3D7215 Datasheet, PDF (2/4 Pages) Data Delay Devices, Inc. – MONOLITHIC 5-TAP FIXED DELAY LINE (SERIES 3D7215 - LOW NOISE)

3D7215
APPLICATION NOTES
OPERATIONAL DESCRIPTION
The 3D7215 five-tap delay line architecture is
shown in Figure 1. The delay line is composed
of a number of delay cells connected in series.
Each delay cell produces at its output a replica of
the signal present at its input, shifted in time.
The delay cells are matched and share the same
compensation signals, which minimizes tap-to-
tap delay deviations over temperature and supply
voltage variations.
INPUT SIGNAL CHARACTERISTICS
The Frequency and/or Pulse Width (high or low)
of operation may adversely impact the specified
delay 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 Maximum and an Absolute
Maximum operating input frequency and a
Recommended Minimum and an Absolute
Minimum operating pulse width have been
specified.
OPERATING FREQUENCY
The Absolute Maximum 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 Frequency
specification determines the highest frequency of
the delay line input signal for which the output
delay accuracy is guaranteed. To guarantee the
Table 1 delay accuracy for input frequencies
higher than the Recommended Maximum
Frequency, the 3D7215 must be tested at the
user operating frequency. Therefore, to facilitate
production and device identification, the part
number will include a custom reference
designator identifying the intended frequency of
operation. The programmed delay accuracy of
the device is guaranteed, therefore, only at the
user specified input frequency. Small input
frequency variation about the selected frequency
will only marginally impact the programmed delay
accuracy, if at all. Nevertheless, it is strongly
recommended that the engineering staff at
DATA DELAY DEVICES be consulted.
OPERATING PULSE WIDTH
The Absolute Minimum 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 Recommended Minimum 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.
To guarantee the Table 1 delay accuracy for
input pulse width smaller than the
Recommended Minimum Pulse Width, the
3D7215 must be tested at the user operating
IN O1 O2 O3 O4 O5
IN
O1 O2 O3 O4 O5
25% 25% 25% 25%
20% 20% 20% 20% 20%
VDD
Temp & VDD
Compensation
Temp & VDD
Compensation
Dash numbers < 8
GND
VDD
Dash numbers >= 8
Figure 1: 3D7215 Functional Diagram
Doc #01015
DATA DELAY DEVICES, INC.
11/8/01
Tel: [phone] Fax: [phone] http://www.datadelay.com
GND
2