HSSR-711X Agilent(Hewlett-Packard), HSSR-711X Datasheet - Page 12

• Manufacturer Part Number: HSSR-711X
• Description: 90 V/1.0 W/ Hermetically Sealed/ Power MOSFET Optocoupler
• Manufacturer: Agilent(Hewlett-Packard)

610 mA. A check with Figure 4
shows that the output power
dissipation at T
610 mA, will be limited to less
than 0.35 W. This yields an R
0.94
Design Considerations
for Replacement of
Electro-Mechanical
Relays
The HSSR-7110 family can
replace electro-mechanical relays
with comparable output voltage
and current ratings. The following
design issues need to be consid-
ered in the replacement circuit.
Input Circuit: The drive circuit
of the electro-mechanical relay
coil needs to be modified so that
the average forward current
driving the LED of the HSSR-
7110 does not exceed 20 mA. A
nominal forward drive current of
10 mA is recommended. A
recommended drive circuit with 5
volt V
shown in Figure 1. If higher V
voltages are used, adjust the
current limiting resistor to a
nominal LED forward current of
10 mA. One important considera-
tion to note is that when the LED
is turned off, no more than 0.6
volt forward bias should be
applied across the LED. Even a
few microamps of current may be
sufficient to turn on the HSSR-
7110, although it may take a
considerable time. The drive
circuit should maintain at least 5
mA of LED current during the ON
condition. If the LED forward
current is less than the 5 mA
level, it will cause the HSSR-7110
to turn on with a longer delay. In
addition, the power dissipation in
the output power MOSFETs
increases, which, in turn, may
violate the power dissipation
guidelines and affect the
reliability of the device.
CC
.
and CMOS logic gates is
A
= 95 C and I
SS
O
CC
=
of
Output Circuit: Unlike electro-
mechanical relays, the designer
should pay careful attention to the
output on-resistance of solid state
relays. The previous section, ”On-
Resistance and Rating Curves”
describes the issues that need to
be considered. In addition, for
strictly dc applications the
designer has an advantage using
Connection B which has twice the
output current rating as Connec-
tion A. Furthermore, for dc-only
applications, with Connection B
the on-resistance is considerably
less when compared to
Connection A.
Output over-voltage protection is
yet another important design
consideration when replacing
electro-mechanical relays with the
HSSR-7110. The output power
MOSFETs can be protected using
Metal oxide varistors (MOVs) or
TransZorbs against voltage surges
that exceed the 90 volt output
withstand voltage rating.
Examples of sources of voltage
surges are inductive load kick-
backs, lightning strikes, and
electro-static voltages that exceed
the specifications on this data
sheet. For more information on
output load and protection refer
to Application Note 1047.
References:
1. Application Note 1047, ”Low
2. Reliability Data for HSSR-7110.
MOV is a registered trademark of GE/RCA
Solid State.
TransZorb is a registered trademark of
General Semiconductor.
On-Resistance Solid State
Relays for High Reliability
Applications.”
MIL-PRF-38534 Class H
and DSCC SMD Test
Program
Hewlett-Packard’s Hi-Rel
Optocouplers are in compliance
with MIL-PRF-38534 Class H.
Class H devices are also in
compliance with DSCC drawing
5962-93140.
Testing consists of 100% screen-
ing and quality conformance
inspection to MIL-PRF-38534.
www.hp.com/go/isolator
For technical assistance or the location of
your nearest Hewlett-Packard sales office,
distributor or representative call:
Americas/Canada: 1-800-235-0312 or
408-654-8675
Far East/Australasia: Call your local HP
sales office.
Japan: (81 3) 3335-8152
Europe: Call your local HP sales office.
Data subject to change.
Copyright © 1998 Hewlett-Packard Co.
Obsoletes 5965-1142E
Printed in U.S.A. 5968-0470E (7/98)