MSTM-S3-TR_15 Datasheet, PDF (13/16 Pages) Connor-Winfield Corporation – Stratum 3 Timing Module

MECHANICAL OUTLINE:
The mechanical outline of the MSTM-S3-TR is
shown in Figure 16. The board space required is 2” x
2”. The pins are .040” in diameter and are .150” in
length. The unit is spaced off the PCB by .030”
shoulders on the pins. Due to the height of the
device it is recommended to have heat sensitive
devices away where the air flow might not be
blocked.
PAD ARRAY AND PAD SPACING:
The pins are arranged in a dual-in-line
configuration as shown in Figure 17. There is .2”
space between the pins in-line and each line is
separated by 1.6”. See Figures 16 & 17 and Table
6.
PAD CONSTRUCTION:
The recommended pad construction is shown in
Figure 17. For the pin diameter of .040” a hole
diameter of .055” is suggested for ease of insertion
and rework. A pad diameter of .150” is also
suggested for support. This leaves a spacing of
.050” between the pads which is sufficient for most
signal lines to pass through.
SOLDER MASK:
A solder mask is recommended to cover most the
top pad to avoid excessive solder underneath the
shoulder of the pin to avoid rework damage. See
Table 6 and Figure 18.
VIA KEEP OUT AREA:
It is recommended that there be no vias or feed
throughs underneath the main body of the module
between the pins. It is suggested that the traces in
this area be kept to a minimum and protected by a
layer of solder mask. See Figure 17.
GROUND AND POWER SUPPLY LINES:
Power specifications will vary depending primarily
on the temperature range. At wider temperature
ranges starting at 0 to 70 deg. C., an ovenized
oscillator, OCXO, will be incorporated. The turn-on
current for an OCXO requires a peak current of
about .4A for about a minute. The steady state
current will the vary from 50-150 mA depending on
the temperature. It is suggested to plan for the peak
current in the power and ground traces pin 18 and
pin 5. The other four ground pins 10, 12, 14, and 16
are intended for signal grounds.
POWER SUPPLY REGULATION:
Good power supply regulation is recommended for
the MSTM-S3-TR The internal oscillators are
regulated to operate from 4.75 - 5.25 volts. Large
jumps within this range may still produce varying
degrees of wander. If the host system is subject to
large voltage jumps due to hot-swapping and the like,
it is suggested that there be some form of external
regulation such as a DC/DC converter.
SOLDERING RECOMMENDATIONS:
Due to the sensitive nature of this part, hand
soldering or wave soldering of the pins is
recommended after reflow processes.
WASHING RECOMMENDATIONS:
The MSTM-S3-TR is not in a hermetic enclosure.
It is recommended that the leads be hand cleaned
after soldering. Do not completely immerse the
module.
MODULE BAKEOUT:
Do not bakeout the MSTM-S3-TR
Data Sheet #: TM027 Page 13 of 16 Rev: P05 Date: 12 / 02 / 02
© Copyright 2001 The Connor-Winfield Corp. All Rights Reserved Specifications subject to change without notice