MIL-PRF-38534 Class H,
Class K, and DESC SMD
Test Program
Hewlett-Packard’s Hi-Rel Opto-
couplers are in compliance with
MIL-PRF-38534 Classes H and K.
Class H devices are also in
Data Rate and Pulse-
Width Distortion
Definitions
Propagation delay is a figure of
merit which describes the finite
amount of time required for a
system to translate information
from input to output when
When tPLH and tPHL differ in
value, pulse width distortion
results. Pulse width distortion is
defined as |tPHL - tPLH| and
determines the maximum data
rate capability of a distortion-
limited system. Maximum pulse
width distortion on the order of
25-35% is typically used when
specifying the maximum data rate
capabilities of systems. The exact
figure depends on the particular
application (RS-232, PCM, T-1,
etc.).
compliance with DESC drawings
5962-89570, and 5962-89571.
shifting logic levels. Propagation
delay from low to high (tPLH
)
Testing consists of 100% screen-
ing and quality conformance
inspection to MIL-PRF-38534.
specifies the amount of time
required for a system’s output to
change from a Logic 0 to a Logic
1, when given a stimulus at the
input. Propagation delay from
high to low (tPHL) specifies the
amount of time required for a
system’s output to change from a
Logic 1 to a Logic 0, when given
a stimulus at the input (see
Figure 5).
These high performance opto-
couplers offer the advantages of
specified propagation delay (tPLH
tPHL), and pulse width distortion
(|tPLH -t PHL|) over temperature
,
and power supply voltage ranges.
Applications
V
= +5 V
CC1
30 pF
HCPL-5400
226 Ω
274 Ω
V
= 5 V
CC2
V
CC
0.1 µF
DATA
IN
DATA
OUT
TTL
A
LSTTL
STTL
Y
HCMOS
GND 1
GND
TOTEM
POLE
GND 2
Y = A
1
OUTPUT GATE
(e.g. 54AS1000)
2
Figure 13. Recommended HCPL-5400 Interface Circuit.
1-534
HP [ HEWLETT-PACKARD ]
