SL05 ON Semiconductor, SL05 Datasheet - Page 4

• Manufacturer Part Number: SL05
• Description: Tvs Single Line Low Capacitance 5 V
• Manufacturer: ON Semiconductor

Applications Background
designed to protect sensitive electronics such as
communications systems, computers, and computer
peripherals against damage due to ESD conditions or
transient voltage conditions. Because of their low
capacitance value (less than 5 pF), they can be used in high
speed I/O data lines. Low capacitance is achieved by
integrating a compensating diode in series with the TVS
which is basically based in the below theoretical principle:
•
•
series device:
line protected by the SL05T1 series device, the TVS is
reversed−biased while the compensation diode is
forward−biased so the resulting current due to the transient
voltage is drained to ground.
device is connected in inverse−parallel with reference to the
first one, the Figure 6 illustrates the inverse−parallel
connection for bi−directional or unidirectional lines:
For optimizing the protection, it is recommended to use ground planes and short path lengths to minimize the PCB’s ground inductance.
This new family of TVS devices (SL05T1 series) are
The Figure 5 shows the integrated solution of the SL05T1
In the case that an over−voltage condition occurs in the I/O
If protection in both polarities is required, an additional
Capacitance in parallel: CT = C1+C2+....+Cn
Capacitance in series: 1/CT = (1/C1)+(1/C2)+....+(1/Cn)
INPUT
COMPENSATING
DIODE
Figure 5.
TVS
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SL05T1 Series
Figure 8.
4
connect a fast switching steering diode in parallel with the
SL05T1 series device. When the steering diode is
forward−biased, the TVS will avalanche and conduct in
reverse direction. It is important to note that by adding a
steering diode, the effective capacitance in the circuit will be
increased, therefore the impact of adding a steering diode
must be taken in consideration to establish whether the
incremental capacitance will affect the circuit functionality
or not. The Figure 7 shows the connection between the
steering diode and the SL05T1 series device:
device can be utilized, is to protect multiple I/O lines. The
protection in each of the I/O lines is achieved by connecting
two devices in inverse−parallel. The Figure 8 illustrates how
multiple I/O line protection is achieved:
An alternative solution to protect unidirectional lines, is to
Another typical application in which the SL05T1 series
1
2
STEERING DIODE
SL05T1 DEVICE
Figure 6.
Figure 7.
3
3
1
2
OUTPUT