ncs5650 ON Semiconductor, ncs5650 Datasheet - Page 8

• Manufacturer Part Number: ncs5650
• Description: Ncs5650 2 Amp Plc Line Driver
• Manufacturer: ON Semiconductor

Thermal Shutdown and Thermal Warning Flag
the amplifier will go into shutdown to prevent damage.
Under these conditions pin 17 the TSD flag (Thermal Shut
Down) will go logic High. Thermal shutdown takes place at
an internal junction temperature of approximately 160°C;
the amplifier will recover to the Enabled mode when the
junction temperature cools back down to approximately
145°C.
mode by monitoring the junction temperature via the
Thermal Warning feature. Figure 8 shows how the user can
select any junction temperature (T
to 145°C by applying the appropriate voltage to pin 14. A
simple way to implement this feature is by setting the ratio
of a voltage divider between V
negative supply, pin 10 or 11). The voltage ratio required to
program the thermal warning of the NCS5650 can be
calculated using the following equation:
temperature to the required voltage on pin 14 (T
In the event load conditions cause internal over−heating
The user has the option to avoid entering into the TSD
Figure 8 illustrates the linearity of the internal junction
20
15
10
5
0
0
VTW = 6.665 x 10
0.25
V
V
EE
CC
R9
R10
0.5
CURRENT LIMITS (A)
0.75
Figure 6.
Figure 7.
14
−3
(T
1
CC
J
) + 1.72
warn
(pins 6,7) and V
1.25
) in the range 105°C
1.5
V
O
warn
1.75
EE
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).
(the
2
8
Virtual Common (V
virtual common for implementing the 4th−order CENELEC
filter when operating on single−sided power supply. When
operating on balanced split supplies it is recommended to
use the power supply common for the filter implementation
and to leave V
Digital Power Supply GND−Reference and Translators
digital GND are not always at the same potential. To
minimize GND loop issues, the NCS5650 has a separate
GND pin (pin 20) which should be used to reference the
digital supply and the warning flags (pins 16, 17, and 18). In
most applications this would be the same GND reference
used for the PLC modem. Please note that at some point in
the application digital GND and analog GND must be tied
together.
2.75
2.25
1.75
1.25
The principal purpose of V
In many mixed signal applications analog GND and
2.5
1.5
3
2
1
−40 −20
com
0
floating.
com
20
Figure 8.
)
40
T
J
com
(°C)
60
is to provide a convenient
80
100 120
140