DS1021
Programmable 8-Bit
Silicon Delay Line
www.dalsemi.com
FEATURES
All-silicon time delay
Models with 0.25 ns and 0.5 ns steps
Programmable using 3-wire serial port or 8-
bit parallel port
Leading and trailing edge accuracy
Economical
Auto-insertable, low profile, 16-pin SOIC
package
Low-power CMOS
TTL/CMOS-compatible
Vapor phase, IR and wave solderable
PIN ASSIGNMENT
IN
E
Q/PO
P1
P2
P3
P4
GND
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9
V
CC
OUT
S
P7
P6
C
P5
D
DS1021S 16-Pin SOIC (300-mil)
See Mech. Drawings Section
PIN DESCRIPTION
IN
P0-P7
GND
OUT
V
CC
S
E
C
Q
D
- Delay Input
- Parallel Program Pins
- Ground
- Delay Output
- +5 Volts
- Mode Select
- Enable
- Serial Port Clock
- Serial Data Output
- Serial Data Input
DESCRIPTION
The DS1021 Programmable 8-Bit Silicon Delay Line consists of an 8-bit, user-programmable CMOS
silicon integrated circuit. Delay values, programmed using either the 3-wire serial port or the 8-bit
parallel port, can be varied over 256 equal steps. The faster model (-25) offers a maximum delay of 73.75
ns with an incremental delay of 0.25 ns, while the slower model (-50) has a maximum delay of 137.5 ns
with an incremental delay of 0.5 ns. Both models have an inherent (step zero) delay of 10 ns. After the
user-determined delay, the input logic state is reproduced at the output without inversion. The DS1021 is
TTL- and CMOS-compatible, capable of driving 10 74LS-type loads, and features both rising and falling
edge accuracy.
The all-CMOS DS1021 integrated circuit has been designed as a reliable, economic alternative to hybrid
programmable delay lines. It is offered in a space-saving surface mount 16-pin SOIC.
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