Datasheet

OPA27, OPA37
13
SBOS135C
www.ti.com
FIGURE 16. Ultra-Low Noise “N”-Stage Parallel Amplifier.
2kΩ
Gain = –1010V/V
V
OS
≈ 2µV
Drift ≈ 0.07µV/°C
e
n
≈ 1nV/√Hz at 10Hz
0.9nV/√Hz at 100Hz
0.87nV/√Hz at 1kHz
Full Power Bandwidth ≈ 180kHz
Gain Bandwidth ≈ 500MHz
Equivalent Noise Resistance ≈ 50Ω
Signal-to-Noise Ratio ∝ √N
since amplifier noise is
uncorrelated.
2kΩ
6
2
3
20Ω
6
2
3
6
2
3
2kΩ
6
2
3
6
2
3
OPA37
OPA37
OPA37
OPA37
OPA37
6
Output
2
3
OPA37
N = 10 Each OPA37
2kΩ
2kΩ
2kΩ
2kΩ
2kΩ20Ω
2kΩ20Ω
2kΩ20Ω
2kΩ20Ω
Input