MarkII

REG_01 PCB on gdrive

Adjustable regulator on Amazon

Generator-Electronics From First Generation

Regulator Search

LTC3114-1: min Vin = 2.2V, min Vout = 2.7V,  max V_in = 45V

LTC3115-1: min Vin = 2.7V

LTC3115-2: min Vin = 2.7V

LT8494: min Vin = 1.0V, datasheet: http://cds.linear.com/docs/en/datasheet/8494fa.pdf

LT8495, min Vin = 1.0V, plus POR and watchdog.  datasheet: http://cds.linear.com/docs/en/datasheet/8495fb.pdf

LT8631, min Vin = 3.0V, buck-only, datasheet: http://cds.linear.com/docs/en/datasheet/8631fb.pdf

LTC3114-1

• Datasheet:  http://cds.linear.com/docs/en/datasheet/31141fb.pdf
• Eval Board Manual: http://cds.linear.com/docs/en/demo-board-manual/DC1821BF.PDF
• Eval Board home page on Linear Tech:  http://www.linear.com/solutions/7368 
• Chip home page on Linear Tech: http://www.linear.com/product/LTC3114-1 
• ICs on DigiKey:  https://www.digikey.com/products/en/integrated-circuits-ics/pmic-voltage-regulators-dc-dc-switching-regulators/739?k=ltc3114&k=&pkeyword=ltc3114&pv7=6&FV=fffc00a1%2Cffe002e3%2C142c03b2&mnonly=0&ColumnSort=0&page=1&quantity=0&ptm=0&fid=0&pageSize=25

• Eval Board on DigiKey ($175): https://www.digikey.com/products/en?FV=fffc00a1,ffe00318&k=ltc3114&pkeyword=ltc3114
• Eval Board on Arrow: https://www.arrow.com/en/reference-designs/dc1821b-demo-board-using-ltc3114edhc-1-27-to-40v-vin-5vout--up-to-1a-sync-buck-boost-converter/0ac86dbcba32c813d5b76e55c415ec64
• Eval Board direct from Linear Technology: http://www.linear.com/purchase/DC1821B

LTC3115-2

• http://www.linear.com/product/LTC3115-2
• http://cds.linear.com/docs/en/datasheet/31152fa.pdf 
• https://cds.linear.com/docs/en/datasheet/31152f.pdf

The LTC 3115-2 is a high voltage monolithic synchronous buck-boost DC/

DC converter optimized for applications subject to fast (<1ms) input voltage transients.

kind of interesting btw: https://www.diymodules.org/eagle-show-library?type=usr&id=2683

make a new part from eagle internal reference library here: https://www.youtube.com/watch?v=e5zL3gUN4jw

•  online search for eagle symbols and libraries.  no LTC3*, but TSSOP16s can be found

http://sparkle.tribbeck.com/eaglesearch2/pack.php

Parametric search of dev kits on Arrow:

• https://www.arrow.com/en/categories/power-management/evaluation-development-boards-and-kits/power-management-development-boards-and-kits?filters=Input+Voltage+Range:0VDC%20to%2057VDC|0VDC%20to%2040VDC|0VDC%20to%201200VDC|2.3VDC%20to%2020VDC|2.5VDC%20to%2030VDC;

LM2574

Thread about design errors, gulp: https://forum.allaboutcircuits.com/threads/ltc3115-2-regulator-circuit.101344/

LTC3115: http://cds.linear.com/docs/en/datasheet/31151fb.pdf

LTC3114: http://cds.linear.com/docs/en/datasheet/31141fb.pdf

http://www.linear.com/product/LTC3114-1

• LM2574 Simple Switcher

http://www.digikey.com/product-search/en?pv41=634&k=lm2574&mnonly=0&newproducts=0&ColumnSort=0&page=1&stock=1&quantity=0&ptm=0&fid=0&pageSize=25

          HV = high voltage

          ADJ = adjustable

HVNADJ for DIP,

HVMADJ for SMD

HVMX is reel for SMD

DataSheet

• LM2574

Choosing potentiometer for 1.23 to 5.33V output swing:

• Vout = Vref * ( 1 + R2 / R1 ).  Vref = 1.23V.  5k > R1 > 1k.     (From the datasheet)
• R1 = 1k, R2 = 0-5k,    Vref = 1.23 <-> 6.23V
• max_voltage = 1.23 + 1.23 * ( 5k / R1 )
• v_max / 1.23 = 1 + R2 / R1
• ( v_max / 1.23 ) - 1 = R2 / R1
• R1 = R2 / [ ( v_max / 1.23  ) - 1 ]
• R2 = 5k, v_max = 5
• R1 = 5k / ( ( 5 / 1.23 ) - 1 ) = 1631.

• What if R1 = 1.5k, a common value?  ( Common resistor values )
• v_max = 1.23 + 1.23 * ( 5k / 1.5 ) =  5.33 V.  This is fine.

Resistor Shopping

• Basic search for 1.5k, 1% tolerance on digikey   Choice #1    Choice #2   Choice #3   Note: these are expensive, except for the first one
• 5k Potentiometer shopping is on Prefered parts list of MarkII

Eagle libraries for Bourns potentiometers:

• https://github.com/cmonr/Eagle-Libraries.git
• https://github.com/chiengineer/Eagle-Libraries/blob/master/Potentiometers/bourns.lbr 

Op-Amp Hysterisis

• http://www.analog.com/media/en/technical-documentation/application-notes/AN-849.pdf
• http://www.analog.com/library/analogDialogue/archives/34-07/comparators/index.html
• http://www.ecircuitcenter.com/Circuits/op_comp/op_comp.htm
•  

Zener Diode Protection

Theory

• http://www.radio-electronics.com/info/data/semicond/zener-voltage-reference-diodes/applications-circuits.php
• https://en.wikipedia.org/wiki/Zener_diode
• http://www.mycircuits9.com/2012/07/zener-diode-applications.html
• http://www.learningaboutelectronics.com/Articles/Overvoltage-protection-circuit.php
• https://en.wikipedia.org/wiki/Transient-voltage-suppression_diode
• https://dmohankumar.wordpress.com/2012/05/14/design-your-circuit-part-iii-over-voltage-protector/
• http://www.analog.com/library/analogDialogue/archives/46-02/ovp.html

Calculators

• http://www.calculatoredge.com/electronics/zener.htm
• http://www.electricaltechnology.org/2014/03/zener-diode-voltage-regulator-calculator.html
• http://www.petervis.com/electronics%20guides/calculators/zener/zener.html
• http://www.designworldonline.com/calculators/zener-diode-calculator/
• http://ncalculators.com/electronics/zener-diode-calculator.htm