Datasheet

LTC6994-1/LTC6994-2
13
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operaTion
Figure 3. Rising-Edge Delayed Timing Diagram (LTC6994-1, POL = 0)
Figure 4. Falling-Edge Delayed Timing Diagram (LTC6994-1, POL = 1)
Edge-Controlled Delay
The LTC6994 is a programmable delay or pulse qualifier.
It can perform noise filtering, which distinguishes it from
a delay line (which simply delays all input transitions).
When the voltage on the LTC6994 input pin (IN) transitions
low or high, the LTC6994 can delay the corresponding
output transition by any time from 1µs to 33.6 seconds.
LTC6994-1 Functionality
Figures 3 details the basic operation of the LTC6994-1 when
configured to delay rising edge transitions (POL = 0). A
rising edge on the IN pin initiates the timing. OUT remains
low for the duration of t
DELAY
. If IN stays high then OUT
will transition high after this time. If the input doesn’t
remain high long enough for OUT to transition high then
the timing will restart on each successive rising edge. In
this way, the LTC6994-1 can serve as a pulse qualifier,
filtering out noisy or short signals.
On a falling edge at the input, the output will follow im-
mediately (after a short propagation delay t
PD
).Note that
the output pulse width may be extremely short if IN falls
immediately after OUT rises.
Figure
4 details the operation of the LTC6994-1 when
configured to delay falling edges (POL = 1).
IN
OUT
t
DELAY
t
PD
t
PD
t
DELAY
t
DELAY
t
PD
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t
WIDTH
t
PD
t
PD
t
PD
IN
OUT
t
DELAY
t
PD
t
DELAY
t
PD
t
PD
t
PD
t
PD
t
PD
t
WIDTH
t
DELAY
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