STMICROELECTRONICS ESDA25DB3RL

ESDA25DB3

Application Specific Discretes
A.S.D.
TRANSIL ARRAY
FOR ESD PROTECTION
APPLICATIONS
Where transient overvoltage protection in esd
sensitive equipment is required, such as :
- COMPUTERS
- PRINTERS
- COMMUNICATION SYSTEMS
It is particulary recommended for RS232 I/O port
protectionwhere the line interfacewithstands 2 kV,
ESD surges.
FEATURES
SO20
18 BIDIRECTIONAL TRANSIL FUNCTIONS
LOW CAPACITANCE : C = 30pF @ VRM
500 W peak pulse power (8/20 µs)
DESCRIPTION
FUNCTIONAL DIAGRAM
The ESDA25DB3 is a dual monolithic voltage
suppressor designed to protect componentswhich
are connected to data and transmission lines
against ESD.
I/O 1
1
20 I/O 18
I/O 2
2
19 I/O 17
I/O 3
3
18 I/O 16
BENEFITS
I/O 4
4
17 I/O 15
High ESD protection level : up to 25 kV
High integration
Suitable for high density boards
I/O 5
5
16 I/O 14
I/O 6
6
15 I/O 13
I/O 7
7
14 I/O 12
COMPLIESWITHTHE FOLLOWINGSTANDARDS :
I/O 8
8
13
IEC 1000-4-2 : level 4
I/O 9
9
12 I/O 10
GND 10
11
I/O 11
GND
MIL STD 883C-Method 3015-6 : class 3
(human body model)
January 1998 - Ed : 2
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ESDA25DB3
ABSOLUTE MAXIMUM RATINGS (Tamb = 25°C)
Symbol
Parameter
Value
Unit
VPP
Electrostatic discharge
MIL STD 883C - Method 3015-6
25
kV
PPP
Peak pulse power (8/20µs)
500
W
Tstg
Tj
Storage temperature range
Maximum junction temperature
- 55 to + 150
125
°C
°C
TL
Maximum lead temperature for soldering during 10s
260
°C
ELECTRICAL CHARACTERISTICS (Tamb = 25°C)
Symbol
Parameter
VRM
Stand-off voltage
VBR
Breakdown voltage
VCL
Clamping voltage
IRM
Leakage current
IPP
Peak pulse current
αT
Voltage temperature coefficient
C
Capacitance
Rd
Dynamic resistance
Types
Rd
αT
C
max.
typ.
max.
typ.
note1
note1
note 2
note 3
0V bias
V
V
mA
µA
V
Ω
-4
10 /°C
pF
25
30
1
2
24
0.5
9.7
50
VBR
min.
ESDA25DB3
@
IR
max.
note 1 : Betwenn any I/O pin Groung
note 2 : Square pulse, Ipp = 25A, tp=2.5µs.
note 3 : ∆ VBR = αT* (Tamb -25°C) * VBR (25°C)
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IRM
@
VRM
ESDA25DB3
CALCULATION OF THE CLAMPING VOLTAGE
USE OF THE DYNAMIC RESISTANCE
The ESDA family has been designed to clamp fast
spikes like ESD. Generally the PCB designers
need to calculate easily the clamping voltage VCL.
This is why we give the dynamic resistance in
addition to the classical parameters. The voltage
across the protection cell can be calculated with
the following formula:
VCL = VBR + Rd IPP
As the value of the dynamic resistance remains
stable for a surge duration lower than 20µs, the
2.5µs rectangular surge is well adapted. In addition
both rise and fall times are optimized to avoid any
parasitic phenomenon during the measurement of
Rd.
WhereIpp is the peakcurrent throughthe ESDAcell.
DYNAMIC RESISTANCE MEASUREMENT
The short duration of the ESD has led us to prefer
a more adapted test wave, as below defined, to the
classical 8/20µs and 10/1000µs surges.
I
Ipp
t
2µs
tp = 2.5µs
2.5µs duration measurement wave.
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
ESDA25DB3
Fig. 1 : Peak power dissipation versus initial
junction tempearature.
Fig. 2 : Peak pulse power versus exponential
pulse duration (Tj initial = 25 °C).
Ppp(W)
Ppp[Tj initial]/Ppp[Tj initial=25°C]
1.1
1.0
0.9
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0.0
5000
1000
tp(µs)
Tj initial(°C)
0
25
50
75
100
125
150
Fig. 3 : Clamping voltage versus peak pulse
current (Tj initial = 25 °C).
Rectangular waveform tp = 2.5 µs.
100
1
10
100
Fig. 4 : Capacitance versus reverse applied
voltage (typical values).
Ipp(A)
C(pF)
50.0
100
F=1MHz
Vosc=30mV
tp=2.5µs
10.0
50
1.0
20
VCL(V)
0.1
20
25
30
35
40
VR(V)
45
50
55
60
Fig. 5 : Relative variation of leakagecurrent versus
junction temperature (typical values).
IR[Tj] / IR[Tj=25°C]
200
100
10
Tj(°C)
1
25
50
75
100
125
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
10
1
2
5
10
30
ESDA25DB3
ORDER CODE
ESDA 25 D B 3 RL
PACKAGING:
RL = Tape and reel
= Tube
ESD ARRAY
Package: SO20
VBR min
Bidirectionel
MARKING : Logo, Date Code, E25DB3
PACKAGE MECHANICAL DATA
SO20 Plastic
DIMENSIONS
REF.
Millimetres
Min.
D
Inches
Typ. Max. Min.
Typ. Max.
hx45°
A
2.65
0.104
A
B
e
K
A1
E
A1
0.10
0.20 0.004
0.008
B
0.33
0.51 0.013
0.020
C
0.23
0.32 0.009
0.013
D
12.6
13.0 0.484
0.512
E
7.40
7.60 0.291
0.299
C
L
H
e
H
1.27
10.0
h
L
K
0.050
10.65 0.394
0.50
0.50
0.419
0.020
1.27 0.020
0.050
8° (max)
Packaging : Preferred packaging is tape and reel.
Weight : 0.55g.
Information furnished is believed to be accurate and reliable. However, SGS-THOMSON Microelectronics assumes no responsibility for the
consequences of 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 SGS-THOMSON Microelectronics. Specifications mentioned
in this publication are subject to change withoutnotice. This publication supersedes and replaces all information previously supplied.
SGS-THOMSON Microelectronics products are not authorized for use as critical components in life support devices or systems without express
written approval of SGS-THOMSON Microelectronics.
 1998 SGS-THOMSON Microelectronics - Printed in Italy - All rights reserved.
SGS-THOMSON Microelectronics GROUP OF COMPANIES
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