
3D7428
MONOLITHIC 8-BIT 
PROGRAMMABLE DELAY LINE 
(SERIES 3D7428 – LOW NOISE)
FEATURES 
 
All-silicon, low-power CMOS technology 
 
TTL/CMOS compatible inputs and outputs 
 
Vapor phase, IR and wave solderable 
 
Auto-insertable (DIP pkg.) 
 
Leading- and trailing-edge accuracy 
 
Programmable via serial or parallel interface 
 
Increment range:
 0.25 through 20.0ns 
 
Delay tolerance:
 0.5% (See Table 1) 
 
Supply current:
 3mA typical 
 
Temperature stability:
±
1.5% max (-40C to 85C) 
 
 Vdd stability:
±
0.5% max (4.75V to 5.25V)
FUNCTIONAL DESCRIPTION 
The 3D7428 device is a versatile 8-bit programmable monolithic delay 
line. The input (IN) is reproduced at the output (OUT) without inversion, 
shifted in time as per the user selection. Delay values, programmed 
either via the serial or parallel interface, can be varied over 255 equal 
steps according to the formula: 
T
i,nom
 = T
inh
 + i * T
inc
where i is the programmed address, T
inc
 is the delay increment (equal 
to the device dash number), and T
inh
 is the inherent (address zero) 
delay. The device features both rising- and falling-edge accuracy. 
The all-CMOS 3D7428 integrated circuit has been designed as a reliable, economic alternative to hybrid 
TTL programmable delay lines. It is offered in a standard 16-pin auto-insertable DIP and a surface mount 
16-pin SOL. An 8-pin SOIC package is available for applications where the parallel interface is not needed. 
TABLE 1:  PART NUMBER SPECIFICATIONS 
PART 
DELAYS AND TOLERANCES 
NUMBER 
Inherent 
Delay (ns) 
Range (ns) 
Step (ns) 
Frequency 
3D7428-0.25 
10.5 
±
 2.0 
63.75 
±
 0.4 
0.25 
±
 0.12 
6.25 MHz 
3D7428-0.5 
10.5 
±
 2.0 
127.5 
±
 0.5 
0.50 
±
 0.25 
3.12 MHz 
3D7428-1 
10.5 
±
 2.0 
255.0 
±
 1.0 
1.00 
±
 0.50 
1.56 MHz 
3D7428-1.5 
10.5 
±
 2.0 
382.5 
±
 1.5 
1.50 
±
 0.75 
1.04 MHz 
3D7428-2 
10.5 
±
 2.0 
510.0 
±
2.00 
±
 1.00 
781 KHz 
3D7428-2.5 
10.5 
±
 2.5 
637.5 
±
 2.5 
2.50 
±
 1.25 
625 KHz 
3D7428-4 
13.0 
±
 4.0 
1020 
±
 3.2 
4.00 
±
 2.00 
390 KHz 
3D7428-5 
15.0 
±
 5.0 
1275 
±
 4.0 
5.00 
±
 2.50 
312 KHz 
3D7428-7.5 
20.0 
±
 7.5 
1912.5 
±
 6.0 
7.50 
±
 3.75 
208 KHz 
3D7428-10 
23.5 
±
 10 
2550 
±
 8.0 
10.0 
±
 5.00 
156 KHz 
3D7428-15 
33.0 
±
 15 
3825 
±
 12 
15.0 
±
 9.00 
104 KHz 
3D7428-20 
42.0 
±
 20 
5100 
±
 16 
20.0 
±
 12.0 
NOTES: Any delay increment between 0.25 and 20 ns not shown is also available as standard. 
See application notes section for more details 
PACKAGES 
data
delay
devices,
  inc.
3
PIN DESCRIPTIONS
IN 
Signal Input 
OUT 
Signal Output 
MD 
Mode Select 
AE 
Address Enable 
P0-P7 Parallel Data Input 
SC 
Serial Clock 
SI 
Serial Data Input 
SO 
Serial Data Output 
VDD 
+5 Volts 
GND 
Ground  
1
2
3
4
8
7
6
5
IN
SO
AE
GND
VDD
OUT
SC 
SI 
3D7428Z-xx SOIC
14
13
12
11
10
3
4
5
6
7
8
SO/P0
MD 
P7 
P6 
SC 
P5 
SI
16
15
9
1
2
IN
AE
P1
P2
P3
P4
GND
VDD 
OUT 
3D7428-xx DIP 
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9
IN 
AE 
SO/P0 
P1 
P2 
P3 
P4 
GND 
VDD
OUT
MD 
P7 
P6 
SC 
P5 
SI 
3D7428S-xx SOL 
here.