Linear Technology LTC6993-4: 100ms, Falling Eged, Retriggerable, High Output, One Shot DC1562A-J DC1562A-J Fiche De Données
Codes de produits
DC1562A-J
LTC6993-1/LTC6993-2
LTC6993-3/LTC6993-4
14
69931234fb
OPERATION
Monostable Multivibrator (One Shot)
The LTC6993 is a monostable multivibrator. A trigger
The LTC6993 is a monostable multivibrator. A trigger
signal on the TRIG input will force the output to the active
(unstable) state for a programmable duration. This type
of circuit is commonly referred to as a one-shot pulse
generator.
Figures 3 details the basic operation. A rising edge on
Figures 3 details the basic operation. A rising edge on
the TRIG pin initiates the output pulse. The pulse width
(t
OUT
) is determined by the N
DIV
setting and by the resis-
tor (R
SET
) connected to the SET pin. Subsequent rising
edges on TRIG have no affect until the completion of the
one shot and for a short rearming time (t
ARM
) thereafter.
To ensure proper operation, positive and negative TRIG
pulses should be at least t
WIDTH
wide.
The LTC6993-2 and LTC6993-4 allow the output pulse to
be “retriggered”. As shown in Figure 4, the output pulse
will stay high until t
OUT
after the last rising-edge on TRIG.
Successive trigger signals can extend the pulse width in-
definitely. Consecutive trigger signals must be separated
by t
RETRIG
to be recognized.
Negative Trigger Versions
In addition to the retrigger option, the LTC6993 family also
In addition to the retrigger option, the LTC6993 family also
includes negative input (falling-edge) versions. These four
combinations are detailed in Table 2.
Table 2. Retrigger and Input Polarity Options
DEVICE
INPUT POLARITY
RETRIGGER
LTC6993-1
Rising-Edge
No
LTC6993-2
Rising-Edge
Yes
LTC6993-3
Falling-Edge
No
LTC6993-4
Falling-Edge
Yes
Output Polarity (POL Bit)
Each variety of LTC6993 also offers the ability to invert
Each variety of LTC6993 also offers the ability to invert
the output, producing negative pulses. This option is
programmed, along with N
DIV
, by the choice of DIVCODE.
(The previous section describes how to program DIVCODE
using the DIV pin).
Figure 3. Non-Retriggering Timing Diagram (LTC6993-1, POL = 0)
Figure 4. Retriggering Timing Diagram (LTC6993-2, POL = 0)
t
PD
t
WIDTH
t
RETRIG
TRIG
OUT
t
OUT
t
PD
t
PD
t
PD
t
OUT
t
OUT
69931234 F04
t
PD
TRIG
OUT
t
PD
t
ARM
t
WIDTH
t
OUT
t
OUT
t
OUT
69931234 F03