and place
equipment.
DESCRIPTION
Symbol
Parameter
Value
Unit
I
TRM
Repetitive peak on-state current
tp = 20
s
F= 120 Hz
SMDB3
1.00
A
DB3 / DB4
2.00
Tstg
Tj
Storage temperature range
Operating junction temperature range
- 40 to + 125
C
ABSOLUTE MAXIMUM RATINGS (limiting values)
1
2
3
SOT-23
(SMDB3)*
Pin 1 and 3 must be shorted
together
Note: * SMDB3 indicated as Preliminary spec as product is still in development stage.
DB3 DB4 SMDB3
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Symbol
Parameter
Test Conditions
SMDB3
DB3
DB4
Unit
V
BO
Breakover voltage *
C = 22nF **
MIN.
28
28
35
V
TYP.
32
32
40
MAX.
36
36
45
I V
BO1
- V
BO2
I
Breakover voltage
symmetry
C = 22nF **
MAX.
3
V
V
Dynamic breakover
voltage *
V
BO
and V
F
at 10mA
MIN.
10
5
V
V
O
Output voltage *
see diagram 2
(R=20
)
MIN.
10
5
V
I
BO
Breakover current *
C = 22nF **
MAX.
10
50
A
tr
Rise time *
see diagram 3
MAX.
0.50
2
s
I
R
Leakage current *
V
R
= 0.5 V
BO
max
MAX.
1
10
A
I
P
Peak current *
see diagram 2 (Gate)
MIN.
1
0.30
A
* Applicable to both forward and reverse directions.
** Connected in parallel to the device.
ELECTRICAL CHARACTERISTICS (Tj = 25C unless otherwise specified)
Part Number
V
BO
Package
SMDB3
28 - 36
SOT-23
DB3
28 - 36
DO-35
DB4
35 - 45
DO-35
PRODUCT SELECTOR
SM DB 3
Surface
Mount
Version
Diac Series
Breakover voltage
3: V
typ = 32V
4: V
typ = 40V
BO
BO
ORDERING INFORMATION
DB3 DB4 SMDB3
3/5
10mA
IBO
IB
- V
+ V
+ IF
- IF
0,5 VBO
VBO
V
VF
Diagram 1: Voltage - current characteristic curve.
D.U.T
Vo
C=0.1F
220 V
50 Hz
500 k
10 k
R=20
I
P
Rs=0
T410
Diagram 2: Test circuit.
90 %
l
p
10 %
tr
Diagram 3: Rise time measurement.
Part Number
Marking
Weight
Base Quantity
Packing Mode
SMDB3
DB3
0.01 g
3000
Tape & Reel
DB3
DB3 (Blue Body Coat)
0.15 g
5000
Tape & Reel
DB4
DB4 (Blue Body Coat)
0.15 g
5000
Tape & Reel
OTHER INFORMATION
DB3 DB4 SMDB3
4/5
10
20
50
100
200
500
0
5
10
15
20
25
30
35
40
C(nF)
tp(s)
Tj=25C
0
10
22
68
47
33
Fig. 3: Time duration while current pulse is higher
50mA versus C and Rs (typical values).
PACKAGE MECHANICAL DATA (in millimeters)
DO-35
REF.
DIMENSIONS
Millimeters
Inches
Min.
Max.
Min.
Max.
A
3.05
4.50
0.120
0.177
B
1.53
2.00
0.060
0.079
C
28.00
1.102
D
0.458
0.558
0.018
0.022
C
A
B
O
/
O
/
D
O
/
D
C
25
50
75
100
125
0.80
0.85
0.90
0.95
1.00
1.05
1.10
Tj(C)
VBO [Tj] / VBO [Tj=25C]
SMDB3
DB3/DB4
Fig. 1: Relative variation of VBO versus junction
temperature (typical values).
1
10
100
0.1
1.0
10.0
20.0
tp(s)
ITRM(A)
SMDB3
DB3/DB4
F=120Hz
Tj initial=25C
Fig. 2: Repetitive peak pulse current versus pulse
duration (maximum values).
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DB3 DB4 SMDB3
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use of such information nor for any infringement of patents or other rights of third parties which may result from its use. No license is granted by
implication or otherwise under any patent or patent rights of STMicroelectronics. Specifications mentioned in this publication are subject to
change without notice. This publication supersedes and replaces all information previously supplied.
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proval of STMicroelectronics.
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PACKAGE MECHANICAL DATA (in millimeters)
SOT-23
B
E
S
e
e1
A
D
c
L
H
A1
REF.
DIMENSIONS
Millimeters
Inches
Min.
Max.
Min.
Max.
A
0.89
1.4
0.035
0.055
A1
0
0.1
0
0.004
B
0.3
0.51
0.012
0.02
c
0.085
0.18
0.003
0.007
D
2.75
3.04
0.108
0.12
e
0.85
1.05
0.033
0.041
e1
1.7
2.1
0.067
0.083
E
1.2
1.6
0.047
0.063
H
2.1
2.75
0.083
0.108
L
0.6 typ.
0.024 typ.
S
0.35
0.65
0.014
0.026
0.9
0.035
0.9
0.035
1.9
0.075
mm
inch
2.35
0.92
1.1
0.043
1.1
0.043
1.45
0.037
0.9
0.035
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