I need the attached amplifier on a PCB board. The amplifier will amplify geophone signal then the amplified signal will go through ADS1115 analogue to digital converter to the raspberry pi to read the analogue data. Can you make the the amplifier by adding the ics, resistors and capacitors?
Description of the circuit:
1) Short block diagram (signal flow)
Geophone (differential)
→ series Rs + AC coupling caps
→ INA333 (G1 ≈ 100, REF = Vbias)
→ Stage-2 non-inverting op amp (G2 = 20, referenced to Vbias)
→ Rseries + anti-alias cap to Vbias
→ ADS1115 A0 (ADS1115 A1 = Vbias) → Raspberry Pi (I2C)
2) Full parts list (recommended)
Geophone (your sensor)
INA333 (instrumentation amp) — low-noise single-supply INA
Single-supply rail-to-rail op amp (second stage). Examples (pick one available locally): OPA333, MCP6002, TLV2372 — must run on 3.3 V and be rail-to-rail input/output. (Check datasheet for your chosen part.)
ADS1115 I2C ADC breakout (3.3 V)
Pi (any model with I2C)
Resistors (metal film, 1%):
Rb1, Rb2 = 100 kΩ (bias divider)
Rinput_bias (x2) = 100 kΩ (each INA input → Vbias)
Rs (series at each geophone wire) x2 = 1 kΩ
RG (INA gain resistor) = 1.01 kΩ (1% metal film) → sets INA G1 ≈ 100
Stage2: R2 (= resistor to Vbias) = 10 kΩ (1%) ; R1 (= feedback from out to – input) = 190 kΩ (1%) → G2 = 1 + R1/R2 = 20
Rf_out (series to ADS) = 1 kΩ
Capacitors:
Cb1 = 10 μF electrolytic (Vbias → GND)
Cb2 = 0.1 μF ceramic (Vbias → GND, place very close to INA REF pin)
Ccouple (x2) = 2.2 μF non-polarized (film or ceramic if available) — AC couple geophone leads to INA inputs
Cf_aa (anti-alias) = 1.6 μF (shunt from ADC node to Vbias) — use film or X7R ceramic
Optional small cap (10–100 pF) across R1 or between op amp pins for stability if you see oscillation
