Lm4702
 User Name Stay logged in? Password
 Home Forums Rules Articles diyAudio Store Blogs Gallery Wiki Register Donations FAQ Calendar Search Today's Posts Mark Forums Read Search

 Chip Amps Amplifiers based on integrated circuits

 Please consider donating to help us continue to serve you. Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
 25th October 2005, 01:08 AM #11 Easyamp diyAudio Member     Join Date: Nov 2003 Location: United states Very exciting, I can't wait to get my sample's. I've moved away from chip amps but these seem worth the time.
 25th October 2005, 01:29 AM #12 aletheian   diyAudio Member     Join Date: Apr 2004 Location: Philly Has anyone done any "back of an envelope" math on current consumption and voltage requirements on one of these? __________________ Heghlu'meH QaQ jajvam!
 25th October 2005, 03:53 AM #13 tiltedhalo   diyAudio Member   Join Date: Sep 2005 Location: Melbourne Florida LM4702 This is the same package as the 3875,76,86 ect..... is a power darlington complimentary output pair with much higher power handling up to +- 70V to as high as 100 +- dissipation is still only 125W quiescent current is 30 ma distortion is .004 at 14RMS out, it actually is not as good overall as its conterparts just handles higher power supply voltages................
UrSv
diyAudio Member

Join Date: Jan 2002
Location: Sweden
Re: LM4702

Quote:
 Originally posted by MikeLewis From the Spec Sheet: POWER DISSIPATION AND HEAT SINKING When in “play” mode, the LM4702 draws a constant amount of current, regardless of the input signal amplitude. Consequently, the power dissipation is constant for a given supply voltage and can be computed with the equation PDMAX = Icc * (Vcc – Vee). For a quick calculation of PDMAX, approximate the current to be 25mA and multiply it by the total supply voltage (the current varies slightly from this value over the operating range). Constant power draw? This sounds like it's going to be a real hog. Is this Class A?

Quote:
 Originally posted by tiltedhalo This is the same package as the 3875,76,86 ect..... is a power darlington complimentary output pair with much higher power handling up to +- 70V to as high as 100 +- dissipation is still only 125W quiescent current is 30 ma distortion is .004 at 14RMS out, it actually is not as good overall as its conterparts just handles higher power supply voltages................
Guys do the maths...

Sure it's Class A, but it's a DRIVER not a power amplifier. To build a complete amplifier you need to add external components for the output stage and that's where the big power disspation will be. The current for the driver IC is 25 mA and the current available model in production is the A grade which means maximum +/- 75 VDC supply. This gives Pmax=(75-(-75))*0.025 W = 3.75 W of dissipation. Yes, that's less than 4 W. No need to worry...
__________________
UrSv
Those who say it can't be done should not stop those who are doing it.

 25th October 2005, 04:38 PM #15 youyoung21147   diyAudio Member   Join Date: Apr 2005 Location: Belfort Nice thing ! The point is to find the suitable power follower for this awesome chip, and have the money for the heatsink invloved Gainclones may still remain the most popular chip amps
 25th October 2005, 11:34 PM #16 metal diyAudio Member     Join Date: Jan 2004 Hi Cool stuff in deed for the power hunger guys... Who can recommend the power output transistors to be used with this chip LM4702... Thanks
elementx
diyAudio Member

Join Date: Jul 2005
Location: Cleveland OH
Quote:
 Originally posted by metal Who can recommend the power output transistors to be used with this chip LM4702... Thanks

MJ11032 from Onsemit should work fine, samples are available. I know I've had a sample request on the 4702 for over a month... it's on backorder... anyone actually play with them yet?

Quote:
 Originally posted by pinkmouse That does look very interesting. However, this looks much more fun!
I agree! I actually got that chip, but it is surface mount and incredible small! I can't handle soldering it... anyone else upto the challenge?? I'd be willing to work out some sort of trade/purchase if you could just glue the thing to a piece of cardboard and solder some leads on it!

 27th October 2005, 09:23 PM #18 wes-ninja250   diyAudio Member     Join Date: Feb 2005 Location: Inverary, ON ElementX -- can you make a PCB good enough for it? You can use solder paste and a toaster oven to actually solder it on. If that's the only component on the board, I expect you would get it right after only a few tries. http://www.seattlerobotics.org/encod...6/oven_art.htm Wes __________________ Do daemons dream of electric sleep()?
 27th October 2005, 09:40 PM #19 demogorgon   diyAudio Member     Join Date: Jul 2004 Location: Behind you. ***** ********* ******, this is awsome.. I have got to get myself some o'these.. how's nationals sample program these days? just as tight as before i presume?
 27th October 2005, 10:15 PM #20 RCBandwidth   diyAudio Member     Join Date: May 2004 Location: New York and PA Funlight For ElementX: I have successfully soldered the LM4970 device and tried it out with a picmicro,it's an interesting device if you are interested in adding some "Bling" to your next project... BTW: I have a stereo microscope that I used while soldering....Those little buggers look like 18 wheelers under the scope!! Regards Bob C.

 Posting Rules You may not post new threads You may not post replies You may not post attachments You may not edit your posts BB code is On Smilies are On [IMG] code is On HTML code is Off Forum Rules
 Forum Jump User Control Panel Private Messages Subscriptions Who's Online Search Forums Forums Home Site     Site Announcements     Forum Problems Amplifiers     Solid State     Pass Labs     Tubes / Valves     Chip Amps     Class D     Power Supplies     Headphone Systems Source & Line     Analogue Source     Analog Line Level     Digital Source     Digital Line Level     PC Based Loudspeakers     Multi-Way     Full Range     Subwoofers     Planars & Exotics Live Sound     PA Systems     Instruments and Amps Design & Build     Parts     Equipment & Tools     Construction Tips     Software Tools General Interest     Car Audio     diyAudio.com Articles     Music     Everything Else Member Areas     Introductions     The Lounge     Clubs & Events     In Memoriam The Moving Image Commercial Sector     Swap Meet     Group Buys     The diyAudio Store     Vendor Forums         Vendor's Bazaar         Sonic Craft         Apex Jr         Audio Sector         Acoustic Fun         Chipamp         DIY HiFi Supply         Elekit         Elektor         Mains Cables R Us         Parts Connexion         Planet 10 hifi         Quanghao Audio Design         Siliconray Online Electronics Store         Tubelab     Manufacturers         AKSA         Audio Poutine         Musicaltech         Aussie Amplifiers         CSS         exaDevices         Feastrex         GedLee         Head 'n' HiFi - Walter         Heatsink USA         miniDSP         SITO Audio         Twin Audio         Twisted Pear         Wild Burro Audio

 Similar Threads Thread Thread Starter Forum Replies Last Post Mike Gergen Chip Amps 120 9th August 2017 03:32 PM halo0925 Chip Amps 19 13th November 2006 05:47 AM halo0925 Solid State 0 9th November 2006 11:26 PM

 New To Site? Need Help?

All times are GMT. The time now is 03:44 AM.