minikv bill of materials, rev 2

Components marked "crit" are critical and should be populated with exactly the recommended manufacturer part number in the table. Reasons for these critical parts are explained below so they may be substituted if absolutely necessary, but do this with care.

Components with no part number are common parts expected to be provided by the builder according to the description.

Parts with reference numbers greater than 10 are on the secondary winding board.

Part Description Crit Manufacturer Manufacturer's part number
C1 Capacitor, MLCC, 10µF, 25V, 0805
C2, C4 Capacitor, MLCC, 100nF, 25V, 0603
C3 Capacitor, MLCC, 2.2nF, 25V, 0603
C5 Capacitor, MLCC, 15nF, 100V, C0G, 1206
C11-12 Capacitor, MLCC, 6.8nF, 2kV, X7R, 1210 KEMET C1210C682MGRAC7800
C13 Capacitor, MLCC, 27nF, 2kV, X7R, 2220 KYOCERA AVX 2220GC273KAZ1A
D11-12 Diode, 2kV, 500mA, trr ≤ 500ns, SMA Micro Commercial Co FM2000GP
J1 Header, shrouded, 1x12, 2.0mm JST B12B-PH-K-S(LF)(SN)
L1 Inductor, 220µH, 1A, 10x10mm Yes Bourns SRN1060-221M
L11 Inductor, 1mH, 15mA, 1007 Taiyo Yuden LB2518T102K
Q1, Q2 Transistor, NPN, 100V, 1A, low Vcesat, SOT-23 Yes Nexperia PBSS8110T,215
R1 Resistor, 10M, 1%, high voltage, 2010 Yes Bourns CHV2010-FX-1005ELF
R2 Resistor, 330k, 1%, 0603
R3 Resistor, 7k5, 1%, 0603
R4 Resistor, 1M, 1%, 0603
R5 Resistor, 68k, 1%, 0603
R6, R11 Resistor, 430, 5%, 0.4W, 0805 Rohm Semi ESR10EZPJ431
U1 Step-down regulator, 30V, 1.2A, 1.4MHz Yes RYCHIP RY8310
n/a Planar E-core, 22x16mm Yes Ferroxcube E22/6/16/R-3F36
n/a Planar E-core plate, 22x16mm Yes Ferroxcube PLT22/16/2.5/S-3F36
n/a Planar E-core transformer clamp Yes Ferroxcube CLM-E22/PLT22

L1: "Critical" due to proprietary footprint. If you can find one that fits, go for it. Irms and Isat should both be 1A or higher.

Q1, Q2: These are low-Vcesat transistors meant for use in SMPS circuits. Using "normal" transistors in place of these may cause overheating and failure. If needed, Zetex and Nexperia have many alternatives.

R1: This resistor must permit continuous operation at up to 2000V and have a power rating of at least 250mW. Don't just filter for "high voltage" at Digi-Key, check for "maximum working voltage" in the datasheet.

U1: This circuit can be made to run on any similar synchronous buck converter, but the pinout needs to match, and the loop compensation will likely need to be adjusted.

Transformer core components: These are completely critical, the board is designed around them. If you can find a piece of similar ferrite material that will fit in the same place, it might work, but don't count on it. If this piece is obsoleted we'll have to make a new minikv.

Last modified: Sat Dec 3 17:44:09 MST 2022. Converted from projects/minikv/
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