<html><head><meta http-equiv="Content-Type" content="text/html charset=windows-1252"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;">Paul, <div><br></div><div>Oooh, like the Fairchild Inverter with the advantage of reducing the current loss and not requiring any external resisters as this is a battery operated application. I am not sure about some of the qualifiers (unbuffered and ultra high speed) but this one looks like what I want and only costs $0.55. </div><div><br></div><div>Data sheet - <a href="http://www.fairchildsemi.com/ds/NC/NC7SZU04.pdf">http://www.fairchildsemi.com/ds/NC/NC7SZU04.pdf</a></div><div><br></div><div>Thanks,</div><div><br></div><div>Chip</div><div><br></div><div><br><div><div>On Mar 21, 2014, at 1:11 PM, Paul Hinson <<a href="mailto:hinson_paul@yahoo.com">hinson_paul@yahoo.com</a>> wrote:</div><br class="Apple-interchange-newline"><blockquote type="cite"><div style="background-color: rgb(255, 255, 255); font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; font-size: 12pt;"><div><span>Charles,</span></div><div style="font-size: 16px; font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; background-color: transparent; font-style: normal;"><br><span></span></div><div style="font-size: 16px; font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; background-color: transparent; font-style: normal;"><span>The IC you showed has a PNP, NPN pair and the resistors are mainly for limiting base current, which would help prevent it from going into deep saturation when using it as a switch...you'd still need to include an external resistor to pull up the collector. <br></span></div><div style="font-size: 16px; font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; background-color: transparent; font-style: normal;"><span><br></span></div><div style="font-size: 16px; font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; background-color: transparent; font-style: normal;"><span>If you want to stick with bipolar inverter, you can use individual NPN devices: </span></div><div style="font-size: 16px; font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; background-color: transparent; font-style: normal;"><span><a href="http://rohmfs.rohm.com/en/products/databook/datasheet/discrete/transistor/digital/dtc043zeb.pdf">http://rohmfs.rohm.com/en/products/databook/datasheet/discrete/transistor/digital/dtc043zeb.pdf</a></span></div><div style="font-size: 16px; font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; background-color: transparent; font-style: normal;"><br><span></span></div><div style="font-size: 16px; font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; background-color: transparent; font-style: normal;"><span>Or just use a CMOS inverter which is simple and uses near zero current (the NPN inverter style burns DC current at input and output):</span></div><div style="font-size: 16px; font-family: HelveticaNeue, 'Helvetica Neue', Helvetica, Arial, 'Lucida Grande', sans-serif; background-color: transparent; font-style: normal;"><span><a href="http://www.fairchildsemi.com/ds/NC/NC7SZ04.pdf">http://www.fairchildsemi.com/ds/NC/NC7SZ04.pdf</a></span></div><div style="display: block;" class="yahoo_quoted"> <br> <br> <div style="font-family: HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif; font-size: 12pt;"> <div style="font-family: HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif; font-size: 12pt;"> <div dir="ltr"> <font face="Arial" size="2"> On Friday, March 21, 2014 12:39 PM, Charles McClelland
<<a href="mailto:chip@mcclellands.org">chip@mcclellands.org</a>> wrote:<br> </font> </div> <div class="y_msg_container"><div id="yiv9397201466">To all, <div><br></div><div>OK, so I knew I needed to give surface mount board design a try eventually, so, I am redesigning my trail traffic counter board using surface mount components. My hope this that by buying the components instead of the breakout boards from Sparkfun, I can save money and make the board more reliable. </div><div><br></div><div>Everything is was going smoothly until I got to the part where I needed to invert the interrupt out of the accelerometer. Thanks to this group’s input, I had implemented the inverter circuit on my through hold board using the 2N2222 NPN transistor and the following circuit:</div><div><br></div><div><span><PastedGraphic-1.tiff></span></div><div><br></div><div>The problem
(opportunity?) is that there is no surface mount 2N2222 transistor. I looked on line and found this cool chip from Sparkfun: <a rel="nofollow" target="_blank" href="https://www.sparkfun.com/products/588">https://www.sparkfun.com/products/588</a></div><div><br></div><div>The cool part is that it is small, cheap and looks like it includes the resistors. The bad part is that there is no application notes with the data sheet and the resistor network is different than the circuit above. I took a guess but wanted to know if any of you could tell me if I got this right. Is this an equivalent circuit to the 2N2222 circuit above?</div><div><br></div><div><span><PastedGraphic-2.tiff></span></div><div>Or, perhaps there is a better way to invert a signal in this cool new world of surface mount
components?</div><div><br></div><div><br></div><div>Thank you all again for your help!</div><div><br></div><div><br></div></div><br>_______________________________________________<br>Triangle, NC Embedded Computing mailing list<br><a ymailto="mailto:TriEmbed@triembed.org" href="mailto:TriEmbed@triembed.org">TriEmbed@triembed.org</a><br><a href="http://mail.triembed.org/mailman/listinfo/triembed_triembed.org" target="_blank">http://mail.triembed.org/mailman/listinfo/triembed_triembed.org</a><br>TriEmbed web site: <a href="http://triembed.org/" target="_blank">http://TriEmbed.org</a><br><br><br></div> </div> </div> </div> </div></blockquote></div><br></div></body></html>