SRDA3.3-4
STEERING DIODE/ TVS ARRAY COMBO
105208.R3 12/07 www.protekdevices.com
APPLICATIONS
✔ Ethernet - 10/100 Base T
✔ Computer I/O Ports - SCSI, FireWire & USB
✔ Set-Top Box Protection
✔ Video Card
IEC COMPATIBILITY (EN61000-4)
✔ 61000-4-2 (ESD): Air - 15kV, Contact - 8kV
✔ 61000-4-4 (EFT): 40A - 5/50ns
✔ 61000-4-5 (Surge): 24A, 8/20µs - Level 2(Line-Gnd) & Level 3(Line-Line)
FEATURES
✔ 500 Watts Peak Pulse Power per Line (tp=8/20µs)
✔ Unidirectional Configuration
✔ Available in 3.3V
✔ Protects Up to Four (4) I/O Ports
✔ ESD Protection > 40 kilovolts
✔ Low Capacitance: 15pF
✔ RoHS Compliant
MECHANICAL CHARACTERISTICS
✔ Molded JEDEC SO-8
✔ Weight 70 milligrams (Approximate)
✔ Available in Lead-Free Pure-Tin Plating(Annealed)
✔ Solder Reflow Temperature:
Pure-Tin - Sn, 100: 260-270°C
✔ Consult Factory for Leaded Device Availability
✔ Flammability Rating UL 94V-0
✔ 12mm Tape and Reel Per EIA Standard 481
✔ Marking: Marking Code, Logo, Date Code & Pin One Defined By Dot on Top of Package
05208
PIN CONFIGURATION
SO-8
124
8
3
5
6
7
GND I/O 4 I/O 3 GND
I/O 1 +VREF +VREF I/O 2
205208.R3 12/07 www.protekdevices.com
SRDA3.3-4
DEVICE CHARACTERISTICS
0.1 1 10 100 1,000 10,000
td - Pulse Duration - µs
500W 8/20µs Waveform
10
100
1,000
10,000
PPP - Peak Pulse Power - Watts
FIGURE 1
PEAK PULSE POWER VS PULSE TIME
0 5 10 15 20 25 30
t - Time - µs
0
20
40
60
80
100
120
IPP - Peak Pulse Current - % of IPP
TEST
WAVEFORM
PARAMETERS
tf = 8µs
td = 20µs
tfPeak Value IPP
e-t
td = t IPP/2
FIGURE 2
PULSE WAVE FORM
MAXIMUM RATINGS @ 25°C Unless Otherwise Specified
Operating Temperature
SYMBOL VALUE
-55 to 150 °C
°C
-55 to 150
UNITS
TL
TSTG
PARAMETER
Storage Temperature
Peak Pulse Power (tp = 8/20µs) - See Figure 1 PPP 500 Watts
Maximum Forward Voltage @ 10mA (See Note 1) Volts1.5VF
Note 1: Measured between pins 8 or 5 to 1, 2, 3, 4, 6 and 7.
ELECTRICAL CHARACTERISTICS PER LINE @ 25°C Unless Otherwise Specified
Note 1: Capacitance measured at VWM = VCC connected between I/O pins to pin 8 and 5 (Gnd). VR = VWM @ 1MHz. As shown in Figure 5, REF1 is
connected to ground, REF2 is connected to +VCC, and input applies to VCC = 5V, Vsign = mV, F = 1 MHz.
PART
NUMBER
DEVICE
MARKING
MINIMUM
BREAKDOWN
VOLTAGE
@ 1mA
V(BR)
VOLTS
MAXIMUM
CLAMPING
VOLTAGE
(See Fig. 2)
@ IP = 1A
VC
VOLTS
MAXIMUM
CLAMPING
VOLTAGE
(See Fig. 2)
@8/20µs
VC @ IPP
MAXIMUM
CAPACITANCE
(See Note 1)
(See Figure 5)
@0V, 1 MHz
Cj(SD)
pF
SRDA3.3-4 SRD 4.0 5.3 10.9V @ 43.0A 15
MAXIMUM
LEAKAGE
CURRENT
@VWM
ID
µA
1
RATED
STAND-OFF
VOLTAGE
VWM
VOLTS
3.3
305208.R3 12/07 www.protekdevices.com
SRDA3.3-4
GRAPHS
FIGURE 4
INPUT CAPACITANCE CIRCUIT
G
REF2
+VCC
REF1
VR
I/O
0 25 50 75 100 125 150
TL - Lead Temperature - °C
20
40
60
80
100
% Of Rated Power
Peak Pulse Power
8/20µs
Average Power
FIGURE 3
POWER DERATING CURVE
0
405208.R3 12/07 www.protekdevices.com
SRDA3.3-4
APPLICATION NOTE
The SRDA3.3-4 is a low capacitance, unidirectional TVS array that is designed to protect I/O or high speed data lines from the damaging effects of
ESD or EFT. This product has a surge capability of 500 Watts PPP per line for an 8/20µs waveshape and offers ESD protection > 40kV.
DIFFERENTIAL-MODE CONFIGURATION (Figure 1)
Ideal for use in USB applications, the SRDA3.3-4 provides up to four
(4) lines of protection in a differential-mode configuration as depicted
in Figure 1.
Circuit connectivity is as follows:
✔Pins 1, 4, 6 and 7 are connected to the data lines.
✔Pins 5 and 8 are connected to ground.
✔Pins 2 and 3 are connected to the databus.
DIFFERENTIAL-MODE CONFIGURATION (Figure 2)
The SRDA3.3-4 also provides up to four (4) lines of protection in a
differential-mode configuration as depicted in Figure 2 for T1/E1
applications.
Circuit connectivity is as follows:
✔Pins 1, 4, 6 and 7 are connected to the data lines.
✔Pins 5 and 8 are connected to ground.
✔Pins 2 and 3 are connected to the databus.
CIRCUIT BOARD LAYOUT RECOMMENDATIONS
Circuit board layout is critical for Electromagnetic Compat-
ibility (EMC) protection. The following guidelines are
recommended:
✔The protection device should be placed near the input
terminals or connectors, the device will divert the
transient current immediately before it can be coupled
into the nearby traces.
✔The path length between the TVS device and the
protected line should be minimized.
✔All conductive loops including power and ground
loops should be minimized.
✔The transient current return path to ground should be
kept as short as possible to reduce parasitic induc-
tance.
✔Ground planes should be used whenever possible.
For multilayer PCBs, use ground vias.
Figure 2. Typical Differential-Mode T1/E1 Protection
41
2
8
7
6
5
3
PTC
PTC
PTC
PTC
PLC01-
6
PLC01-
6
GND
GND
TRING
TTIP
RTIP
RRING
T1/E1 TRANSCEIVER
41
2
8
7
6
5
3
Figure 1. Typical Differential-Mode USB Protection
USB PORT VBUS
GND
D+
D-
USB PORT VBUS
GND
D+
D-
USB CONTROLLER
VBUS
GNDGND
505208.R3 12/07 www.protekdevices.com
SRDA3.3-4
SO-8 PACKAGE OUTLINE & DIMENSIONS
COPYRIGHT © ProTek Devices 2007
SPECIFICATIONS: ProTek reserves the right to change the electrical and or mechanical characteristics described herein without notice (except JEDEC).
DESIGN CHANGES: ProTek reserves the right to discontinue product lines without notice, and that the final judgement concerning selection and specifications is
the buyer’s and that in furnishing engineering and technical assistance, ProTek assumes no responsibility with respect to the selection or specifications of such
products.
ProTek Devices
2929 South Fair Lane, Tempe, AZ 85282
Tel: 602-431-8101 Fax: 602-431-2288
E-Mail: sales@protekdevices.com
Web Site: www.protekdevices.com
TAPE & REEL/BULK ORDERING NOMENCLATURE
1. Surface mount product is taped and reeled in accordance with EIA-481.
2. Suffix-T7 = 7 Inch Reel - 1,000 pieces per 12mm tape,
i.e. SRDA3.3-4-T7.
3. Suffix-T13 = 13 Inch Reel - 2,500 pieces per 12mm tape,
i.e., SRDA3.3-4-T13.
4. Suffix - LF = Lead-Free, Pure-Tin Plating, i.e., SRDA3.3-4-LF-T7.
5. No Suffix = Product Shipped in Tubes of 98 pcs per Tube.
A
B
C
D
F
G
J
K
P
R
4.80
3.80
1.35
0.35
0.40
1.27 BSC
0.18
0.10
5.80
0.25
5.00
4.00
1.75
0.49
1.250
1.27 BSC
0.25
0.25
6.20
0.50
0.189
0.150
0.054
0.014
0.016
0.05 BSC
0.007
0.004
0.229
0.010
0.196
0.157
0.068
0.019
0.049
0.05 BSC
0.009
0.008
0.244
0.019
DIM MIN MAX MIN MAX
MILLIMETERS INCHES
PACKAGE DIMENSIONS
NOTES
1. - T - = Seating Plane and Datum Surface.
2. Dimensions “A” and “B” are Datum.
3. Dimensions “A” and “B” do not include mold protrusion.
4. Maximum mold protrusion is 0.015” (0.380 mm) per side.
5. Dimensioning and tolerances per ANSI Y14.5M, 1982.
6. Dimensions are exclusive of mold flash and metal burrs.
-A-
85
14
-B - P
G
D
-T-
C
KJ
R x 45°
0° - 10°
F
4 PL
0.010 (0.25 MM) MM
B
+
8 PL
0.010 (0.25 MM) MS
B
+S
AT
PACKAGE OUTLINE SO-8
0.050 ± 0.005
0.030 ± 0.005
0.245 MIN
0.160 ± 0.005
0.045 ± 0.005
MOUNTING PAD
Outline & Dimensions: Rev 1 - 11/01, 06009
