UK Vintage Radio Repair and Restoration Powered By Google Custom Search Vintage Radio and TV Service Data

Go Back   UK Vintage Radio Repair and Restoration Discussion Forum > General Vintage Technology > Components and Circuits

Notices

Components and Circuits For discussions about component types, alternatives and availability, circuit configurations and modifications etc. Discussions here should be of a general nature and not about specific sets.

Closed Thread
 
Thread Tools
Old 13th Apr 2019, 3:20 pm   #1
60 oldjohn
Dekatron
 
Join Date: Dec 2004
Location: East Yorkshire, UK.
Posts: 3,957
Default SMD Voltage Regulator

I need three SMD voltage regulators 3v - 3.3v output 30ma min output, 20v min input. Anyone know what device number I need ?


John.
60 oldjohn is offline  
Old 13th Apr 2019, 3:24 pm   #2
paulsherwin
Moderator
 
paulsherwin's Avatar
 
Join Date: Jun 2003
Location: Oxford, UK
Posts: 27,783
Default Re: SMD Voltage Regulator

https://www.mouser.co.uk/Semiconduct...z0shyuZ1z0wd7g
paulsherwin is offline  
Old 13th Apr 2019, 3:55 pm   #3
MrBungle
Dekatron
 
MrBungle's Avatar
 
Join Date: Jun 2016
Location: London, UK.
Posts: 3,687
Default Re: SMD Voltage Regulator

Holtek 7550 are my go to. They have 24V max input. Don’t forget bypassing heavily according to the data sheet or they turn into oscillators.

LCSC sell cheap clone ones as well for virtually nothing.
MrBungle is offline  
Old 13th Apr 2019, 4:39 pm   #4
60 oldjohn
Dekatron
 
Join Date: Dec 2004
Location: East Yorkshire, UK.
Posts: 3,957
Default Re: SMD Voltage Regulator

Are there any 7550 devices that output 3-3.3v to keep component count down?
60 oldjohn is offline  
Old 13th Apr 2019, 8:24 pm   #5
MrBungle
Dekatron
 
MrBungle's Avatar
 
Join Date: Jun 2016
Location: London, UK.
Posts: 3,687
Default Re: SMD Voltage Regulator

Yes they do fixed 3.3V version: HT7533-1
MrBungle is offline  
Old 13th Apr 2019, 8:28 pm   #6
Herald1360
Dekatron
 
Herald1360's Avatar
 
Join Date: Feb 2007
Location: Leominster, Herefordshire, UK.
Posts: 16,526
Default Re: SMD Voltage Regulator

If you're inputting 20+ V and outputting 3(.3)V, remember to allow for the dissipation if the load is more than a few mA!
__________________
....__________
....|____||__|__\_____
.=.| _---\__|__|_---_|.
.........O..Chris....O
Herald1360 is offline  
Old 13th Apr 2019, 8:46 pm   #7
MrBungle
Dekatron
 
MrBungle's Avatar
 
Join Date: Jun 2016
Location: London, UK.
Posts: 3,687
Default Re: SMD Voltage Regulator

Good point. Based on facts here, over half a watt will need to be shifted. 7550 ruled out.
MrBungle is offline  
Old 13th Apr 2019, 10:24 pm   #8
60 oldjohn
Dekatron
 
Join Date: Dec 2004
Location: East Yorkshire, UK.
Posts: 3,957
Default Re: SMD Voltage Regulator

Exact values 14v (12v Car) to 3.3v @ 22ma. Original posting allowed a little head room. There are 12v max input versions of regulators that I would not expect to last very long in this application.


John.
60 oldjohn is offline  
Old 13th Apr 2019, 10:54 pm   #9
turretslug
Dekatron
 
turretslug's Avatar
 
Join Date: Nov 2011
Location: Surrey, UK.
Posts: 4,385
Default Re: SMD Voltage Regulator

LM1117-3.3 a bit old hat but very widely available for trivial money in SMD. ISTR absolute max 20V, recomended max 15V, so may be on thin ice. An appropriate input dissipation burden resistor and quality decoupler will help to catch automotive spikes too, but I always feel that if you're not an exacting car industry bean-counter, then it's worth going OTT with all the spike-catching you can muster here- Rs, Ls, Cs diodes, MOVs etc, less than the cost of a pint will give peace of mind in this respect!
turretslug is offline  
Old 14th Apr 2019, 1:21 am   #10
Terry_VK5TM
Nonode
 
Terry_VK5TM's Avatar
 
Join Date: Oct 2010
Location: Tintinara, South Australia, Australia
Posts: 2,324
Default Re: SMD Voltage Regulator

TLV70233QDBVRQ1

Automotive voltage regulator 3.3v, not expensive - 59c US from Mouser
__________________
Terry VK5TM
https://www.vk5tm.com/
Terry_VK5TM is offline  
Old 14th Apr 2019, 11:09 am   #11
Herald1360
Dekatron
 
Herald1360's Avatar
 
Join Date: Feb 2007
Location: Leominster, Herefordshire, UK.
Posts: 16,526
Default Re: SMD Voltage Regulator

If you add some series resistance in the protection/decoupling ahead of the regulator you can shift most of the dissipation to that, especially if load is fairly constant.

A bit questionable, but very handy in units operating in high magnetic fields before MHz switchers that could use air cored inductors came along.
__________________
....__________
....|____||__|__\_____
.=.| _---\__|__|_---_|.
.........O..Chris....O
Herald1360 is offline  
Closed Thread

Thread Tools



All times are GMT +1. The time now is 8:57 am.


All information and advice on this forum is subject to the WARNING AND DISCLAIMER located at https://www.vintage-radio.net/rules.html.
Failure to heed this warning may result in death or serious injury to yourself and/or others.


Powered by vBulletin®
Copyright ©2000 - 2024, vBulletin Solutions, Inc.
Copyright ©2002 - 2023, Paul Stenning.