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FEATURES
All-silicon pulse width generator
Five programmable widths
Equal and unequal increments available
Pulse widths from 5 ns to 500 ns
Widths are stable and precise
Rising edge-triggered
Inverted and non-inverted outputs
Width tolerance ±5% or ±2 ns, whichever is
greater
Economical
Auto-insertable, low profile
Low-power CMOS
TTL/CMOS-compatible
Vapor phase, IR and wave solderable
Custom widths available
Fast turn prototypes
Extended temperature range available
PIN ASSIGNMENT
PIN DESCRIPTION
IN – Trigger Input
P0-P2 – Programming Pins
GND – Ground
OUT – Pulse Output
OUT – Inverted Pulse Output
VCC – +5V
DESCRIPTION
The DS1040 Pulse Generator is a user-programmable one-shot with a choice of five precise pulse widths.
Maximum widths range from 50 ns to 500 ns; increments range from 2.5 ns to 100 ns. For maximum
flexibility in applications such as magneto-optical read/write disk laser power control, varieties are
offered with equal and unequal increments. The DS1040 is offered in standard 8-pin DIPs and 8-pin
mini-SOICs. Low cost and superior reliability over hybrid technology are achieved by the combination
of a 100% CMOS silicon design and industry standard packaging. The DS1040 series of pulse generators
provide a nominal width accuracy of ±5% or ±2 ns, whichever is greater. In response to the rising edge
of the input (trigger) pulse, the DS1040 produces an output pulse with a width determined by the logic
states of the three parallel programming pins. For convenience, both inverting and non-inverting outputs
are supplied. The intrinsic delay between the trigger pulse and the output pulse is no more than 10 ns.
Each output is capable of driving up to five 74LS loads.
Dallas Semiconductor can customize standard products to meet special needs. For special request and
rapid delivery, call (972) 371–4348.
DS1040
Programmable One-Shot
Pulse Generato
www.dalsemi.com
DS1040Z 8-Pin SOIC (150-mil)
See Mech. Drawings Section
IN
OUT
OUT
GND
V
CC
P2
P0
P1
1
DS1040M 8-Pin DIP (300-mil)
See Mech. Drawings Section
V
CC
P2
P0
P1
IN
OUT
OUT
GND
1

DS1040
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LOGIC DIAGRAM Figure 1
PULSE WIDTH VS. PROGRAMMED VALUE Table 1
PROGRAMMING
PINS
MAX
WIDTH
MIN
WIDTH
MAX
WIDTH
MAX
WIDTH
MAX
WIDTH
MSB P2 0 0 0 0 1 1 1 1
P1 0 0 1 1 0 0 1 1
LSB P0 0 1 0 1 0 1 0 1
PART
NUMBER
DS1040-75 75 15 30 45 60 75 75 75
DS1040-100 100 20 40 60 80 100 100 100
DS1040-150 150 30 60 90 120 150 150 150
DS1040-200 200 40 80 120 160 200 200 200
DS1040-250 250 50 100 150 200 250 250 250
DS1040-500 500 100 200 300 400 500 500 500
DS1040-B50 50 30 35 40 45 50 50 50
DS1040-D60 60 20 30 40 50 60 60 60
DS1040-A15 15 5 7.5 10 12.5 15 15 15
DS1040-A20 20 10 12.5 15 17.5 20 20 20
DS1040-A32 32.5 22.5 25 27.5 30 32.5 32.5 32.5
DS1040-B40 40 20 25 30 35 40 40 40
DS1040-D70 70 30 40 50 60 70 70 70
All times in nanoseconds.
Custom pulse widths available.

DS1040
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ABSOLUTE MAXIMUM RATINGS*
Voltage on any Pin Relative to Ground -1.0V to +7.0V
Operating Temperature 0°C to 70°C
Storage Temperature -55°C to +125°C
Soldering Temperature 260°C for 10 seconds
Short Circuit Output Current 50 mA for 1 second
* This is a stress rating only and functional operation of the device at these or any other conditions above
those indicated in the operation sections of this specification is not implied. Exposure to absolute
maximum rating conditions for extended periods of time may affect reliability.
DC ELECTRICAL CHARACTERISTICS (0°C to 70°C; VCC = 5.0V ± 5%)
PARAMETER SYMBOL TEST MIN TYP MAX UNITS NOTES
Supply Voltage V
CC
4.75 5.00 5.25 V 1
High Level Input
Voltage
V
IH
2.2
V
CC
+ 0.5
V1
Low Level Input
Voltage
V
IL
-0.5 0.8 V 1
Input Leakage
Current
I
I
0.0 ≤ VI ≤V
CC
-1.0 1.0 mA
Active Current I
CC
VCC = Max;
Period = Min
35 75 mA 2, 6
High Level Output
Current
I
OH
VCC = Min
VOH = 4
-1 mA
Low Level Output
Current
I
OL
VCC = Min
VOL = 0.5
8mA
AC ELEC TRICAL CHARACTERI STICS (TA = 25°C; VCC = 5.0V ± 5%)
PARAMETER SYMBOL MIN TYP MAX UNITS NOTES
Programming Setup t
PS
5ns
Programming Hold t
PH
0ns
Input Pulse Width at Logic 1 t
WIH
5ns
Input Pulse Width at Logic 0 t
WIL
5ns
Intrinsic Delay t
D
0 5 10 ns
Output Pulse Width t
WO
Table 1 ns 3, 4, 5, 7
Power-up Time t
PU
100 ms
Period Period tWO + 50 ns
CAPACITANCE (TA = 25°C)
PARAMETER SYMBOL MIN TYP MAX UNITS NOTES
Input Capacitance C
IN
510pF

DS1040
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NOTES:
1. All voltages are referenced to ground.
2. Measured with outputs open, minimum period.
3. VCC = 5V @ 25°C. Width accurate to within ±2 ns or 5%.
4. Temperature variations between 0°C and 70°C may increase or decrease width by an additional ±1 ns
or ±3%, whichever is greater.
5. For DS1040 pulse generators with maximum widths less than 50 ns, temperature variations between
0°C and 70°C may increase or decrease width by ±1 ns or ±9%, whichever is greater.
6. I
CC
is a function of frequency and maximum width. Only a pulse generator operating with 40 ns
period and VCC =5.25V will have an ICC =75 mA. For example, a -100 will never exceed 30 mA, etc.
7. See “Test Conditions” sections at the end of this data sheet.
TIMING DIAGRAM Figure 2

DS1040
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POWER-UP TIMING DIAGRAM Figure 3
TEST CIRCUIT Figure 4
TERMINOLOGY
Period: The time elapsed between the leading edge of the first trigger pulse and the leading edge of the
following trigger pulse.
t
WIH , WIL , WO
(Pulse Width): The elapsed time on the pulse between the 1.5V point on the leading edge
and the 1.5V point on the trailing edge, or the 1.5V point on the trailing edge and the 1.5V point on the
leading edge.

DS1040
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t
RISE
(Input Rise Time): The elapsed time between the 20% and the 80% point on the leading edge of
the input pulse.
t
FALL
(Input Fall Time): The elapsed time between the 80% and the 20% point on the trailing edge of
the input pulse.
tD (Intrinsic Delay): The elapsed time between the 1.5 point on the leading edge of the input trigger
pulse and the 1.5V point on the leading edge of output pulse.
t
PU
(Power-up Time): After V
CC
is valid, the time required before timing specifications is within
tolerance.
TEST SETUP DESCRIPTION
Figure 4 illustrates the hardware configuration used for measuring the timing parameters on the DS1040.
The input waveform is produced by a precision pulse generator under software control. The intrinsic
delay is measured by a time interval counter (20 ps resolution) connected between the input and each
output. Outputs are selected and connected to the counter by a VHF switch control unit. Width
measurements are made by directing both the start and stop functions of the counter to the same output.
All measurements are fully automated, with each instrument controlled by a central computer over an
IEEE 488 bus.
TEST CONDITIONS
Input:
Ambient Temperature: 25°C + 3°C
Supply Voltage (VCC): 5.0V + 0.1V
Input Pulse: High = 3.0V + 0.1V
Low = 0.0V + 0.1
Source Impedance: 50 ohm max.
Rise and Fall Time: 3.0 ns max. (measured
between 0.6V and 2.4)
Pulse Width: 500 ns (1 µs for -500)
Period: 1 µs (2 µs for -500)
Output:
The output is loaded with a 74F04. Delay is measured at the 1.5V level on the rising and falling edge.
Note:
Above conditions are for test only and do not restrict the operation of the device under other data sheet
conditions.