IC-HC Datasheet, PDF (6/10 Pages) IC-Haus GmbH – ULTRA FAST DUAL HV-KOMPARATOR

iC-HC
ULTRA FAST DUAL HV-KOMPARATOR
preliminary
Rev A1, Page 6/10
DESCRIPTION OF FUNCTION
For noise suppression four symmetrical hysteresis set-
tings can be configured as per Table 4.
P1 P0 T1 T0
Hys./Hold
00 0 0
no Hys./Hold
00 0 1
1 µs Hold
00 1 0
10 µs Hold
00 1 1
100 µs Hold
01 0 0
±17 mV Hys.
01 0 1
±33 mV Hys.
01 1 0
±55 mV Hys.
01 1
1
±100 mV Hys.
10 X X
no Hys./Hold
1 1 R/C^∗ R/C^∗ Hold with ext. R/C
Table 4: Configuration
Alternatively a hold function can be used for noise sup-
pression: Following each falling or rising edge at the
outputs the toggling is blocked for the configured hold
time. With the hold time elapsed the output will follow
the input signal instantly. Table 4 shows three pre-set
hold times. The hold function has the advantage over
the hysteresis, that it does not shift the input switch-
ing threshold. With the aid of the hold function even
extreme interferences like e.g. "bouncing" can be com-
pletely blanked. Figure 3 shows a respective example
of a zero-crossing detector.
Three hold times are pre-configured and can be cho-
sen according to Table 4 without external circuitry. For
different hold times external R/C networks can be used
at T0 and T1 (P0 and P1 = hi)). Both hold timers work
independently, so individual hold times can be chosen.
VI(x)diff
time
VO(x)
time
Figure 1: Switching characteristic without Hystere-
sis/Hold
VO(x)hys
time
VI(x)diff
+- _Vhys
time
VO(x)hold
thold
thold
thold
thold
thold
time
Figure 2: Switching characteristic with hysteresis
resp. hold function
V I(x)diff
V O (x)
V O (x)hold
thold
thold
thold
time
hysteresis too small,
no hold function
time
with hold function
thold
time
Figure 3: Blanking of noise using the hold function
∗ _{external R/C network}