uClamp3304A Datasheet

uClamp3304A
µClampTM
4-Line ESD protection Array
PROTECTION PRODUCTS - MicroClampTM
Description
Features
The µClampTM series of TVS arrays are designed to protect sensitive electronics from damage or latch-up due
to ESD. They are designed for use in applications where
board space is at a premium. Each device requires less
than 2.9mm2 of PCB area and will protect up to four
lines. They are unidirectional devices and may be used
on lines with positive signal polarities.
The µclampTM3304A is constructed using Semtech’s proprietary EPD process technology. The EPD process provides low standoff voltages with significant reductions in
leakage currents and capacitance over silicon-avalanche
diode processes. They feature a true operating voltage
of 3.3 volts for superior protection when compared to
traditional pn junction devices.
These devices may be used to meet the immunity requirements of IEC 61000-4-2, level 4. They offer desirable characteristics for board level protection including
fast response time, low operating and clamping voltage,
and no device degradation. The small SC89 package
makes them ideal for use in portable electronics such as
cell phones, PDAs, notebook computers, and digital cameras.
‹ Transient protection for data lines to
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IEC 61000-4-2 (ESD) ±15kV (air), ±8kV (contact)
IEC 61000-4-4 (EFT) 40A (5/50ns)
Protects four unidirectional I/O lines
1.7 x 1.7 x 0.6mm
Ultra-small SC-89 package (1.7
0.6mm)
2
requires less than 2.9mm of PCB area
Working voltage: 3.3V
Low leakage current
Low operating and clamping voltages
Solid-state silicon-avalanche technology
Mechanical Characteristics
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SC-89 (SOT-666) package
Molding compound flammability rating: UL 94V-0
Marking: Marking Code
Lead Finish: Matte Tin
RoHS Compliant
Weight: 2.9mg (typical)
Packaging: Tape and Reel
Applications
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Dimensions
Cellular Handsets and Accessories
Cordless Phones
Notebooks and Handhelds
Portable Instrumentation
Digital Cameras
Peripherals
MP3 Players
Schematic & PIN Configuration
1.70
0.50
1.25
1.70
0.30
0.60
Maximum Dimensions (mm)
Revision 01/18/08
SC-89 (Top View)
1
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µClamp3304A
PROTECTION PRODUCTS
Absolute Maximum Rating
R ating
Symbol
Value
Units
Peak Pulse Power (tp = 8/20µs)
Pp k
40
Watts
Maximum Peak Pulse Current (tp = 8/20µs)
Ip p
5
Amps
ESD per IEC 61000-4-2 (Air)
ESD per IEC 61000-4-2 (Contact)
V PP
+/- 20
+/- 15
kV
Lead Soldering Temperature
TL
260 (10 sec.)
°C
Operating Temperature
TJ
-55 to +125
°C
TSTG
-55 to +150
°C
Storage Temperature
Electrical Characteristics (T=25oC)
Parameter
Reverse Stand-Off Voltage
Symbol
Conditions
Minimum
Typical
VRWM
Maximum
Units
3.3
V
Punch-Through Voltage
V PT
IPT = 2µA
3.5
V
Snap -Back Voltage
VSB
ISB = 50mA
2.8
V
Reverse Leakage Current
IR
VRWM = 3.3V
Clamp ing Voltage
VC
Clamp ing Voltage
0.5
µA
IPP = 1A, tp = 8/20µs
5.5
V
VC
IPP = 5A, tp = 8/20µs
8.0
V
Forward Clamp ing Voltage
VF
IPP = 1A, tp = 8/20µs
2.4
V
30
pF
Cj
I/O p in to Gnd
VR = 0V, f = 1MHz
22
Junction Cap acitance
I/O p in to Gnd
VR = 3.3V, f = 1MHz
14
 2008 Semtech Corp.
2
0.05
pF
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µClamp3304A
PROTECTION PRODUCTS
Typical Characteristics
Non-Repetitive Peak Pulse Power vs. Pulse Time
Power Derating Curve
1
110
100
% of Rated Power or IPP
Peak Pulse Power - P PP (kW)
90
0.1
80
70
60
50
40
30
20
10
0
0.01
0.1
1
10
100
0
1000
25
50
75
100
125
150
o
Ambient Temperature - TA ( C)
Pulse Duration - tp (µs)
Clamping Voltage vs. Peak Pulse Current
Junction Capacitance vs. Reverse Voltage
12
25.0
f = 1 MHz
Clamping Voltage - VC (V)
10
20.0
Capacitance - Cj (pF)
8
6
4
Waveform
Parameters:
tr = 8µs
td = 20µs
2
15.0
10.0
5.0
0
0
1
2
3
4
0.0
5
0
Peak Pulse Current - IPP (A)
Forward Voltage vs Forward Current
0.5
1
1.5
2
2.5
Reverse Voltage - VR (V)
3
3.5
ESD Clamping
(8kV Contact per IEC 61000-4-2)
7
Forward Voltage - VF (V)
6
5
4
3
2
Waveform
Parameters:
tr = 8µs
td = 20µs
1
0
0
1
2
3
4
5
6
Forward Current - IF (A)
 2008 Semtech Corp.
3
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µClamp3304A
PROTECTION PRODUCTS
Applications Information
Circuit Diagram
Device Connection for Protection of Four Data Lines
These devices are designed to protect up to four
unidirectional data lines. The device is connected as
follows:
1
3
4
6
1. Unidirectional protection of four I/O lines is
achieved by connecting pins 1, 3, 4, and 6 to the
data lines. Pins 2 and 5 are connected to ground.
The ground connection should be made directly to
the ground plane for best results. The path length
is kept as short as possible to reduce the effects
of parasitic inductance in the board traces.
2, 5
Due to the “snap-back” characteristics of the low
voltage TVS, it is not recommended that any of the I/O
lines be directly connected to a DC source greater than
snap-back votlage (VSB) as the device can latch on as
described below.
Protection of Four Unidirectional Lines
EPD TVS Characteristics
The SMF3.3 is constructed using Semtech’s proprietary EPD technology. The structure of the EPD TVS is
vastly different from the traditional pn-junction devices.
At voltages below 5V, high leakage current and junction
capacitance render conventional avalanche technology
impractical for most applications. However, by utilizing
the EPD technology, the SMF3.3 can effectively operate at 3.3V while maintaining excellent electrical
characteristics.
The EPD TVS employs a complex nppn structure in
contrast to the pn structure normally found in traditional silicon-avalanche TVS diodes. Since the EPD
TVS devices use a 4-layer structure, they exhibit a
slightly different IV characteristic curve when compared
to conventional devices. During normal operation, the
device represents a high-impedance to the circuit up to
the device working voltage (VRWM). During an ESD
event, the device will begin to conduct and will enter a
low impedance state when the punch through voltage
(VPT) is exceeded. Unlike a conventional device, the low
voltage TVS will exhibit a slight negative resistance
characteristic as it conducts current. This characteristic aids in lowering the clamping voltage of the device,
but must be considered in applications where DC
voltages are present.
 2008 Semtech Corp.
When the TVS is conducting current, it will exhibit a
slight “snap-back” or negative resistance characteristics due to its structures. This point is defined on the
curve by the snap-back voltage (VSB) and snap-back
current (ISB). To return to a non-conducting state, the
current through the device must fall below the ISB
(approximately <50mA) and the voltage must fall below
the VSB (normally 2.8 volts for a 3.3V device). If a 3.3V
TVS is connected to 3.3V DC source, it will never fall
below the snap-back voltage of 2.8V and will therefore
stay in a conducting state.
4
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µClamp3304A
PROTECTION PRODUCTS
Typical Applications
uClamp3304A
Circuit Board Layout Recommendations for Suppression of ESD.
Matte Tin Lead Finish
Matte tin has become the industry standard lead-free
replacement for SnPb lead finishes. A matte tin finish
is composed of 100% tin solder with large grains.
Since the solder volume on the leads is small compared to the solder paste volume that is placed on the
land pattern of the PCB, the reflow profile will be
determined by the requirements of the solder paste.
Therefore, these devices are compatible with both
lead-free and SnPb assembly techniques. In addition,
unlike other lead-free compositions, matte tin does not
have any added alloys that can cause degradation of
the solder joint.
Good circuit board layout is critical for the suppression
of ESD induced transients. The following guidelines are
recommended:
z Place the TVS near the input terminals or connectors to restrict transient coupling.
z Minimize the path length between the TVS and the
protected line.
z Minimize all conductive loops including power and
ground loops.
z The ESD transient return path to ground should be
kept as short as possible.
z Never run critical signals near board edges.
z Use ground planes whenever possible.
 2008 Semtech Corp.
5
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µClamp3304A
PROTECTION PRODUCTS
Applications Information - Spice Model
Figure 1 - µClamp3304A Spice Model
Table 1 - µClamp3304A Spice Parameters
 2008 Semtech Corp.
Parameter
Unit
D1 (T VS)
D2 (LCR D)
IS
Amp
1.00E-20
1.00E-20
BV
Volt
3.47
8
VJ
Volt
14
0.70
RS
Ohm
0.737
0.795
IB V
Amp
1.0E-3
1.0E-3
CJO
Farad
14.53E-12
6E-12
TT
sec
2.541E-9
2.541E-9
M
--
0.152
0.152
N
--
1.1
1.1
EG
eV
1.11
1.11
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µClamp3304A
PROTECTION PRODUCTS
Outline Drawing - SC-89 (SOT-666)
D
A
D
N
E/2
E1
E
L
2
1
e
c
Nxb
B
aaa
C A-B D
A
DIM
A
b
c
D
E
E1
e
L
L1
N
aaa
C
L1
DIMENSIONS
INCHES
MILLIMETERS
MIN NOM MAX MIN NOM MAX
.019
.024
.005
.012
.003
.007
.059 .063 .067
.061 .063 .067
.043 .047 .049
.020 BSC
.003 .008 .012
.003 .006 .008
6
.004
0.50
0.60
0.15
0.30
0.10
0.18
1.50 1.60 1.70
1.55 1.60 1.70
1.10 1.20 1.25
0.50 BSC
0.10 0.20 0.30
0.10 0.15 0.20
6
0.10
NOTES:
1. CONTROLLING DIMENSIONS ARE IN MILLIMETERS (ANGLES IN DEGREES).
2. DIMENSIONS "E1" AND "D" DO NOT INCLUDE MOLD FLASH, PROTRUSIONS
OR GATE BURRS.
Land Pattern - SC-89 (SOT-666)
X
Y
Z
C
DIM
C
P
G
X
Y
Z
G
Y
DIMENSIONS
INCHES
MILLIMETERS
(.057)
.020
.024
.012
.033
.090
(1.45)
0.50
0.60
0.30
0.85
2.30
P
NOTES:
1. THIS LAND PATTERN IS FOR REFERENCE PURPOSES ONLY
CONSULT YOUR MANUFACTURING GROUP TO ENSURE YOUR
COMPANY'S MANUFACTURING GUIDELINES ARE MET.
 2008 Semtech Corp.
7
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µClamp3304A
PROTECTION PRODUCTS
Marking Code
Ordering Information
SS
Part Number
Working
Voltage
uClamp 3304A.TCT
3.3V
Device Qty per
Marking
Reel
SS
3,000
Reel
Size
7 Inch
Note: Lead finish is lead-free matte tin
MicroClamp, uClamp and µClamp are trademarks of Semtech
Corporation
Note:
(1) Device is symmetrical so there is no pin 1 identifier
Tape and Reel Specification
SS
SS
SS
Tape Specifications and Device Orientation
Contact Information
Semtech Corporation
Protection Products Division
200 Flynn Rd., Camarillo, CA 93012
Phone: (805)498-2111 FAX (805)498-3804
 2008 Semtech Corp.
8
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