User Tools

Site Tools



This shows you the differences between two versions of the page.

Link to this comparison view

wavebubble:power_supply [2008/08/16 20:10]
wavebubble:power_supply [2016/01/28 18:05]
Line 1: Line 1:
-====== Power Supply ====== 
-==== Power supply notes ==== 
-Due to the various odd voltages required by RF stages, there are no less than 4 rails: 
-  - 3.3V for digital/​analog wave generation ​ 
-  - 5V for RF gain stage  
-  - 12V for VCO power  
-  - 20-28V for VCO tuning ​ 
-  - If you're using the PLL tuning system, there'​s an additional 2.5V rail (in the PLL section). grr! 
-  * You should adjust the 24V boost converter to be .5V higher than the Vtune_max of the VCOs you're using to conserve power and reduce the chance of messing up the VCO  
-  * Winding your own inductors isnt necessary but if you want to save some $ and you have magnet wire hanging around, go for it.  
-  * Pick R1/R2 to make a voltage divider for your battery input so that the low battery input = 1.1V. You might want to use 1% resistors or measure the 5% ones to get as close as possible. 
-  * If you're using 5V VCOs, you can power it from the gain stage converter or, alternately,​ cut the input trace and tie it to the battery input (~3.7V) and tie the select line low. This will change it to a 5V boost. 
-  * The power supply is rather expensive if you're buying the boost converters. Useful input as to how this can be remedied is appreciated. Currently it seems like some sort of hand-wound multi-tap transformer and a Simple Switcher might be the easiest way.  
-  * Dont place C20, the datasheet suggests it but it seems to make things worse (?) 
-==== Parts List - Power supply ​ ==== 
-^Part no.^Name^Description^Distributor^Qty^Cost^Total^ 
-|J-188-1|SW1|Alternate action push button switch|Digikey|1|$0.95|$0.95| 
-|*TPS79333|IC1|3.3V/​200mA LDO regulator|Digikey/​Mouser|1|$0.53|$0.53| 
-|*LM2733x|IC2|5 (or 7V) DC/DC converter |Digikey|1|$2.58|$2.58| 
-|*LM2731Y|IC2 (alt)|5 (or 7V) DC/DC converter|Digikey|1||| 
-|*LT1301CS8|IC3|12V DC/DC converter|Digikey/​Linear|1|$4.75|$4.75| 
-|*LT1173CS8|IC4|25V+ DC/DC converter|Digikey/​Linear|1|$4.88|$4.88| 
-|CDRH6D28NP-150NC|L1|15uH power inductor|Digikey|1|$1.03|$1.03| 
-|CDRH6D28NP-7R3NC|L1 (alt)|7.3uH (if IC2 is LM2731Y)|Digikey|1||| 
-|CDRH6D28NP-330NC|L2,​ L3|33uH power inductor|Digikey|2|$1.03|$2.06| 
-|0.1uF 1206 ceramic capacitor|C2,​ C3 C7, C9, C11, C13, C16, C17|0.1uF ceramic filter capacitor|Mouser|8|$0.08|$0.64| 
-|1.0uF 1206 ceramic capacitor|C4,​ C6, C12, C15, C19|1.0uF ceramic filter capacitor|Mouser|5|$0.18|$0.90| 
-|UWX0J101MCL1GB|C1|100uF 6.3V input filter capacitor|Mouser|1|$0.17|$0.17| 
-|UWX0G101MCL1GB|C5|100uF/​4V filter capacitor|Mouser|1|$0.17|$0.17| 
-|TPSC107K010R0100|C10|100uF/​10V low ESR tantalum capacitor|Digikey|1|$1.18|$1.18| 
-|TPSC686K016R0200|C14|68uF/​16V low ESR tantalum capacitor|Digikey|1|$1.44|$1.44| 
-|B45197A6226K409|C18|22uF/​35V low ESR tantalum capacitor|Digikey|1|$1.40|$1.40| 
-|390-550pF 1206 ceramic capacitor|C20|feed foward capacitor for 5V regulator|Digikey|1| ​   ​ 
-|510K 1206 5% resistor|R1|Chosen value resistors for low battery detect: R1/​(R1+R2)*Vlow = 1.1|Digikey/​Mouser|1|$0.08|$0.16| 
-|220K 1206 5% resistor|R2|Chosen value resistors for low battery detect: R1/​(R1+R2)*Vlow = 1.1|Digikey/​Mouser|1|$0.08|$0.16| 
-|39K 1206 5% resistor|R3|Boost voltage reference resistor for 5V|Digikey/​Mouser|1|$0.08|$0.08| 
-|12K 1206 5% resistor|R4|Boost voltage reference resistor for 5V|Digikey/​Mouser|1|$0.08|$0.08| 
-|2K 1206 5% resistor| R5|LED choke resistor|Digikey/​Mouser|1|$0.08|$0.08| 
-|50K 1206 resistor|R6|Boost voltage reference resistor for 24V|Digikey/​Mouser|1|$0.08|$0.08| 
-|1M 1206 resistor|R7|Boost voltage reference resistor for 24V|Digikey/​Mouser|1|$0.08|$0.08| 
-|SS14|D1, D2, D3|Schottky Diode (at least 1A/​20V)|Digikey/​Mouser|3|$0.30|$0.90| 
-* Can be sampled for free at low quantities ​ 
-==== Power supply assembly ​ ==== 
-coming soon... 
/home/ladyada/public_html/wiki/data/pages/wavebubble/power_supply.txt · Last modified: 2016/01/28 18:05 (external edit)