Features
■ Superior circuit protection
■ Overcurrent and overvoltage protection
■ Blocks surges up to rated limits
■ High speed performance
■ Small SMT package
■ RoHS compliant*
■ Agency recognition:
Applications
■ Set top box LNB ports
■ Protection modules and dongles
■ Process control equipment
■ Test and measurement equipment
■ General electronics
TBU-KE Series - TBU® High Speed Protectors
*RoHS Directive 2002/95/EC Jan 27, 2003 including Annex.
Specifi cations are subject to change without notice.
Customers should verify actual device performance in their specifi c applications.
General Information
The TBU-KE Series of Bourns® TBU®
(Transient Blocking Unit) products are very
low capacitance unidirectional high speed
surge protection components designed to protect
against faults caused by short circuits, AC
power cross, induction and lightning surges.
The TBU-KE is a unidirectional TBU® device: the TBU® protector will trip in less than
1 μs when the current reaches the maximum value in one direction only, that is when
Pin 1 is positive in voltage with respect to Pin 2. No current limiting exists in the oppo-
site polarity, and the TBU® protector appears as resistive in nature. The reverse current
should not exceed the maximum trip current level of the TBU® device. An external
diode may be used to prevent reverse current in DC biased applications.
The TBU® protector blocks surges and provides an effective barrier behind which sen-
sitive electronics will not be exposed to large voltages or currents during surge events.
After the surge, the TBU® device resets when the voltage across the TBU® device falls
to the Vreset level. The TBU® device will automatically reset on lines which have no DC
bias or have DC bias below Vreset (such as unpowered signal lines).
The TBU® device is provided in a surface mount DFN package and meets industry
standard requirements such as RoHS and Pb Free solder refl ow profi les.
Agency Approval
Description
UL File Number: E315805
Absolute Maximum Ratings (@ TA = 25 °C Unless Otherwise Noted)
Symbol Parameter Part Number Value Unit
Vimp Peak impulse voltage withstand with duration less than 10 ms
TBU-KE025-xxx-WH
TBU-KE040-xxx-WH
TBU-KE050-xxx-WH
250
400
500
V
Vrms Continuous A.C. RMS voltage
TBU-KE025-xxx-WH
TBU-KE040-xxx-WH
TBU-KE050-xxx-WH
100
200
250
V
Top Operating temperature range -40 to +85 °C
Tstg Storage temperature range -65 to +150 °C
*RoHS COMPLIANT
E2550
0072
TBU
®
Device
Line Side
12
Load Side
Asia-Pacifi c: Tel: +886-2 2562-4117 • Fax: +886-2 2562-4116
Europe: Tel: +41-41 768 5555 • Fax: +41-41 768 5510
The Americas: Tel: +1-951 781-5500 • Fax: +1-951 781-5700
www.bourns.com
Specifi cations are subject to change without notice.
Customers should verify actual device performance in their specifi c applications.
TBU-KE Series - TBU® High Speed Protectors
Electrical Characteristics (@ TA = 25 °C Unless Otherwise Noted)
Symbol Parameter Part Number Min. Typ. Max. Unit
Itrigger
Current required for the device to go from operating state to
protected state
TBU-KExxx-050-WH
TBU-KExxx-100-WH
TBU-KExxx-200-WH
TBU-KExxx-300-WH
TBU-KExxx-500-WH
50
100
200
300
500
75
150
300
450
750
100
200
400
600
1000
mA
Rdevice
Series resistance of
the TBU® device
Vimp = 250 V Itrigger (min.) = 50 mA
Vimp = 250 V Itrigger (min.) = 100 mA
Vimp = 250 V Itrigger (min.) = 200 mA
Vimp = 250 V Itrigger (min.) = 300 mA
Vimp = 250 V Itrigger (min.) = 500 mA
Vimp = 400 V Itrigger (min.) = 50 mA
Vimp = 400 V Itrigger (min.) = 100 mA
Vimp = 400 V Itrigger (min.) = 200 mA
Vimp = 400 V Itrigger (min.) = 300 mA
Vimp = 400 V Itrigger (min.) = 500 mA
Vimp = 500 V Itrigger (min.) = 50 mA
Vimp = 500 V Itrigger (min.) = 100 mA
Vimp = 500 V Itrigger (min.) = 200 mA
Vimp = 500 V Itrigger (min.) = 300 mA
Vimp = 500 V Itrigger (min.) = 500 mA
TBU-KE025-050-WH
TBU-KE025-100-WH
TBU-KE025-200-WH
TBU-KE025-300-WH
TBU-KE025-500-WH
TBU-KE040-050-WH
TBU-KE040-100-WH
TBU-KE040-200-WH
TBU-KE040-300-WH
TBU-KE040-500-WH
TBU-KE050-050-WH
TBU-KE050-100-WH
TBU-KE050-200-WH
TBU-KE050-300-WH
TBU-KE050-500-WH
12.5
6.3
3.4
2.4
1.8
13.0
6.8
3.9
3.0
2.3
13.7
7.5
4.6
3.6
3.0
14.6
7.5
4.1
3.1
2.3
15.2
8.1
4.7
3.7
2.9
16.0
8.9
5.5
4.5
3.6
Ω
tblock Time for the device to go from normal operating state to protected state 1 µs
IQCurrent through the triggered TBU® device with 50 Vdc circuit voltage 0.25 0.50 1.00 mA
Vreset
Voltage below which the triggered TBU® device will transition to normal operating
state 12 16 20 V
Rth(j-l) Junction to package pads - FR4 using recommended pad layout 116 °C/W
Rth(j-l) Junction to package pads - FR4 using heat sink on board (6 cm2) 96 °C/W
TBU-KE Series - TBU® High Speed Protectors
Specifi cations are subject to change without notice.
Customers should verify actual device performance in their specifi c applications.
Reference Application
The TBU® device can be used to protect against excessive
voltage surges in DC biased equipment, as shown in the fi gure
below. Diode D1 prevents reverse voltage surges from damaging
the equipment, and the TBU® protector prevents any positive
surges from causing damage. An overvoltage protection device,
such as an MOV, may be used to provide additional overvolt-
age protection if the surge voltage is likely to be above the
maximum rating of the TBU® device. D1 reverse voltage rating
should be greater than that of the OVP device at the maximum
surge current level. Typically, a 1N4007 is a suitable choice. D2
should be chosen to be above the normal working voltage of
the protected device, but below its absolute maximum rating.
The TBU® device is a silicon-based, solid-state, resettable
device which is placed in series with a signal path. The TBU®
device operates in approximately 1 µs - once line current
exceeds the TBU® device’s trigger current Itrigger. When oper-
ated, the TBU® device restricts line current to less than 1 mA
typically. When operated, the TBU® device will block all system
voltages and any other voltages including the surge up to
rated limits.
After the surge, the TBU® device resets when the voltage
across the TBU® device falls to the Vreset level. The TBU® de-
vice will automatically reset on lines which have no DC bias or
have DC bias below Vreset (such as unpowered signal lines).
If the line has a normal DC bias above Vreset, the voltage
across the TBU® device may not fall below Vreset after the
surge. In such cases, special care needs to be taken to ensure
that the TBU® device will reset, otherwise an automatic or
manual power down will be required. Bourns application
engineers can provide further assistance.
Basic TBU Operation
Performance Graphs
V-I Characteristic - TBU-KE050-300-WH (Pin 2-1) Typical Trigger Current vs. Temperature
CURRENT
(100 mA/div.)
VOLTAGE
(5 v/div.)
VRESET
ITRIGGER 1.8
1.6
1.4
1.2
1.0
0.8
0.6
0.4
0.2
0.0
-75 -50 -25 0 25 50 75 100 125 150
Junction Temperature (°C)
Normalized Trip Current (A)
Equip.
OVP
TBU®Device
Line
Side
12
D2
D1
Refl ow Profi le
Profi le Feature Pb-Free Assembly
Average Ramp-Up Rate (Tsmax to Tp) 3 °C/sec. max.
Preheat
- Temperature Min. (Tsmin)
- Temperature Max. (Tsmax)
- Time (tsmin to tsmax)
150 °C
200 °C
60-180 sec.
Time maintained above:
- Temperature (TL)
- Time (tL)
217 °C
60-150 sec.
Peak/Classifi cation Temperature (Tp) 260 °C
Time within 5 °C of Actual Peak Temp. (tp) 20-40 sec.
Ramp-Down Rate 6 °C/sec. max.
Time 25 °C to Peak Temperature 8 min. max.
Specifi cations are subject to change without notice.
Customers should verify actual device performance in their specifi c applications.
TBU-KE Series - TBU® High Speed Protectors
Performance Graphs (Continued)
Power Derating Curve Typical Resistance vs. Temperature
No additional PCB Cu
0.5 sq. in. additional PCB CU
Junction Temperature (°C)
20
3.0
2.5
2.0
1.5
1.0
0.5
0.0
40 60 80 100 120 140
Total Max. Power (W)
2.2
1.6
1.8
2.0
1.4
1.2
1.0
0.8
0.6
0.4
0.2
0.0
-75 -50 -25 0 25 50 75 100 125 150
Junction Temperature (°C)
Normalized Resistance (Ω)
PIN 1 & BACKSIDE CHAMFER
2.50 ± 0.10
(.098 ± .004)
0.00 - 0.05
(.000 - .002)
5.00 ± 0.10
(.197 ± .004)
1.00
(.039)
0.85 ± 0.05
(.033 ± .002)
1.90
(.075)
0.60
(.024)
0.30
(.012)
0.30
(.012)
3.05
(.120)
0.75
(.030)
C PIN 1
0.25
(.010)
0.30
(.012)
Product Dimensions
Pad # Pin Out
1 Line Side
2 Load Side
Pad Designation
DIMENSIONS: MM
(INCHES)
Recommended Pad Layout
TBU® protectors have matte-tin termination fi nish. The
suggested layout should use Non-Solder Mask Defi ne (NSMD).
The recommended stencil thickness is 0.10-0.12 mm (.004-
.005 in.) with a stencil opening size 0.025 mm (.0010 in.) less
than the device pad size. As when heat sinking any power
device, it is recommended that wherever possible, extra PCB
copper area is allowed. For minimum parasitic capacitance, do
not allow any signal, ground or power signals beneath any of
the pads of the device.
Specifi cations are subject to change without notice.
Customers should verify actual device performance in their specifi c applications.
12
Dark grey areas show added PCB copper area for better
thermal resistance.
TBU-KE Series - TBU® High Speed Protectors
Thermal Resistance vs. Additional PCB Cu Area
Added Cu Area (Sq. In.)
0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0
100
90
80
60
40
20
0
Thermal Resistance to Ambient (°C/W)
10
30
50
70
Specifi cations are subject to change without notice.
Customers should verify actual device performance in their specifi c applications.
TBU-KE Series - TBU® High Speed Protectors
How to Order
TBU - KE 025 - 500 - WH
TBU® Product
Series
KE = Uni-Series
Impulse Voltage Rating
025 = 250 V
040 = 400 V
050 = 500 V
Trigger Current
050 = 50 mA
100 = 100 mA
200 = 200 mA
300 = 300 mA
500 = 500 mA
Hold to Trip Ratio Suffi x
W = Hold to Trip Ratio
Package Suffi x
H = DFN Package
Typical Part Marking
“TBU” is a registered trademark of Bourns, Inc. in the U.S., Taiwan and European Community.
12/10
Packaging Specifi cations
B
A
DC
NF
G (MEASURED AT HUB)
USER DIRECTION OF FEED
K0
B0
P2
D1
CENTER
LINES OF
CAVITY
EMBOSSMENT
tD
P0
TOP
COVER
TAPE
E
W
P
A0
DIMENSIONS: MM
(INCHES)
A B C D G N
Min. Max. Min. Max. Min. Max. Min. Max. Ref. Ref.
176
(6.929)
178
(7.008)
1.5
(.059)
2.5
(.098)
12.8
(.504)
13.5
(.531)
20.2
(.795) - 16.5
(.650)
102
(4.016)
A0 B
0 D D1 E F
Min. Max. Min. Max. Min. Max. Min. Max. Min. Max. Min. max.
4.2
(.165)
4.4
(.173)
6.65
(.262)
7.05
(.277)
1.5
(.059)
1.6
(.063)
1.5
(.059) -1.65
(.065)
1.85
(.073)
7.4
(.291)
7.6
(.299)
K0P P0 P
2 t W
Min. Max. Min. Max. Min. Max. Min. Max. Min. Max. Min. Max.
1.1
(.043)
1.3
(.051)
7.9
(.311)
8.1
(.319)
3.9
(.159)
4.1
(.161)
1.9
(.075)
2.1
(.083)
0.25
(.010)
0.35
(.014)
15.7
(.618)
16.3
(.642)
QUANTITY: 3000 PIECES PER REEL
PIN 1
MANUFACTURING
DATE CODE
- 1ST DIGIT INDICATES THE YEAR’S 6-MONTH PERIOD.
- 2ND DIGIT INDICATES THE WEEK NUMBER IN THE 6-MONTH PERIOD.
- 3RD & 4TH DIGITS INDICATE SPECIFIC LOT FOR THE WEEK.
6-MONTH PERIOD CODES:
A = JAN-JUN 2009 C = JAN-JUN 2010 E = JAN-JUN 2011
B = JUL-DEC 2009 D = JUL-DEC 2010 F = JUL-DEC 2011
MANUFACTURER’S
TRADEMARK
PRODUCT CODE
- 1ST DIGIT INDICATES PRODUCT FAMILY:
E = TBU-KE SERIES
- 2ND & 3RD DIGITS INDICATE IMPULSE VOLTAGE:
25 = 250 V 40 = 400 V 50 = 500 V
- 4TH & 5TH DIGITS INDICATE TRIGGER CURRENT:
05 = 50 mA 10 = 100 mA 20 = 200 mA
30 = 300 mA 50 = 500 mA
