PDU138
3-BIT PROGRAMMABLE
DELAY LINE
(SERIES PDU138)
FEATURES
•
•
•
•
•
•
•
Digitally programmable in 8 delay steps
Monotonic delay-versus-address variation
Precise and stable delays
Input & outputs fully TTL interfaced & buffered
2
10 T L fan-out capability
Fits standard 16-pin DIP socket
Auto-insertable
N/C
N/C
N/C
IN
OUT
N/C
EN/
GND
data
3
®
delay
devices,
inc.
PACKAGES
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9
VCC
N/C
N/C
N/C
N/C
A0
A1
A2
PDU138-xx
PDU138-xxM
DIP
Military DIP
FUNCTIONAL DESCRIPTION
The PDU138-series device is a 3-bit digitally programmable delay line.
The delay, TD
A
, from the input pin (IN) to the output pin (OUT) depends on
the address code (A2-A0) according to the following formula:
TD
A
= TD
0
+ T
INC
* A
PIN DESCRIPTIONS
IN
OUT
A2
A1
A0
EN/
VCC
GND
Delay Line Input
Non-inverted Output
Address Bit 2
Address Bit 1
Address Bit 0
Output Enable
+5 Volts
Ground
where A is the address code, T
INC
is the incremental delay of the device,
and TD
0
is the inherent delay of the device. The incremental delay is
specified by the dash number of the device and can range from 0.5ns
through 50ns, inclusively. The enable pin (EN/) is held LOW during normal
operation. When this signal is brought HIGH, OUT is forced into the LOW
state. The address is not latched and must remain asserted during normal operation.
SERIES SPECIFICATIONS
•
•
•
•
•
•
•
•
Total programmed delay tolerance:
5% or 1ns,
whichever is greater
Inherent delay (TD
0
):
7ns typical (OUT)
Setup time and propagation delay:
Address to input setup (T
AIS
):
12ns typ.
Disable to output delay (T
DISO
):
12ns typ.
Operating temperature:
0° to 70° C
Temperature coefficient:
100PPM/°C (excludes TD
0
)
Supply voltage V
CC
:
5VDC
±
5%
Supply current:
I
CCH
= 45ma
I
CCL
= 20ma
Minimum pulse width:
20% of total delay
DASH NUMBER SPECIFICATIONS
Part
Number
PDU138-.5
PDU138-1
PDU138-2
PDU138-5
PDU138-10
PDU138-12
PDU138-15
PDU138-20
PDU138-40
PDU138-50
Incremental Delay
Per Step (ns)
.5
±
.3
1
±
.4
2
±
.4
5
±
.6
10
±
1.0
12
±
1.2
15
±
1.3
20
±
1.5
40
±
2.0
50
±
2.5
Total Delay
Change (ns)
3.5
±
1.0
7
±
1.0
14
±
1.0
35
±
1.8
70
±
3.5
84
±
4.2
105
±
5.3
140
±
7.0
280
±
14.0
350
±
17.5
NOTE: Any dash number between .5 and 50 not
shown is also available.
©
2002 Data Delay Devices
Doc #02004
5/6/02
DATA DELAY DEVICES, INC.
3 Mt. Prospect Ave. Clifton, NJ 07013
1
PDU138
APPLICATION NOTES
ADDRESS UPDATE
The PDU138 is a memory device. As such,
special precautions must be taken when
changing the delay address in order to prevent
spurious output signals. The timing restrictions
are shown in Figure 1.
After the last signal edge to be delayed has
appeared on the OUT pin, a minimum time, T
OAX
,
is required before the address lines can change.
This time is given by the following relation:
T
OAX
= max { (A
i
- A
i-1
) * T
INC
, 0 }
where A
i-1
and A
i
are the old and new address
codes, respectively. Violation of this constraint
may, depending on the history of the input signal,
cause spurious signals to appear on the OUT pin.
The possibility of spurious signals persists until
the required T
OAX
has elapsed.
A similar situation occurs when using the EN/
signal to disable the output while IN is active. In
this case, the unit must be held in the disabled
state until the device is able to “clear” itself. This
is achieved by holding the EN/ signal high and the
IN signal low for a time given by:
T
DISH
= A
i
* T
INC
Violation of this constraint may, depending on the
history of the input signal, cause spurious signals
to appear on the OUT pin. The possibility of
spurious signals persists until the required T
DISH
has elapsed.
INPUT RESTRICTIONS
There are three types of restrictions on input
pulse width and period listed in the
AC
Characteristics
table. The
recommended
conditions are those for which the delay tolerance
specifications and monotonicity are guaranteed.
The
suggested
conditions are those for which
signals will propagate through the unit without
significant distortion. The
absolute
conditions
are those for which the unit will produce some
type of output for a given input.
When operating the unit between the
recommended and absolute conditions, the
delays may deviate from their values at low
frequency. However, these deviations will remain
constant from pulse to pulse if the input pulse
width and period remain fixed. In other words,
the delay of the unit exhibits frequency and pulse
width dependence when operated beyond the
recommended conditions. Please consult the
technical staff at Data Delay Devices if your
application has specific high-frequency
requirements.
Please note that the increment tolerances listed
represent a design goal. Although most delay
increments will fall within tolerance, they are not
guaranteed throughout the address range of the
unit. Monotonicity is, however, guaranteed over
all addresses.
A2-A0
T
AENS
EN/
T
ENIS
IN
TD
A
OUT
A
i-1
T
OAX
T
AIS
A
i
PW
IN
T
DISH
PW
OU
T
DISO
Figure 1: Timing Diagram
Doc #02004
5/6/02
DATA DELAY DEVICES, INC.
Tel: 973-773-2299
Fax: 973-773-9672
http://www.datadelay.com
2
PDU138
DEVICE SPECIFICATIONS
TABLE 1: AC CHARACTERISTICS
PARAMETER
Total Programmable Delay
Inherent Delay
Disable to Output Low Delay
Address to Enable Setup Time
Address to Input Setup Time
Enable to Input Setup Time
Output to Address Change
Disable Hold Time
Absolute
Input Period
Suggested
Recommended
Absolute
Input Pulse Width
Suggested
Recommended
SYMBOL
TD
T
TD
0
T
DISO
T
AENS
T
AIS
T
ENIS
T
OAX
T
DISH
PER
IN
PER
IN
PER
IN
PW
IN
PW
IN
PW
IN
MIN
TYP
7
7.0
12.0
UNITS
T
INC
ns
ns
ns
ns
ns
2.0
12.0
12.0
See Text
See Text
20
50
200
10
25
100
% of TD
T
% of TD
T
% of TD
T
% of TD
T
% of TD
T
% of TD
T
TABLE 2: ABSOLUTE MAXIMUM RATINGS
PARAMETER
DC Supply Voltage
Input Pin Voltage
Storage Temperature
Lead Temperature
SYMBOL
V
CC
V
IN
T
STRG
T
LEAD
MIN
-0.3
-0.3
-55
MAX
7.0
V
DD
+0.3
150
300
UNITS
V
V
C
C
NOTES
10 sec
TABLE 3: DC ELECTRICAL CHARACTERISTICS
(0C to 70C, 4.75V to 5.25V)
PARAMETER
High Level Output Voltage
Low Level Output Voltage
High Level Output Current
Low Level Output Current
High Level Input Voltage
Low Level Input Voltage
Input Clamp Voltage
Input Current at Maximum
Input Voltage
High Level Input Current
Low Level Input Current
Short-circuit Output Current
Output High Fan-out
Output Low Fan-out
SYMBOL
V
OH
V
OL
I
OH
I
OL
V
IH
V
IL
V
IK
I
IHH
I
IH
I
IL
I
OS
MIN
2.5
TYP
3.4
0.35
MAX
UNITS
V
V
mA
mA
V
V
V
mA
µA
mA
mA
Unit
Load
NOTES
V
CC
= MIN, I
OH
= MAX
V
IH
= MIN, V
IL
= MAX
V
CC
= MIN, I
OL
= MAX
V
IH
= MIN, V
IL
= MAX
0.5
-1.0
20.0
2.0
0.8
-1.2
0.1
20
-0.6
-150
25
12.5
V
CC
= MIN, I
I
= I
IK
V
CC
= MAX, V
I
= 7.0V
V
CC
= MAX, V
I
= 2.7V
V
CC
= MAX, V
I
= 0.5V
V
CC
= MAX
-60
Doc #02004
5/6/02
DATA DELAY DEVICES, INC.
3 Mt. Prospect Ave. Clifton, NJ 07013
3
Microcontroller MCU
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