3D7424
MONOLITHIC QUAD 4-BIT
PROGRAMMABLE DELAY LINE
(SERIES 3D7424)
FEATURES
•
•
•
•
•
•
•
•
•
•
•
Four indep’t programmable lines on a single chip
All-silicon CMOS technology
Low quiescent current (5mA typical)
Leading- and trailing-edge accuracy
Vapor phase, IR and wave solderable
Increment range:
0.75ns through 400ns
Delay tolerance:
3% or 2ns (see Table 1)
Line-to-line matching:
1% or 1ns typical
Temperature stability:
±1.5%
typical (-40C to 85C)
Vdd stability:
±0.5%
typical (4.75V to 5.25V)
Minimum input pulse width:
10% of total delay
I1
SC
I2
I3
I4
SI
GND
1
2
3
4
5
6
7
PACKAGES
14
13
12
11
10
9
8
VDD
AL
O1
SO
O2
O3
O4
I1
SC
I2
I3
I4
SI
GND
1
2
3
4
5
6
7
14
13
12
11
10
9
8
VDD
AL
O1
SO
O2
O3
O4
DIP-14
3D7424-xx
SOIC-14
3D7424D-xx
For mechanical dimensions, click
here
.
For package marking details, click
here
.
FUNCTIONAL DESCRIPTION
The 3D7424 device is a small, versatile, quad 4-bit programmable
monolithic delay line. Delay values, programmed via the serial interface,
can be independently varied over 15 equal steps. The step size (in ns) is
determined by the device dash number. Each input is reproduced at the
corresponding output without inversion, shifted in time as per user
selection. For each line, the delay time is given by:
TD
n
= T0 + A
n
* TI
PIN DESCRIPTIONS
I1-I4
O1-O4
AL
SC
SI
SO
VDD
GND
Signal Inputs
Signal Outputs
Address Latch In
Serial Clock In
Serial Data In
Serial Data Out
5.0V
Ground
where T0 is the inherent delay, A
n
is the delay address of the n-th line
and TI is the delay increment (dash number). The desired addresses are
shifted into the device via the SC and SI inputs, and the addresses are latched using the AL input. The
serial interface can also be used to enable/disable each delay line. The 3D7424 operates at 5 volts and
has a typical T0 of 6ns. The 3D7424 is TTL/CMOS-compatible, capable of sourcing or sinking 4mA loads,
and features both rising- and falling-edge accuracy. The device is offered in a standard 14-pin auto-
insertable DIP and a space saving surface mount 14-pin SOIC.
TABLE 1: PART NUMBER SPECIFICATIONS
Part
Number
3D7424-.75
3D7424-1
3D7424-1.5
3D7424-2
3D7424-4
3D7424-5
3D7424-10
3D7424-15
3D7424-20
3D7424-40
3D7424-50
3D7424-100
3D7424-200
3D7424-400
DELAYS & TOLERANCES (NS)
Delay
Inherent
Total
Relative
Step
Delay
Delay
Tolerance
.75
±
0.19 6.0
±
2.0 17.25
±
2.0 3% or 0.50ns
1.0
±
0.25 6.0
±
2.0
21.0
±
2.0 3% or 0.50ns
1.5
±
0.38 6.0
±
2.0
28.5
±
2.0 3% or 0.50ns
2.0
±
0.50 6.0
±
2.0
36.0
±
2.0 3% or 0.75ns
4.0
±
1.00 6.0
±
2.0
66.0
±
2.0 3% or 0.75ns
5.0
±
1.25 6.0
±
2.0
81.0
±
2.5 3% or 0.75ns
10
±
2.50 6.0
±
2.0
156
±
5.0 3% or 1.25ns
15
±
3.75 6.0
±
2.0
231
±
7.5 3% or 1.88ns
20
±
5.00 6.0
±
2.0
306
±
10 3% or 2.50ns
40
±
10.0 6.0
±
2.0
606
±
20 3% or 5.00ns
50
±
10.0 6.0
±
2.0
756
±
25 3% or 6.25ns
100
±
12.5 6.0
±
2.0
1506
±
50 3% or 12.5ns
200
±
20.0 6.0
±
2.0 3006
±
100 3% or 25.0ns
400
±
40.0 6.0
±
2.0 6006
±
200 3% or 50.0ns
INPUT RESTRICTIONS
Max Frequency
Min Pulse Width
Recom’d Absolute Recom’d
Absolute
19 MHz
166 MHz
26 ns
3.0 ns
16 MHz
166 MHz
32 ns
3.0 ns
12 MHz
111 MHz
43 ns
4.5 ns
9.2 MHz
83 MHz
54 ns
6.0 ns
5.0 MHz
83 MHz
99 ns
6.0 ns
4.1 MHz
66 MHz
122 ns
7.5 ns
2.1 MHz
33 MHz
234 ns
15.0 ns
1.4 MHz
22 MHz
347 ns
22.5 ns
1.0 MHz
16 MHz
459 ns
30.0 ns
550 KHz
8.3 MHz
909 ns
60.0 ns
440 KHz
6.6 MHz
1.2 us
75.0 ns
220 KHz
3.3 MHz
2.3 us
150 ns
110 KHz
1.6 MHz
4.5 us
300 ns
55 KHz
833 KHz
9.0 us
600 ns
NOTE: Any increment between 0.75ns and 400ns not shown is also available as standard
See page 4 for details regarding input restrictions
2006
Data Delay Devices
Doc #06019
6/5/2006
DATA DELAY DEVICES, INC.
3 Mt. Prospect Ave. Clifton, NJ 07013
1
3D7424
APPLICATION NOTES
THEORY OF OPERATION
The quad 4-bit programmable 3D7424 device
architecture is comprised of four independently
operating delay lines. Each delay line produces
at its output a replica of the signal present at its
input, shifted in time. A single delay line is
comprised of a number of delay cells connected
in series. Delay selection is achieved by routing
one output in each string of cells to its respective
output pin (O1-O4). The delay of each of the four
lines can be controlled independently, via the
serial interface, as described in the next section.
The change in delay from one address setting to
the next is called the
increment,
or LSB. It is
nominally equal to the device dash number. The
minimum delay, achieved by setting the address
of a line to zero, is called the
inherent delay.
For best performance, it is essential that the
power supply pin be adequately bypassed and
filtered. In addition, the power bus should be of
as low an impedance construction as possible.
Power planes are preferred. Also, signal traces
should be kept as short as possible.
DELAY
LINE
DELAY
LINE
DELAY
LINE
DELAY
LINE
ADDR4
AL
SI
SC
ADDR3
ADDR2
ADDR1
ENABLES
PROGRAMMED DELAY INTERFACE
Figure 1 illustrates the main functional blocks of
the 3D7424 device. Since the device is a CMOS
design, all unused input pins must be returned to
well defined logic levels (VDD or GND). The
delays are adjusted by first shifting a 20-bit
programming word into the device via the SC and
SI pins, then strobing the AL signal to latch the
values. The bit sequence is shown in Table 2,
and the associated timing diagram is shown in
Figure 2. Each line has associated with it an
enable bit. Setting this bit low will force the
corresponding delay line output to a high
impedance state, while setting it high returns the
line to its normal operation. The device contains
an SO output, which can be used to cascade
multiple devices, as shown in Figure 3.
TABLE 2: BIT SEQUENCE
Bit
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
Delay
Line
4
3
2
1
1
Function
Output Enable
Output Enable
Output Enable
Output Enable
Address Bit 3
Address Bit 2
Address Bit 1
Address Bit 0
Address Bit 3
Address Bit 2
Address Bit 1
Address Bit 0
Address Bit 3
Address Bit 2
Address Bit 1
Address Bit 0
Address Bit 3
Address Bit 2
Address Bit 1
Address Bit 0
I4
O4
2
I3
O3
I2
O2
3
I1
O1
4
20-BIT LATCH
20-BIT SHIFT REGISTER
SO
Figure 1: Functional block diagram
t
LW
LATCH
(AL)
CLOCK
(SC)
SERIAL
INPUT
(SI)
SERIAL
OUTPUT
(SO)
DELAY
TIMES
t
CW
t
CW
t
CSL
t
DSC
NEW
BIT 1
t
DHC
NEW
BIT 2
NEW
BIT 20
t
PCQ
OLD
BIT 1
OLD
BIT 2
OLD
BIT 20
NEW
BIT 1
t
LDX
PREVIOUS VALUES
t
LDV
NEW
VALUES
Figure 2: Serial interface timing diagram
Doc #06019
6/5/2006
DATA DELAY DEVICES, INC.
Tel: 973-773-2299
Fax: 973-773-9672
http://www.datadelay.com
2
3D7424
APPLICATION NOTES (CONT’D)
DELAY ACCURACY
There are a number of ways of characterizing the
delay accuracy of a programmable line. The first
is the
differential nonlinearity
(DNL), also referred
to as the increment error. It is defined as the
deviation of the delay step at a given address
from its nominal value. For all dash numbers, the
DNL is within 1/4 LSB at every address (see
Table 1: Delay Step).
The
integrated nonlinearity
(INL) is determined
by first constructing the least-squares best fit
straight line through the delay-versus-address
data. The INL is then the deviation of a given
delay from this line. For all dash numbers, the
INL is within 1.0 LSB at every address.
The
relative error
is defined as follows:
e
rel
= (T
i
– T
0
) – i * T
inc
where i is the address, T
i
is the measured delay
at the i’th address, T
0
is the measured inherent
delay, and T
inc
is the nominal increment. It is very
similar to the INL, but simpler to calculate. For
most dash numbers, the relative error is less than
1/8 LSB at every address (see Table 1: Relative
Tolerance).
The
absolute error
is defined as follows:
e
abs
= T
i
– (T
inh
+ i * T
inc
)
where T
inh
is the nominal inherent delay. The
absolute error tolerance is given for addresses 0
and 15 (see Table 1: Inherent Delay, Total Delay,
respectively). At any intermediate address, the
tolerance can be found via linear interpolation of
the address 0 & address 15 tolerances.
The
matching error
is a measure of how well the
delay of the four lines track each other when they
are all programmed to the same address. The
lines are typically matched to within 1% or 1ns,
whichever is greater, for all addresses and all
dash numbers.
DELAY STABILITY
The delay of CMOS integrated circuits is strongly
dependent on power supply and temperature.
The 3D7424 utilizes novel compensation circuitry
to minimize the delay variations induced by
fluctuations in power supply and/or temperature.
With regard to stability, the delay of the 3D7424
at a given address, i, can be split into two
components: the
inherent delay
(T
0
) and the
relative delay
(T
i
– T
0
). These components exhibit
very different stability coefficients, both of which
must be considered in very critical applications.
The thermal coefficient of the relative delay is
limited to
±250
PPM/C, which is equivalent to a
variation, over the -40C to 85C operating range,
of
±1.5%
from the room-temperature delay
settings. This holds for dash numbers greater
than 1. For smaller dash numbers, the thermal
drift will be larger and will always be positive. The
thermal coefficient of the inherent delay is
nominally +15ps/C for all dash numbers.
The power supply sensitivity of the relative delay
is
±0.5%
over the 4.75V to 5.25V operating
range, with respect to the delay settings at the
nominal 5.0V power supply. This holds for all
dash numbers greater than 1. For smaller dash
numbers, the voltage sensitivity will be greater
and will always be negative. The sensitivity of the
inherent delay is nominally -1ps/mV for all dash
numbers.
SI
3D7424
AL
SO
SI
3D7424
AL
SO
SI
3D7424
AL
SO
FROM
WRITING
DEVICE
SC
SC
SC
TO
NEXT
DEVICE
Figure 3: Cascading Multiple Devices
Doc #06019
6/5/2006
DATA DELAY DEVICES, INC.
3 Mt. Prospect Ave. Clifton, NJ 07013
3
3D7424
APPLICATION NOTES (CONT’D)
INPUT SIGNAL CONSIDERATIONS
The frequency and/or pulse width (high or low) of
operation may adversely impact the specified
delay and increment accuracy of the particular
device. The reasons for the dependency of the
output delay accuracy on the input signal
characteristics are varied and complex.
Therefore, a recommended and an absolute
maximum operating input frequency and a
recommended and an absolute minimum
operating pulse width have been specified.
OPERATING FREQUENCY
The absolute maximum operating frequency
specification, tabulated in Table 1, determines
the highest frequency of the delay line input
signal that can be reproduced, shifted in time at
the device output, with acceptable duty cycle
distortion.
The recommended maximum operating
frequency specification determines the highest
frequency of the delay line input signal for which
the output delay accuracy is guaranteed.
Operation above the recommended maximum
frequency will cause the delays to shift slighty
with respect to their values at low-frequency
operation. The magnitudes of these deviations
will increase as the absolute maximum frequency
is approached. However, if the input frequency
and pulse width remain constant, the device will
exhibit the same delays from one period to the
next (ie, no appreciable jitter).
OPERATING PULSE WIDTH
The absolute minimum operating pulse width
(high or low) specification, tabulated in Table 1,
determines the smallest pulse width of the delay
line input signal that can be reproduced, shifted
in time at the device output, with acceptable
pulse width distortion.
The minimum operating pulse width (high or low)
specification determines the smallest pulse width
of the delay line input signal for which the output
delay accuracy tabulated in Table 1 is
guaranteed.
Operation below the recommended minimum
pulse width will cause the delays to shift slighty
with respect to their values at long-pulse-width
operation. The magnitudes of these deviations
will increase as the absolute minimum pulse
width is approached. However, if the input pulse
width and frequency remain constant, the device
will exhibit the same delays from one period to
the next (ie, no appreciable jitter).
PROGRAMMED DELAY UPDATE
A delay line is a memory device. It stores
information present at the input for a time equal
to the delay setting before presenting it at the
output. Each 4-bit delay line in the 3D7424 is
represented by 15 serially connected delay
elements (individually addressed by the
programming data), each capable of storing data
for a time equal to the device increment (step
time). The delay line memory property, in
conjunction with the operational requirement of
“instantaneously” connecting the delay element
addressed by the programming data to the
output, may inject spurious information onto the
output data stream. In order to ensure that
spurious outputs do not occur, it is essential that
the input signal be idle (held high or low) for a
short duration prior to updating the programmed
delay. This duration is given by the maximum
programmable delay. Satisfying this requirement
allows the delay line to “clear” itself of spurious
edges. Once the new address is loaded, the
input signal can begin to switch.
Doc #06019
6/5/2006
DATA DELAY DEVICES, INC.
Tel: 973-773-2299
Fax: 973-773-9672
http://www.datadelay.com
4
3D7424
DEVICE SPECIFICATIONS
TABLE 3: ABSOLUTE MAXIMUM RATINGS
PARAMETER
DC Supply Voltage
Input Pin Voltage
Input Pin Current
Storage Temperature
Lead Temperature
SYMBOL
V
DD
V
IN
I
IN
T
STRG
T
LEAD
MIN
-0.3
-0.3
-10
-55
MAX
7.0
V
DD
+0.3
10
150
300
UNITS
V
V
mA
C
C
NOTES
25C
10 sec
TABLE 4: DC ELECTRICAL CHARACTERISTICS
(-40C to 85C, 4.75V to 5.25V)
PARAMETER
Static Supply Current*
High Level Input Voltage
Low Level Input Voltage
High Level Input Current
Low Level Input Current
High Level Output Current
Low Level Output Current
Output Rise & Fall Time
SYMBOL
I
DD
V
IH
V
IL
I
IH
I
IL
I
OH
I
OL
T
R
& T
F
MIN
2.0
-0.1
-0.1
0.0
0.0
-8.0
7.5
2
0.8
0.1
0.1
-6.0
TYP
5.0
MAX
7.0
UNITS
mA
V
V
µA
µA
mA
mA
ns
NOTES
V
DD
= 5.25V
V
IH
= V
DD
V
IL
= 0V
V
DD
= 4.75V
V
OH
= 2.4V
V
DD
= 4.75V
V
OL
= 0.4V
C
LD
= 5 pf
6.0
*I
DD
(Dynamic) = 4 * C
LD
* V
DD
* F
where: C
LD
= Average capacitance load/line (pf)
F = Input frequency (GHz)
Input Capacitance = 10 pf typical
Output Load Capacitance (C
LD
) = 25 pf max
TABLE 5: AC ELECTRICAL CHARACTERISTICS
(-40C to 85C, 4.75V to 5.25V)
PARAMETER
Latch Width
Data Setup to Clock
Data Hold from Clock
Clock Width (High or Low)
Clock Setup to Latch
Clock to Serial Output
Latch to Delay Valid
Latch to Delay Invalid
Input Pulse Width
Input Period
Input to Output Delay
SYMBOL
T
LW
t
DSC
t
DHC
t
CW
t
CSL
t
PCQ
t
LDV
t
LDX
t
WI
Period
t
PLH
, t
PHL
MIN
10
10
1
15
20
TYP
MAX
UNITS
ns
ns
ns
ns
ns
ns
ns
ns
% of Total Delay
% of Total Delay
ns
NOTES
12
35
5
10
20
20
45
1
1
See Table 1
See Table 1
See Text
NOTES: 1 -
Refer to
PROGRAMMED DELAY UPDATE
section
Doc #06019
6/5/2006
DATA DELAY DEVICES, INC.
3 Mt. Prospect Ave. Clifton, NJ 07013
5
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