HCPL-810J Datasheet, PDF (16/16 Pages) Agilent(Hewlett-Packard) – PLC Powerline DAA IC

78L05
5V
VOUT
VIN
GND
+
C* 470 µH 120 mA
X2 1.5 µF/3.3 µF
630 mA
L
100 nF
-
1000 µF
9.1 V 1 W
VARISTOR
220 kÙ
N
GND2
* 1.5µF X2 for 230V mains, 3.3µF X2 for 110V mains
Figure 22. A simple low cost non-isolated power supply.
V_CC2 Power Supply Requirements
The recommended voltage
regulator to supply V_CC2 is a
low cost 78L05 or equivalent. To
minimize harmonic distortion, it
is recommended to connect a
tantalum decoupling capacitor
of at least 10 µF together with
a 100 nF ceramic capacitor in
parallel. The capacitors should
be positioned as close as
possible to the supply input pin.
The supply voltage for the
regulator can be supplied from
the system level power supply
transformer (powerline side
winding). Alternatively, the
supply can be derived directly
from the powerline via a simple
low cost circuit as shown in
Figure 22.
Thermal Considerations
The high efficiency line driver
used in the HCPL- 810J ensures
minimum internal power
dissipation, even for high peak
output currents. Despite this,
operating the line driver
continuously with high output
currents at elevated ambient
temperatures can cause the
peak junction temperature to
exceed 125°C and/or resulting
in the triggering of the thermal
protection.
To prevent this from happening,
when operating the line driver
continuously with high output
currents, an ambient
temperature derating factor
needs to be applied. A typical
derating curve is shown in
Figure 23.
In this case the assumption is
that the transmitter is operating
continuously in still air with a
typical 2- layer Printed- Circuit
Board (PCB). However, it should
be noted that operating the
transmitter discontinuously for
short periods of time will allow
lower derating or even no
derating at all. Conversely
operating the line driver
continuously with a poor PCB
layout and/or with restricted air
convection could result in the
requirement for a larger
derating factor.
1.4
1.2
1
0.8
0.6
0.4
0.2
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Data subject to change.
Copyright 2003 Agilent Technologies, Inc.
March 18, 2004
5989-0717EN
0
-40
-15
10
35
60
85
T_A – AMBIENT TEMPERATURE – °C
Figure 23. Power derating vs. temperature.