DB3, DB4, SMDB3
Datasheet
Diac
DO-35
2
3
SOT-23
1
Pin 1 and 3 must be shorted together
Features
• V
BO
: 32 V and 40 V
• Low breakover current
• Breakover voltage symmetry : 3V
• ECOPACK ® 2 compliant
Applications
• Triggering device for Triac or SCR based motor / light dimmer
• 32 V trigger device for oscillator circuit
• Start up triggering in lighting ballast for CFL, TL or LED lamps
Description
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 fluorescent lamp ballasts.
The surface mount SOT23-3L package allows compact, SMD based designs for automated manufacturing.
Product status link
DB3
DB4
SMDB3
DB4
Product summary
Part number
SMDB3
DB3
V
BO
28 - 36 V
28 - 36 V
35 - 45 V
DS2125 - Rev 3 - December 2018
For further information contact your local STMicroelectronics sales office.
www.st.com
1
DB3, DB4, SMDB3
Characteristics
Characteristics
Symbol
Table 1. Absolute maximum ratings (limiting values), T j
= 25 °C unless otherwise specified
Parameter
I
TRM
T stg
T j
Repetitive peak on-state current, t p
= 20 µs, F = 120 Hz
Storage junction temperature range
Operating junction temperature range
SMDB3
DB3 / DB4
Value
1.00
2.00
-40 to +125
-40 to +125
Unit
A
A
°C
°C
Table 2. Electrical characteristics (T j
= 25 °C unless otherwise specified)
Symbol Parameter Test conditions
V
BO
Breakover voltage
(1)
I V
BO1
- V
BO2
I Breakover voltage symmetry
Δ V Dynamic breakover voltage
(1)
V
O
I
BO t r
I
R
I
P
Output voltage
Breakover current
Rise time (1)
(1)
Leakage current
Peak current (1)
(1)
(1)
C = 10 nF
C = 10 nF
C = 10 nF
V
R
See
1. Applicable to both forward and reverse directions.
2. Connected in parallel to the device
(2)
(2)
V
BO
and V
F
at 10 mA
See
Figure 2. Test circuit
, (R = 20 Ω)
(2)
= 0.5 x V
BO
max
Figure 2. Test circuit
Min.
Typ.
Max.
Max.
Min.
Min.
Max.
See
Figure 3. Rise time measurement
Max.
Max.
Min.
SMDB3 DB3 DB4 Unit
28 28 35
32
36
32
36
40
45
V
3 3 3 V
10
10
10
0.5
1
1
5
5
50
2
10
5
5
50
2
10
0.30 0.30
V
V
µA
µs
µA
A
DS2125 - Rev 3 page 2/11
DS2125 - Rev 3
V
Figure 1. Voltage - current characteristic curve.
10 mA
+IF
IBO
IB
VF
0,5 VBO
Δ
V
VBO
+ V
- IF
Figure 2. Test circuit
DB3, DB4, SMDB3
Characteristics
10 k Ω 500 k Ω D.U.T
Rs = 0
220 V
50 Hz
C = 0.1 µF
Vo
R = 20 Ω
IP
T410 page 3/11
Figure 3. Rise time measurement l p
90 %
10 % t
r
DB3, DB4, SMDB3
Characteristics
DS2125 - Rev 3 page 4/11
DB3, DB4, SMDB3
Characteristics (curves)
1.1
Characteristics curves
Figure 4. Relative variation of VBO versus junction temperature (typical values)
1.05
V
BO
[T j
] / V
BO
[T j
=25 °C]
DB3 / DB4
1.00
0.95
0.90
0.85
0.80
-40 -20 0
SMDB3
20
Tj (°C)
40 60 80 100 120
Figure 5. On-state RMS current versus Triac gate current pulse duration t p
10.0
1.0
ITRM(A)
SMDB3
DB3 / DB4 f = 120 Hz
Tj initial = 25°C
0.1
1 10 tp(µs)
100
Figure 6. Triac gate current pulse duration t p
(to have I
P
> 50 mA) versus Rs and C values (typical values)
50E-6 t
P
(s)
68 Ω
40E-6
30E-6
33 Ω
47 Ω
20E-6
22 Ω
10E-6
10 Ω
00E+0
10E-9 100E-9
0 Ω
C(F)
1E-6
Note: according to Figure 2. Test circuit
DS2125 - Rev 3 page 5/11
2
2.1
DB3, DB4, SMDB3
Package information
Package information
In order to meet environmental requirements, ST offers these devices in different grades of ECOPACK ® packages, depending on their level of environmental compliance. ECOPACK ® specifications, grade definitions and product status are available at: www.st.com
. ECOPACK ® is an ST trademark.
SOT23 package information
Figure 7. SOT23-3L package outline
B
L
3
E
H
1 2
S e1 e
D c
A
A1
L
L1 a
0.25
Gauge plane
Seating plane
DS2125 - Rev 3 page 6/11
DS2125 - Rev 3
Ref.
e e1
E
H
L
S
L1 a
A
A1
B
C
D
DB3, DB4, SMDB3
SOT23-3L package information
Min.
0.89
0.00
0.30
0.085
2.75
0.85
1.70
1.20
2.10
0.35
0.25
0°
Table 3. SOT23-3L package mechanical data
Dimensions
Millimeters
Typ.
Inches (for reference only)
Typ.
Max.
1.40
0.10
0.51
0.18
3.04
1.05
2.10
1.75
3.00
Min.
0.0350
0.0000
0.0118
0.0033
0.1083
0.0335
0.0669
0.0472
0.0827
0.60
0.0236
0.65
0.55
8°
0.0138
0.0098
0°
Max.
0.0551
0.0039
0.0201
0.0071
0.1197
0.0413
0.0827
0.0689
0.1181
0.256
0.0217
8°
Figure 8. SOT23-3L footprint in mm
2.42
0.97
0.73
2.89
0.79
1.05
0.48
0.395
page 7/11
DB3, DB4, SMDB3
DO-35 package information
2.2
DO-35 package information
Figure 9. DO-35 package outline
C A C
ØD
ØB
Ref.
C
D
A
B
Min.
3.05
1.53
28.00
0.46
Millimeters
Max.
4.50
2.00
31.00
0.55
Table 4. DO-35 package mechanical data
Dimensions
Inches (for reference only)
Min.
0.120
0.060
1.102
0.018
Max.
0.177
0.079
1.220
0.022
DS2125 - Rev 3 page 8/11
3
DB3, DB4, SMDB3
Ordering information
Ordering information
Order code
SMDB3
DB3
DB4
Figure 10. Ordering information scheme
SM DB 3
Surface mount version
Diac series
Breakover voltage
3 = V
BO
typ. = 32 V
4 = V
BO
typ. = 40 V
Table 5. Ordering information
Marking
DB3
DB3 (Blue Body Coat)
DB4 (Blue Body Coat)
Package
SOT-23
DO-35
Weight
0.01 g
0.15 g
0.15 g
Base qty.
3000
5000
5000
Delivery mode
Tape and reel
Tape and reel
Tape and reel
DS2125 - Rev 3 page 9/11
Revision history
Date
18-Jun-2018
14-Dec-2018
Table 6. Document revision history
Version
2
3
Changes
First release.
Minor text change to improve readability.
DB3, DB4, SMDB3
DS2125 - Rev 3 page 10/11
DB3, DB4, SMDB3
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DS2125 - Rev 3 page 11/11
