MC10E1652 ON Semiconductor, MC10E1652 Datasheet - Page 4

• Manufacturer Part Number: MC10E1652
• Description: DUAL ECL OUTPUT COMPARATOR WITH LATCH
• Manufacturer: ON Semiconductor

requirement to effect the correct input-output relationship.
Note that the LEN waveform in Figure 3 shows the LEN
signal swinging around a reference labeled VBB INT ; this
waveform emphasizes the requirement that LEN follow
typical ECL 10KH logic levels because VBB INT is the
internally generated reference level, hence is nominally at
the ECL VBB level.
the voltage level beyond the threshold level (V THR ) to which
the input is driven. As an example, if the threshold level is set
on one of the comparator inputs as 80 mV and the input
a specified nominal propagation delay. However, since
propagation delay is a function of input slew rate and input
voltage overdrive the delay dispersion parameters, T DE and
T DT , are provided to allow the user to adjust for these
variables (where T DE and T DT apply to inputs with standard
ECL and TTL levels, respectively).
which incorporate varying input slew rates and input voltage
overdrive. For input parameters that adhere to these
constraints the propagation delay can be described as:
MC10E1652
VBB INT
MOTOROLA
Finally, V OD is the input voltage overdrive and represents
V THR
Under a constant set of input conditions comparators have
Figure 4 and Figure 5 define a range of input conditions
– 1.07 V
– 1.58 V
– 1.75 V
LEN
–0.9 V
Q
Q
THRESHOLD
V
RANGE
INPUT
Figure 4. ECL Dispersion Test Input Conditions
V IN
T NOM
T DE (or T DT )
SLEW RATE =
0.25 V/NS
t s
V OD
SLEW RATE = 0.75 V/NS
t PHL
Figure 3. Input/Output Timing Diagram
t h
DELAY DISPERSION
2–4
signal swing on the complementary input is from zero to 100
mV, the positive going overdrive would be 20 mV and the
negative going overdrive would be 80 mV. The result of
differing overdrive levels is that the devices have shorter
propagation delays with greater overdrive because the
threshold level is crossed sooner than the case of lower
overdrive levels. Typically, semiconductor manufactures
refer to the threshold voltage as the input offset voltage
(VOS) since the threshold voltage is the sum of the externally
supplied reference voltage and inherent device offset
voltage.
where T NOM is the nominal propagation delay. T NOM
accounts for nonuniformity introduced by temperature and
voltage variability, whereas the delay dispersion parameter
takes into consideration input slew rate and input voltage
overdrive variability. Thus a modified propagation delay can
be approximated to account for the effects of input conditions
that differ from those under which the parts where tested. For
example, an application may specify an ECL input with a slew
rate of 0.25 V/NS, an overdrive of 17 mV and a temperature
of 25 C, the delay dispersion parameter would be 100 ps.
The modified propagation delay would be
2.5 V
2.0 V
0.5 V
THRESHOLD
0 V
RANGE
INPUT
Figure 5. TTL Dispersion Test Input Conditions
t pw
t PLH(LEN)
775ps
SLEW RATE =
0.30 V/NS
100ps
ECLinPS and ECLinPS Lite
SLEW RATE = 0.75 V/NS
DL140 — Rev 4