SM3 Datasheet, PDF (31/36 Pages) Connor-Winfield Corporation – ULTRA MINIATURE STRATUM 3 MODULE

Application Notes continued
Required External Components
1. Place series resistors (33 ohms) on all reference inputs (Pins 4 - 7).
2. Place series resistors (33 ohms) on SPI_IN and SPI_CLK inputs (Pins 21, 22).
3. Place one .01uF and one 47-100uF capacitor at the input power pin (Pin 23).
PCB Layout Recommendations
1. Orient module so airflow is parallel along the header strips (pins).
2. Place de-coupling and/or filter components as close to module pins as possible.
3. Do not place any components directly beneath the module on the topside of the host PCB.
4. Ensure that only clean and well-regulated power is supplied to the module.
5. Isolate power and ground inputs to the module from noisy sources.
6. Provide power and ground connections through a 0.050" wide trace (minimum) using 1-oz. Cu or equivalent copper feature (i.e.
internal plane, copper area fill, etc.).
7. Keep module signals away from sensitive or noisy analog and digital circuitry.
8. Avoid split ground planes as high-frequency return currents may be affected.
9. Allow extra spacing between traces of high-frequency inputs and outputs.
10.Keep all traces as short as possible - avoid meandering trace paths.
11.Avoid routing signals directly beneath the module on the topside of the host PCB.
12.If possible, provide a copper area directly beneath the module on the topside of the host PCB. Connect this copper area to
ground.
13.It is recommended that the connections of the JTAG, VPP and VPN pins be routed to pads, preferably in a SIL pattern as shown
in Figure 12 below. It is recommended to use 0.1” center to center spacing.
1
8
Figure 12
Optional Socket Mounting Recommendations
Mating sockets may be used if permanent installation of the SM3 module is not desired. Two possible sources for these sockets
include:
1.
Samtec, "Low Profile Socket Strips", SL Series, PN SL-114-G-19. (http://www.samtec.com/)
2.
Mill-Max, "Single-In-Line Sockets", 315 Series, PN 315-xx-114-41-001. (http://www.mill-max.com/)
The SM3 requires two 14-pin sockets. The optional dual footprint configuration shown in Figure 13 requires one 14-pin and two
16-pin sockets.
Data Sheet #: TM052 Page 31 of 36 Rev: 03 Date: 11/07/08
© Copyright 2008 The Connor-Winfield Corp. All Rights Reserved Specifications subject to change without notice