10KV 1000:1 passive probe PWB

Schematic

     The 1756 PWB is a platform for building a 1000:1 passive scope probe designed for a scope input of 1M ohms and 15pF nominal.

PWB Specs

• 3.600" long x 0.600" wide x 0.062" thick
• Sized to fit inside a 5/8" tube
• 1mm slots under each input R and C for high voltage potting

Recommended series resistors

• Vishay part number CRMA1210AF4M99FKEF
• 15 x 4.99M resistors for a total of 74.85M
• 1250V voltage rating
• 360mW power rating
• 1% tolerance
• -55C to +155C temperature rating
• 100ppm/C tempco
• Circuit power load = 90mW per resistor at 10KV input

Recommended series capacitors

• Cornell part number MC12FF500F-F
• 15 x 50pF mica capacitors in series totaling 3.333pF
• 1000V voltage rating
• 1% tolerance
• -55C to +125C temperature rating
• +/-25ppm/C tempco
• Output tuned for 1MOhm and 15pF load
• Circuit voltage load = 667V per capacitor at 10KV input

Recommended shunt components

• 4.99M 1% 1206 resistor (Any part number)
• 76.8K 1% 1206 resistor (Any part number)
• 3300pF 50V 1% COG 1206 capacitor: CalChip GMC31CG332F50NT
• 15pF 1KV 1% COG 1206 capacitor: Murata GCM31A5C3A150FX01D
• Voltage on all shunt components = 10V at 10KV input

Recommended connectors

• Output connector: RF Solutions SMA part number CON-SMA-EDGE-S
• IN/GND connector: Pomona part number 3277 mini banana
• IN/GND mating: Pomona part number 5936-0 mini banana