Power Converters

Calculations

Fraction Power Loss

$V_{\text{IN}}$ Voltage on input ($V_{\text{IN}}<BV_{\text{DS}}$), and $I_{\text{switch}}$ Switching current,

• Max switching power: ${\textstyle P_{\text{total}}={\frac {1}{2}}I_{\text{switch}}V_{\text{IN}}}$
• Due to $R_{\text{DSON}}$ loss: ${\textstyle P_{{\text{loss}}R_{\text{DSON}}}=R_{\text{DSON}}I_{\text{switch}}^{2}}$
• Due to $C_{\text{DS}}$ loss: $C_{\text{DS}}V_{\text{IN}}^{2}f_{\text{switch}}$

Total loss:

$P_{\text{loss total}}/P_{\text{total}}=2R_{\text{DSON}}{\frac {I_{\text{switch}}}{V_{\text{IN}}}}+C_{\text{DS}}f_{\text{switch}}{\frac {V_{\text{IN}}}{I_{\text{switch}}}}$

Main MOSFETs

P channel

• FDS9953A, digi-key FDS9953ACT-ND, max 2.9 A cont, typ 2.5/max 3.4 nC, <23 ns on/off time (fairchild package drawing)

N Channnel

• SSM6N58NU, digi-key SSM6N58NULFCT-ND, max 4A continuous, 1.8nC gate charge, 29/9 ns on/off time, dual, EUR 0.34 (25 stuks)
• Or, GaNFET: EPC2014, 917-1018-2-ND

Drive of main mosfets

Comparators

• MAX9012EUA+ digi-key MAX9012EUA+-ND: typ 20/30 mA short, prop delay 9ns, rise/fall 3 ns, 2.2 EUR (dual)
• 584-AD8564ARUZ-R, mouse, short current??? in tabel niet meer dan +/- 10 mA, in text 'can deliver up to 40 mA per channel'. Rest wel goed (en quad).
• LMV7219M7, Farnell 1468946: typ 65 mA short, rise/fall time 1.3ns, prop delay typ 7, max 19 ns, EUR 2.96/stuk (1.6 voor 50)
• NCX2200, farnell 2164804: typ 68 mA short, 10 ns transition time, ... 800ns prop delay...

MOSFETs

• N/P: DMG1029SV, digi-key, mouser: typ 0.3 nC, 15 ns, 6 Ohm, EUR 0.43
• N/P: DMC2400UV-7, digikey, 0.5 nC, Vgs(th)=0.9V, 0.48 Ohm (Vgs=4.5V), EUR 0.25, SOT563
• N/P: DMG1016UDW-7, digikey, typ 0.74 nC (740nC datasheet), Vgs(th)=1V , RdsON=0.5 Ohm (Vgs=4.5V), SOT363 (pitch 0.65)

Other Components

• -5V voltage regulator: [1], digi-key, EUR 0.76, D2PAK

Inductive Heating Power Transfer

Coils

Indactance calculator, or simpler, this one gives different/wrong? results

• primary coil: length=110mm, diameter=11mm, N=100 => 9.7 uH,
  • resistance: 100*3.14*10e-3/(3.14*.5e-3**2)*16.9e-9 = 68 mOhm
• secondary coil: length=100mm, diameter=10mm, 1mm thick brass:
  • inductance=8.0 uH/100^2=0.80nH (8.0uH is inductance for 10mm diameter coil)
  • resistance: 65e-9 [Ohm m] * 3.14*5e-3 / (1e-3*100e-3) = 20 u Ohm
  • L/R fall-off time: 0.8e-9/20e-6 = 40 us.
  • resistance 'seen' on primary coil: 20e-6*100**2 = 0.2 Ohm.
• secondary coil, stainless steel ([resistivity = 690 nOhm m, chemistry.about.com)
  • resistance: 690e-9 * 3.14*10e-3 / (1e-3*110e-3) = 196 u Ohm
  • L/R fall off time: 0.8e-9/ 217 u Ohm = 4.06 us
  • resistance 'seen' on primary coil: 196 *100**2 = 1.96 Ohm, so with 200 primary turns, will be 7.9 Ohm.

$L=\mu _{0}{\frac {N^{2}A}{l}}.$

Misc

• Load resistors: 15 ohm: 1623729-6, digikey, of 4.7 ohm [2] (both EUR 1.2)
• LDO with Ceramic C's: ADP3338, LT1964-5 (digikey)
  • 1.2V: MCP1700T-1202E/TT, digikey (stable with 1.2 uF ceramic C, EUR 0.4)
  • 2.5V: MCP1700T-2502E/TT, digikey
  • 3.3V: MCP1700T-3302E/TT, digikey
• Coils (to measure current peaks/drops): 8nH, 2.3mOhm, 4A: AIAC-1512C-8N0K-T, digikey
• Layouts: Solderrm-d

Lattice

• Add Lattice FPGA, for example ICE40LP384-SG32 digikey (heeft geen PLL!)
• ICE40HX1K-VQ144 does have PLL (?) (HX variants seem to be the only ones with pins & PLL)
• ICE40UL1K-SWG16ITR50 does have PLL (4x4 GBA, 0.35mm pitch, ...)
  • iCE40FamilyHandbook.pdf, iCE40LPHXFamilyDataSheet.pdf
• Lattice SPI progrmamming protocol: iCE40ProgrammingandConfiguration.pdf.
• Pinout iCE40-LP384
• PackageDiagrams.pdf
• Lattice layout gide: PCBLayoutRecommendationsforLeadedPackages.pdf, and SolderReflowGuideforSurfaceMountDevices.pdf