LTC6993CDCB-2#TRMPBF Linear Technology, LTC6993CDCB-2#TRMPBF Datasheet - Page 15

• Manufacturer Part Number: LTC6993CDCB-2#TRMPBF
• Description: IC, TIMERBLOX, SINGLE, 5.5V, DFN6
• Manufacturer: Linear Technology

Specifications of LTC6993CDCB-2#TRMPBF

• Operating Mode: Monostable
• No. Of Timers: 1
• Clock External Input: No
• Supply Voltage Range: 2.25V To 5.5V
• Digital Ic Case Style: DFN
• No. Of Pins: 6
• Operating Temperature Range: 0°C To +70°C
• Rohs Compliant: Yes
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

APPLICATIONS INFORMATION
Basic Operation
The simplest and most accurate method to program the
LTC6993 is to use a single resistor, R
SET and GND pins. The design procedure is a four step
process.
Step 1: Select the POL Bit Setting.
The LTC6993 can generate positive or negative output
pulses, depending on the setting of the POL bit. The POL
bit is the DIVCODE MSB, so any DIVCODE ≥ 8 has POL = 1
and produces active-low pulses.
Step 2: Select LTC6993 Version.
Two input-related choices dictate the proper LTC6993 for
a given application:
Use Table 2 to select a particular variety of LTC6993.
Step 3: Select the N
As explained earlier, the voltage on the DIV pin sets the
DIVCODE which determines both the POL bit and the N
value. For a given output pulse width (t
be selected to be within the following range:
To minimize supply current, choose the lowest N
However, in some cases a higher value for N
better accuracy (see Electrical Characteristics).
Table 1 can also be used to select the appropriate N
values for the desired t
With POL already chosen, this completes the selection of
DIVCODE. Use Table 1 to select the proper resistor divider
or V
• Is TRIG a rising or falling-edge input?
• Should retriggering be allowed?
16µs
t
DIV
OUT
/V
≤N
+
ratio to apply to the DIV pin.
DIV
≤
t
1µs
OUT
DIV
OUT
Frequency Divider Value.
.
OUT
SET
DIV
, between the
), N
will provide
DIV
DIV
should
value.
DIV
(1)
DIV
Step 4: Calculate and Select R
The final step is to calculate the correct value for R
using the following equation:
Select the standard resistor value closest to the calculated
value.
Example: Design a one-shot circuit that satisfies the fol-
lowing requirements:
Step 1: Select the POL Bit Setting.
For inverted (negative) output pulse, choose POL = 1.
Step 2: Select the LTC6993 Version.
A rising-edge retriggerable input requires the LTC6993-2.
Step 3: Select the N
Choose an N
Equation (1), using t
Potential settings for N
the best choice, as it minimizes supply current by us-
ing a large R
DIVCODE = 14. Using Table 1, choose R1 = 102k and
R2 = 976k values to program DIVCODE = 14.
Step 4: Select R
Calculate the correct value for R
• t
• Negative Output Pulse
• Rising-Edge Trigger Input
• Retriggerable Input
• Minimum power consumption
6.25 ≤ N
R
R
SET
SET
OUT
=
=
= 100µs
50k
50k
1µs
1µs
DIV
LTC6993-1/LTC6993-2
LTC6993-3/LTC6993-4
SET
DIV
≤ 100
•
•
N
SET
100µs
t
resistor. POL = 1 and N
OUT
value that meets the requirements of
DIV
8
.
DIV
OUT
DIV
= 625k
Frequency Divider Value.
= 100µs:
include 8 and 64. N
SET
SET
.
using Equation (2):
DIV
= 8 requires
DIV
15
69931234f
= 8 is
SET
(2)