Return-Path: Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by klubnl.pl (8.14.4/8.14.4/Debian-8+deb8u2) with ESMTP id w01Fudfu023666 for ; Mon, 1 Jan 2018 16:56:42 +0100 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1eW2NJ-00043r-QY for rs_out_1@blacksheep.org; Mon, 01 Jan 2018 15:51:41 +0000 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1eW2NG-00043g-L7 for rsgb_lf_group@blacksheep.org; Mon, 01 Jan 2018 15:51:38 +0000 Received: from mout01.posteo.de ([185.67.36.65]) by relay1.thorcom.net with esmtps (TLSv1.2:ECDHE-RSA-AES256-GCM-SHA384:256) (Exim 4.89) (envelope-from ) id 1eW2NA-0007xK-WD for rsgb_lf_group@blacksheep.org; Mon, 01 Jan 2018 15:51:36 +0000 Received: from submission (posteo.de [89.146.220.130]) by mout01.posteo.de (Postfix) with ESMTPS id 29F8520E0F for ; Mon, 1 Jan 2018 16:51:31 +0100 (CET) X-DKIM-Result: Domain=posteo.de Result=Signature OK DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=posteo.de; s=2017; t=1514821892; bh=r3mQD/Wu8HEGa9oINt5DVjMNzyNfpfXIqqCvzAAs99k=; h=Date:From:To:Subject:From; b=lRjSOmJ/zuML+1dFlbUBPlvxjWTiNmI0VYkqcZQuNXJeNq63O0l1cyNF6E4PjuHzO Iq7wAjLoEzRuysFMwbL9nlYqlwgk4WxNb8vMSuQq06ZCFWu4/r5uqXtwqX0Be/1Xgy u90nxIWa/Gden5XJmHvhtKUvbYapGamJ9jIegJyG2GtDduc0VZ6cqYgS8rF0deYjJz 6WAg2ck/+N478pOZZkVgmHRj/T+8fJNFWrFIEKjFtU6hw7GYS7jeoQbz7laaTpDxIc 80lZ/Tc9/0gzMSrmfUjedeRq+4hcOLZUPBbecyJkbdacaNrUUPrVHG6lsxqgQAOCPU GwEfKPNyQ57sw== Received: from customer (localhost [127.0.0.1]) by submission (posteo.de) with ESMTPSA id 3z9MBB3qfgz9rxP for ; Mon, 1 Jan 2018 16:51:30 +0100 (CET) Message-ID: <5A4A5902.6050904@posteo.de> Date: Mon, 01 Jan 2018 16:51:30 +0100 From: DK7FC User-Agent: Mozilla/5.0 (Windows; U; Windows NT 6.1; de; rv:1.9.1.8) Gecko/20100227 Thunderbird/3.0.3 MIME-Version: 1.0 To: rsgb_lf_group@blacksheep.org References: <1245872871.20180101103858@gmail.com> <5A4A5600.4030607@posteo.de> In-Reply-To: <5A4A5600.4030607@posteo.de> X-Spam-Score: 0.0 (/) X-Spam-Report: Spam detection software, running on the system "relay1.thorcom.net", has NOT identified this incoming email as spam. The original message has been attached to this so you can view it or label similar future email. If you have any questions, see the administrator of that system for details. Content preview: PS: For LF(x2), a 6N137-L may be a better choise. But it needs a 5V supply. If you can get an IXXD614CI as a MOSFET driver, this will be a fine PA! [...] Content analysis details: (0.0 points, 5.0 required) pts rule name description ---- ---------------------- -------------------------------------------------- -0.0 T_RP_MATCHES_RCVD Envelope sender domain matches handover relay domain 0.0 HTML_MESSAGE BODY: HTML included in message 0.0 T_DKIM_INVALID DKIM-Signature header exists but is not valid X-Scan-Signature: 350b42a0642244046701ed1a68bf48aa Subject: Re: LF: Si5351A syntehsiser able to fire a FET driver chip directly?? Content-Type: multipart/alternative; boundary="------------000309060304000301000100" X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: X-Spam-Status: No, hits=0.5 required=5.0 tests=HTML_20_30,HTML_MESSAGE autolearn=no version=2.63 X-SA-Exim-Scanned: Yes Sender: owner-rsgb_lf_group@blacksheep.org Precedence: bulk Reply-To: rsgb_lf_group@blacksheep.org X-Listname: rsgb_lf_group X-SA-Exim-Rcpt-To: rs_out_1@blacksheep.org X-SA-Exim-Scanned: No; SAEximRunCond expanded to false This is a multi-part message in MIME format. --------------000309060304000301000100 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit PS: For LF(x2), a 6N137-L may be a better choise. But it needs a 5V supply. If you can get an IXXD614CI as a MOSFET driver, this will be a fine PA! 73, Stefan Am 01.01.2018 16:38, schrieb DK7FC: > Hi Chris, > > With the 2.2 V, drive an optocoupler! Like 4N28, CNY17/4 or similar. > This can be done with 2.2 V (use a resistor of a few 10 Ohm, calculate > it). It shifts the level to a 12V logic. The slightly distorted signal > will look perfect after the divide by 2 stage and will have a perfect > 50% duty cycle. Then drive a MOF-FET driver with this signal. > BTW for a class-D PA with opposite phase gate voltages i would > generally receommend to use a gate transformer! It makes sure that > there can never be a positive voltage on both gates to the same time, > since vgs1 is always -vgs2, what ever transients are doing. Then you > don't need to care about propagation delay, rise time and such stuff. > > 73, Stefan > > > Am 01.01.2018 11:38, schrieb Chris Wilson: >> >> Hello LF'ers, and a happy and healthy New Year to you all. >> >> I use my U3S QRP Labs exciter to drive a PA on 137kHz, and it works >> fine. Hans, the designer, made changes allowing a 180 degree out of >> phase pair of signals to come from the Si5351A synthesizer chip with >> the intention of this being able to drive a push pull Class D FET >> driver chip directly without a X2 signal being divided and split by a >> preceding IC, please see original and simplified circuits below. I >> tried this but it appears the circa 2.2V outputs of the Si5351A chip >> are not sufficient to drive the inputs of the IR2110 FET driver. >> >> Any ideas please? Thanks. >> >> Original PA circuit (works fine with "normal" U3S driving the 74F74 >> direct with CLK0 output): >> >> http://www.gatesgarth.com/amp.jpg >> >> >> >> Modded amp circuit (simplified in the hope of building with one less >> IC): >> >> http://www.gatesgarth.com/amp-modded.jpg >> >> >> >> IR2110FET driver specs: >> >> http://www.gatesgarth.com/IR2110.pdf >> >> >> >> 74F74 IC specs: >> >> http://www.gatesgarth.com/74F74.pdf >> >> >> U3S schematic: >> >> http://www.gatesgarth.com/u3s-schematic.jpg >> >> >> >> > --------------000309060304000301000100 Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit PS: For LF(x2), a 6N137-L may be a better choise. But it needs a 5V supply. If you can get an IXXD614CI as a MOSFET driver, this will be a fine PA!

73, Stefan

Am 01.01.2018 16:38, schrieb DK7FC:
Hi Chris,

With the 2.2 V, drive an optocoupler! Like 4N28, CNY17/4 or similar. This can be done with 2.2 V (use a resistor of a few 10 Ohm, calculate it). It shifts the level to a 12V logic. The slightly distorted signal will look perfect after the divide by 2 stage and will have a perfect 50% duty cycle. Then drive a MOF-FET driver with this signal.
BTW for a class-D PA with opposite phase gate voltages i would generally receommend to use a gate transformer! It makes sure that there can never be a positive voltage on both gates to the same time, since vgs1 is always -vgs2, what ever transients are doing. Then you don't need to care about propagation delay, rise time and such stuff.

73, Stefan


Am 01.01.2018 11:38, schrieb Chris Wilson:

Hello  LF'ers, and a happy and healthy New Year to you all.

I use my U3S QRP Labs exciter to drive a PA on 137kHz, and it works
fine. Hans, the designer, made changes allowing a 180 degree out of
phase pair of signals to come from the Si5351A synthesizer chip with
the intention of this being able to drive a push pull Class D FET
driver chip directly without a X2 signal being divided and split by a
preceding IC, please see original and simplified circuits below. I
tried this but it appears the circa 2.2V outputs of the Si5351A chip
are not sufficient to drive the inputs of the IR2110 FET driver.

Any ideas please?     Thanks.

  Original  PA  circuit (works fine with "normal" U3S driving the 74F74
  direct with CLK0 output):

http://www.gatesgarth.com/amp.jpg



Modded  amp  circuit (simplified in the hope of building with one less
IC):

http://www.gatesgarth.com/amp-modded.jpg



IR2110FET driver specs:

http://www.gatesgarth.com/IR2110.pdf



74F74 IC specs:

http://www.gatesgarth.com/74F74.pdf


U3S schematic:

http://www.gatesgarth.com/u3s-schematic.jpg




  

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