ESDA25B1
ApplicationSpecific Discretes
A.S.D.
APPLICATIONS
Where transient overvoltage protection in ESD
sensitiveequipment is required,such as :
- COMPUTER
- PRINTERS
- COMMUNICATIONSYSTEMS
It is particulary recommended for RS232 I/O port
protectionwhere the line interface withstandsonly
2 kVESD surges.
FEATURES
6BIDIREC T IONALTRANSILFUNCTIONS
VERYLOWCAPACITANCE: C=20 pF @ V
150 W peak pulsepower (8/20 µs)
DESCRIPTION
TheESDA25B1is amonolithicvoltagesuppressor
designed to protect components which are
connected to data and transmission lines against
EDS.
RM
TRANSILARRAY
FOR ESD PROTECTION
SO-8
FUNCTIONAL DIAGRAM
BENEFITS
HighESD protectionlevel : upto 25kV
Highintegration
Suitablefor highdensity boards
COMPLIESWITH THE FOLLOWING STANDARDS :
IEC1000-4-2: level4
MILSTD 883C-Method 3015-6: class3
(humanbody model)
October 1999 - Ed : 2
I/O 1
I/O 2
I/O3 I/O4
1
2
3
4
8
7
6
5
I/O 6
I/O 5
GNDGND
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ESDA25B1
ABSOLUTEMAXIMUM RATINGS
(T
amb
=25°C)
Symbol Parameter Value Unit
V
PP
Electrostaticdischarge
25 kV
MILSTD 883C - Method3015-6
P
PP
T
stg
T
j
T
L
ELECTRICALCHARACTERISTICS
Peakpulse power (8/20µs) 150 W
Storagetemperaturerange
Maximumjunctiontemperature
Maximumlead temperatureforsoldering during 10s
=25°C)
(T
amb
- 55 to +150
125
260 °C
Symbol Parameter
V
RM
V
BR
V
CL
I
RM
Stand-offvoltage
Breakdownvoltage
Clampingvoltage
Leakagecurrent
°
°C
C
I
PP
α
T Voltagetemperaturecoefficient
Peak pulsecurrent
C Capacitance
Rd Dynamicresistance
Types V
@ I
BR
R
I
RM
@V
RM
Rd αTC
min. max. max. typ. max. typ.
note 1 note1 note 2 note3 0V bias
VVmAµAVΩ10
-4
/°CpF
ESDA25B1 25 30 1 2 24 1.5 9.7 15
note 1 : Between any I/O pin and Groung
note 2 : Square pulse, Ipp= 25A, tp=2.5µs.
note 3 : ∆ V
=αT*(Tamb -25°C)* VBR(25°C)
BR
2/5
CALCULATION OF THECLAMPING VOLTAGE
USEOF THE DYNAMICRESISTANCE
TheESDA family has been designedto clampfast
spikes like ESD. Generally the PCB designers
need to calculate easily the clampingvoltage V
CL
This is why we give the dynamic resistance in
addition to the classical parameters. The voltage
across the protection cell can be calculated with
thefollowingformula:
V
CL=VBR
+RdI
PP
WhereIppisthepeakcurrentthroughtheESDAcell.
DYNAMICRESISTANCEMEASUREMENT
Theshort durationof the ESDhas led usto prefer
amoreadapted testwave,as belowdefined,to the
classical8/20µs and 10/1000µssurges.
I
Ipp
ESDA25B1
As the value of the dynamic resistance remains
stable for a surge duration lower than 20µs, the
.
2.5µsrectangularsurgeiswelladapted. Inaddition
bothrise and falltimes are optimized to avoidany
parasiticphenomenonduring the measurementof
Rd.
2µs
tp = 2.5µs
2.5µs durationmeasurementwave.
t
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ESDA25B1
Fig. 1 :
Peak power dissipation versus initial
junctiontemperature.
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
0 25 50 75 100 125 150
Fig. 3 :
Clamping voltage versus peak pulse
Tj initial(°C)
current(Tj initial =25 °C).
Rectangularwaveformtp = 2.5 µs.
Ipp(A)
50.0
10.0
tp=2.5µs
Fig. 2 :
Peak pulse power versus exponential
pulseduration(Tj initial = 25°C).
Ppp(W)
2000
1000
100
tp(µs)
10
1 10 100
Fig. 4 : Capacitance versus reverse applied
voltage(typicalvalues).
C(pF)
20
F=1MHz
10
Vosc=30mV
1.0
0.1
20 25 30 35 40 45 50 55 60
V (V)CL
Fig.5 : Relativevariationof leakagecurrentversus
junctiontemperature(typical values).
RR
I [Tj] / I [Tj=25°C]
200
100
10
Tj(°C)
1
25 50 75 100 125
5
2
V (V)R
1
12 510 30
4/5
ORDERCODE
ESDARRAY
ESDA 25 B 1 RL
min
V
BR
Bidirectionel
ESDA25B1
PACKAGING:
RL =Tapeand reel
=Tube
PACKAGE : SO-8
MARKING :
Logo,Date Code, E25B1
PACKAGEMECHANICAL DATA
SO-8 Plastic
DIMENSIONS
REF.
Millimeters Inches
Min. Typ. Max. Min. Typ. Max.
A 1.75 0.069
a1 0.1 0.25 0.004 0.010
a2 1.65 0.065
a3 0.65 0.85 0.026 0.033
b 0.35 0.48 0.014 0.019
b1 0.19 0.25 0.007 0.010
C 0.25 0.5 0.010 0.020
c1 45°(typ)
D 4.8 5.0 0.189 0.197
E 5.8 6.2 0.228 0.244
e 1.27 0.050
e3 3.81 0.150
F 3.8 4.0 0.15 0.157
L 0.4 1.27 0.016 0.050
M 0.6 0.024
S8
°
(max)
Packaging :
Weight:
Informationfurnishedis believed to be accurate and reliable.However, STMicroelectronics assumes no responsibility for the consequences of
use of such informationnor for any infringementof patents or otherrights of third parties which may resultfrom 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 replacesall information previously supplied.
STMicroelectronics products are not authorized for use as critical components in life support devices or systems without express written approval of STMicroelectronics.
Preferredpackagingis tape and reel.
0.08g.
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