OSCILLOSCOPE input stage FCALLBOX (VCA VERSION)

Description

This interface board is used by the universal measurement system FCALLBOX described here, but it can be used by another system, the functions are :

- Dual input stages for > 300MHz scope, 8 ranges 160mV to 32V peak (+/-16V) (20mV to 4V by division).

Note : This board most recent than the board interface SCOPE and Frequency meter Interface MODULE FCALLBOX has a bandwidth more flat and the BW tuning is minimal (needed more capacitors adjustement on old version).

This new design has reduced the number of passives components, thanks to the use of a VCA (Variable Gain Amplifier).

Summary

• Schematic

• BOM

• PCB

• Board assembly

• Board wiring

• 3D file

Schematic

Download the schematic here

BOM

Top view Ref Description Manufacturer / reference Price R6,R13,R18,R21 Resistor 0R 5% 0603 All brand ---- R3,R16 Resistor 18R 5% 0603 All brand ---- R1,R17 Resistor 20R 1% 0603 All brand ---- R2,R19 Resistor 402R 1% 0603 All brand ---- R4,R5,R14,R15 Resistor 49R9 1% 0603 All brand ---- R25,R26 Resistor 1K 5% 0603 All brand ---- R23,R24 Resistor 1.5K 5% 0603 All brand ---- R9,R10 Resistor 82K 1% 0603 All brand ---- R7,R12 Resistor 100K 1% 0603 All brand ---- R8,R11 Resistor 820K 1% 0603 All brand ---- C5,C7,C14,C21,C23,C27,C30,C33,C38,C41,C44,C45,C47,C48 Capacitor 100nF 50V 10% X5R 0603 All brand ---- C15,C17,C32,C34,C46,C49,C50,C51,C52 Capacitor 10uF 6.3V 10% X5R 0603 All brand 19 x 0.1€ C16 Capacitor 10nF 50V 10% X5R 0603 All brand ---- C1,C10,C26,C39 Capacitor 33pF 50V 10% COG 0603 All brand ---- C9,C13,C18,C25,C28,C29 Capacitor 47pF 50V 10% COG 0603 All brand ---- C4,C6,C19,C22,C31,C35,C40,C43, Capacitor 1uF 10V 10% 0603 All brand 4 x 0.03€ C8,C24 Capacitor 1uF 50V 10% X7R 0603 All brand 2 x 0.05€ CV1,CV2 Trimmer capacitor 3-15pF 100V 10% X7R 1210 JR150 3-15pf Knowles 2 x 3.1€ L1,L2 Inductor 22uH or 100uH 1210 EPCOS B82422A1223K100 / TAIYO YUDEN CBC3225T101KR or equivalent 2 x 0.2€ U5 IC PCF8574 I2C extender SSOP20 Texas Instruments PCF8574ATS 1 x 1.3€ U2,U3 IC relay solid state IXYS CPC1017NTR 2 x 0.6€ U4 IC LDO 3.3V 500mA SOT23-5 SPX3819M5-L-3-3 ou MIC5504-3.3YM5-TR 1 x 0.4€ IC1,IC2 IC VCA821 Texas Instruments VCA821ID 2 x 8.98€ U1,U6 IC OPA656 500MHz SOT23-5 Texas Instruments OPA656N/250 2 x 11€ IC3 IC DAC dual channel 12bits Microchip MCP47FEB22A1-E/ST 1 x 2.60€ U7 IC SP6661EN 200mA charge pump inverter MaxLinear SP6661EN or equivalent 1 x 2.60€ D1,D2,D3,D4 Diode schottky SDO323 BAS416 NXP 4 x 0.2€ J4 connector 6pts male 2.54mm All brand 1 x 0.2€ J2,J3,J5,J6 Connector SMA vertical Amphenol 901-144 or equivalent 1 x 0.2€ PCB PCB 80x50mm 2 layers All brand 1 x 4€

Estimated cost in 2021 (Mouser) : around xx€ HT

PCB

The PCB F00134 is 80x50mm.

Download here the PCB manucfacturing files

Board assembly

Do not place the components in pink.

Top view

Picture of the PCB

Download the top view assy (in svg format)     

3D file

Download here 3D file (STEP format)     

Board wiring

Connections with the FPGA Board and the face plate