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Data subject to change. Copyright © 2005-2012 Avago Technologies. All rights reserved. Obsoletes 5989-1944EN
AV02-3801EN - September 12, 2012
Design Considerations for Replacement of Electro-
Mechanical Relays
The HSSR-7110 family can replace electro-mechanical re-
lays with comparable output voltage and current ratings.
The following design issues need to be considered in the
replacement circuit.
Input Circuit: The drive circuit of the electro-mechanical
relay coil needs to be modi ed so that the average for-
ward 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
VCC and CMOS logic gates is shown in Figure 1. If higher
VCC voltages are used, adjust the current limiting resistor
to a nominal LED forward current of 10 mA. One impor-
tant consideration to note is that when the LED is turned
o , no more than 0.6 volt forward bias should be applied
across the LED. Even a few microamps of current may be
su cient 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 in-
creases, which, in turn, may violate the power dissipation
guidelines and a ect the reliability of the device.
Output Circuit: Unlike electromechanical relays, the de-
signer should pay careful attention to the output on-resis-
tance of solid state relays. The previous section, “On- Re-
sistance 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 Connection A. Fur-
thermore, for dc-only applications, with Connection B the
on-resistance is considerably less when compared to Con-
nection 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 kickbacks, lightning
strikes, and electro-static voltages that exceed the speci-
cations on this data sheet. For more information on out-
put load and protection refer to Application Note 1047.
References:
1. Application Note 1047, “Low On-Resistance Solid State
Relays for High Reliability Applications.”
2. Reliability Data for HSSR-7110.
MOV is a registered trademark of GE/RCA Solid State.
TransZorb is a registered trademark of General Semicon-
ductor.
MIL-PRF-38534 Class H, Class E and DSCC SMD Test
Program
Class H:
Avago Technologies’ s Hi-Rel Optocouplers are in compli-
ance with MIL-PRF-38534 Class H. Class H devices are also
in compliance with DSCC drawing 5962-93140.
Testing consists of 100% screening and quality confor-
mance inspection to MIL-PRF-38534.
Class E:
Class E devices are in compliance with DSCC drawing
5962-9314001Exx. Avago Technologies has de ned the
Class E device on this drawing to be based on the Class K
requirements of MIL-PRF-38534 with exceptions. The ex-
ceptions are as follows:
1. Nondestructive Bond Pull, Test method 2023 of MIL-
STD-883 in device screening is not required.
2. Particle Impact Noise Detection (PIND), Test method
2020 of MIL-STD-883 in device screening and group C
testing is not required.
3. Die Shear Strength, Test method 2019 of MIL-STD-883
in group B testing is not required.
4. Internal Water Vapor Content, Test method 1018 of MIL-
STD-883 in group C testing is not required.
5. Scanning Electron Microscope (SEM) inspections, Test
method 2018 of MIL-STD-883 in element evaluation is
not required.